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Can solar and wind power Britain? An update of David MacKay's numbers

174 points by ZeroGravitas 3y ago

RobinL 3y ago
Great post - I've been looking for a serious update to Mackay's numbers for ages. One thing in curious about: developments in fixed wind turbines tech mean they are economically viable in more locations (e.g. deeper water) so can cover more area. But how much more do they produce per square km of deployment than Mackay's estimates? In his book, he has a nice section explaining that bigger turbines have to be spaced out more, so whilst theyre cheaper, they don't produce as much more energy as the headline 'output per turbine' would naively suggest. But modern turbines are higher, so they presumably 'catch' more wind, and windspeeds are more consistent higher up. But I'm curious how big an effect this is.
- cycomanic 3y ago
  I don't MacKays estimates but the cited study seems to assume a capacity factor of 50% for a 15 MW turbine. Average turbine capacity of turbines installed in 2021 was 7.4 MW but all manufacturers seem to have 15+MW designs in the work [1]. So the projection is slightly optimistic IMO. The capacity factor seems slightly more optimistic at 50% as worldwide average seem to have fluctuated between 35 and 45% [2]. Although other numbers are closer to 60% for the UK [3] [1] https://www.energy.gov/eere/wind/articles/offshore-wind-market-report-2022-edition https://www.energy.gov/eere/wind/articles/offshore-wind-mark... [2] https://www.statista.com/statistics/1368679/global-offshore-wind-capacity-factor/ https://www.statista.com/statistics/1368679/global-offshore-... [3] https://windeurope.org/about-wind/daily-wind/capacity-factors https://windeurope.org/about-wind/daily-wind/capacity-factor...
  - yodelshady 3y ago
    Source [3] seems highly suspicious. There's ~24 GW of wind capacity in the UK, the vast majority offshore, and according to Elexon Portal (https://www.elexonportal.co.uk https://www.elexonportal.co.uk, a good public frontend at http://gridwatch.org.uk/ http://gridwatch.org.uk/), which gives realtime grid data, the maximum production was 10. So an average cap factor of 39% is, well sorry it's wrong. And time and time again renewables always seems to take optimistic, if not ludicrous estimates. Mackay's papers is indeed 15 years old, and what do we have now? Extremely expensive power, backed by fossil gas, because if wasn't, people would die. Avoiding 2 deg C and ecosystem collapse is not even vaguely possible anymore. In that time, 40 years ago, France got to 17 g / kWh. That's not a success and, for the literal trillions of ESG money spent, someone should be held accountable for that.
- leoedin 3y ago
  Wind turbine size has an incredible effect on total power generation. The generated power is subject to the square of the blade length, and the cube of the wind velocity (which generally increases as you get further from the ground). Costs don't increase exponentially - so it's better to have fewer big turbines than many small ones. The result is that the wind industry (offshore - onshore is limited by physical size constraints) has been consistently getting bigger every year. https://www.energy.gov/eere/articles/wind-turbines-bigger-better https://www.energy.gov/eere/articles/wind-turbines-bigger-be...
coob 3y ago
I thought the issue with wind in the UK was that its supply is (Scotland) where the demand isn’t (the south). So we’d (a) have to build loads of pylons or expensive underground cables and (b) lose a lot in transmission.
- nradov 3y ago
  That's part of it, but storage for base load is still a more significant issue.
- ebiester 3y ago
  Considering the length of transmission lines in the US, is 500 miles (or so) the constraining factor with transmission?
  - bluGill 3y ago
    For AC. More than that and the ends start to be in different phases of the cycle and so generators fight. DC works over much longer distances.
- ben_w 3y ago
  You would have to build lots of transmission, but the losses aren't particularly significant for high voltage lines — it's only about 1000 km from the Shetland islands to Southampton, and HVDC transmission losses are quoted at 3.5% per 1,000 km. Pricing seems to be a trade secret, but the suggested numbers on the Wikipedia page for the 8 GW cross-channel link were £110M for the converter stations and £1M/km for the undersea cable. I know that a mere back-of-the-envelope calculation isn't worth much more than the used envelope it was written on (doubly so when it is based on guesstimates of the input numbers), but that would be only £1bn for 8 GW or £4bn for 32 GW (compared to actual average usage of 31.5 GW last year), which is the kind of thing that the British government shouldn't blink at but in practice actually faffs and fails at basically all the time. (And the sector is theoretically privatised, so this would have to become a business investment, which in turns will have potential investors ask inconvenient questions like "What's the risk we have cheaper options in 10 years that make this power line redundant? And what about those fusion reactors I keep reading about in the Sunday Times? What if Scotland becomes independent and stops selling you the electricity?")
bigfryo 3y ago
[flagged]
Doches 3y ago
One piece of this really jumped out at me: the projection of overall energy demand to shrink from 2900 TWh to 900 TWh over the next 27 years. The article waives that away by pointing to efficiency gains from electrification and decarbonisation — but that’s just a stupendous change in consumption over a quite short period of time. I would honestly like a deeper explanation of how electrification will produce such a wild decrease! That’s shrinking energy use by more than 2/3, and presumably after taking into account population/industry growth…? Or are the authors just wildly pessimistic (not…unmerited) about Britain’s trajectory over the next quarter-century? What am I missing here?
- steveBK123 3y ago
  It seems sort of nonsensical to project electric usage decline as we move from ICE to EV and from oil/gas heat to heat pump.
  - Scarblac 3y ago
    It's a decline in overall energy, presumably not in electricity.
  - morsch 3y ago
    This is final energy demand and thus presumably includes energy used for heating and transportation that's currently provided via fossil fuels. In fact, that's the point: electrical motors and heat pumps are more efficient, and the final energy demand is reduced. In other words, demand for electricity goes up, total energy demand goes down.
    - steveBK123 3y ago
      That makes more sense if we are talking total energy demand.
      - mikeyouse 3y ago
        Yeah - the original point was about a reduction in total energy demand, not electricity demand.
immibis 3y ago
The answer to the headline question ultimately doesn't matter. Either the answer is "yes", or we figure out how to make the answer "yes", or we all die.
- gpm 3y ago
  There are other options... nuclear power is more expensive but if cost wasn't the issue (e.g. running out of land was) is an option. If cost is the issue there are still risky moonshots like "throw tons of money at fusion" (attacking the cost of nuclear) and "throw tons of money at high temperature superconductor research" (attacking the amount of energy we need), and "geoengineering" (risking screwing it up worse). Not guaranteed to work, but you know, better than rolling over and dying. Also has the side benefit that a lot of the moonshots are worth trying anyways.
  - immibis 3y ago
    Hard reliance on nuclear power is one of the "we all die" options. Didn't we learn our lesson about building a whole civilization on consuming a limited resource dug out of the ground?
    - gpm 3y ago
      Sure, at least with regards to fission, but it plausibly extends the timeline out so that the moonshots are no longer quite so difficult.
    - kristjank 3y ago
      Is it not the case that Uranium and Thorium are not just more abundant than existing fuels, but also about a million times more energy dense? I find it hard to believe running out is a chance we'll face soon.
      - ben_w 3y ago
        Million times more energy dense, yes. More abundant? Depends. There's a lot in the sea, which isn't currently recoverable. There's a lot we could do (but actually don't) with breeder reactors to make more fuel. This means the answer to the question "how long could we last on just nuclear fuel alone?" varies from 5.7 years[0][1] to 4.3 billion years[1]. [0] https://globalwarming-sowhat.com/renewables https://globalwarming-sowhat.com/renewables [1] https://whatisnuclear.com/nuclear-sustainability.html https://whatisnuclear.com/nuclear-sustainability.html
dvh 3y ago
There's a lot of assumptions there, wouldn't it be easier to put some panels on rooftop, car sized battery in the garage and see what happens?
- hn_throwaway_99 3y ago
  The article literally goes into pretty specific detail about how much energy rooftop solar could provide.
  - morsch 3y ago
    I was left wondering why only 8% of roofs quality for rooftop solar. I haven't checked the underlying paper, maybe it has an answer.
    - hn_throwaway_99 3y ago
      That's what I thought was so great about this article. Even if you quadrupled the estimate of total rooftop solar, it is still just a drop in the bucket compared to the total energy generation needed. It's almost not worth talking about because it's such a minor amount of capacity. I didn't read the paper, but from personal experience: 1. Rooftop solar depends on lots of individuals to make an investment to put solar on their houses. If you say "let the government subsidize it", that doesn't really make much sense because the government can get a much better return on each dollar spent by investing in more efficient technologies. 2. Many roofs are not suitable for solar. They are either facing the wrong way, at a bad angle, shaded, or, in my case, too "origami-like". Solar panels need to have minimum clearance fro ridge lines on a roof, which can drastically reduce the total coverable area.
      - Tams80 3y ago
        Exactly. It's a quadruple whammy: 1. Most residences not being suitable for significant generation. 2. The return on investment is decades long (yes, so is double glazing, but that is useful for far more households), not that most households can afford it at all. 3. The total generation capacity is piddle, especially for government investment. 4. The materials that go into making PV panels are horrible to extract. I'm not saying PV panels are useless, but they are not much of anything. Not something my lecturers at uni liked hearing/reading, but lo and behold pretty much nothing substantial has changed since. They're too busy blowing Sustainable Development smoke up their own arses though.
deleted 3y ago
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hn_throwaway_99 3y ago
I thought this was a really excellent post. The thing I liked best about it was how it presented the different set of numbers and didn't try to say "one is wrong or one is right", but instead tried to explain where the numbers came from, and what the outcome would be if some assumptions were wrong so the reader can do their own analysis. What I found particularly helpful: 1. Explaining the difference between MacKay's original "technically possible" vs. "practically possible" supply numbers. I agree with the article, the world has changed a ton since 2008 and I do think much more of that technical possibility is now practical due to changes in tech and attitude. 2. One thing I was cautious about is that the lion's share of final 2050 supply in the updated numbers comes from floating offshore wind, which in my understanding is the least technologically "ready" solution. Can someone with more knowledge comment on this? Is floating wind really as "production ready" as would be needed to match these numbers?
- Blahah 3y ago
  Floating wind is production ready and in production in the UK. The flagship example was Hywind in Scotland which has been in production since 2017. There are several other offshore projects using floating wind, more being converted and a lot more planned for conversion or development. There is quite a lot of investment and encouragement from government. See https://www.great.gov.uk/international/content/investment/sectors/offshore-wind/ https://www.great.gov.uk/international/content/investment/se... for a reasonable overview.
- lovemenot 3y ago
  O'Callaghan et al. successfully retained the baby - MacKay's method - while discarding the bathwater - his 2008 data. There is nothing in principle to prevent scale-up of floating wind, but there is an awful lot of scaling to do. Who really knows? This report probably could use an update ten years hence, but they have done a good job with what is known and can reasonably be predicted.
- iamthemonster 3y ago
  Floating wind is very low in novelty, there is just a cost trade-off depending on water depth. If your water is too deep then structures become too expensive and floating is cheaper in deep water. There is some room for improvement in floating which will get costs down, but it is totally fine to just deploy straight away. But if you can install offshore wind on small structures like <30 metres then get that done first, it's cheaper.
trebligdivad 3y ago
It doesn't seem to mention storage, which for something so wind driven is surprising.
PaulHoule 3y ago
Not one word about storage…
- ZeroGravitas 3y ago
  > To be clear: this does not mean that this is the ‘optimal’ electricity mix in 2050. Not least because energy storage costs would be very high. We would probably want to diversify a bit, not least to help with grid balancing. Before all of the nuclear fans get mad: I think there’s room for nuclear in there too. > But the point still stands: it seems we have a lot of untapped solar and wind resources and they could make up a large chunk of our grid, even if they’re not 100% of it.
Tade0 3y ago
There's one component that could not have been a part of the 2008 analysis: batteries. Global annual manufacturing capacity is currently enough to produce 50min worth of storage for the whole world (as a fraction of annual electricity production). That's not a lot and it's not utilized fully, but still well within the capabilities required to shave off the evening and morning peaks - assuming batteries last more than 5 years, which is a conservative estimate. Nuclear would have been a great component here, but IIRC Hinkley Point C is still under construction and will remain so until 2027.
- FredPret 3y ago
  Powering the whole world on batteries for 50 minutes - that's nuts. Any sources for this? I wonder how long these batteries last. If we can get our battery capacity to grow to 12-24 hours, it removes a lot of the concerns around solar. The other remaining issue would be recycling that amount of batteries.
  - edent 3y ago
    I have a 4.8kWh battery installed at home. That's usually good for 30-50% of my daily usage. It charges from solar and cheap overnight electricity.
    - FredPret 3y ago
      I had a walkman that could barely get through two tapes on a set of batteries. Now people are running their houses on it. Wild!
  - ben_w 3y ago
    I'm not the original poster, but here's my estimate and source for the same: 2022 production: 1.57 TWh of batteries - https://www.iea.org/data-and-statistics/charts/lithium-ion-battery-manufacturing-capacity-2022-2030 https://www.iea.org/data-and-statistics/charts/lithium-ion-b... 2022 total global electricity use: 28,527.8 TWh - https://ourworldindata.org/grapher/electricity-demand?tab=chart&country=~OWID_WRL https://ourworldindata.org/grapher/electricity-demand?tab=ch... 1.57 TWh / (28527.8 TWh/y) = 28.93 minutes. - For stuff like this I assume batteries will have 50% capacity after 1000 cycles even though this always gets surprised responses insisting they're good for far more cycles, as I think lowballing is a safer assumption. You can always just multiply as appropriate for different assumptions about cycles. However, that last 50% is still useful in this context, so that's half an hour every day going down to 15 minutes/day after 3 years; assuming it's exponential decay, I think that's a steady state equivalent to 4.3-ish times the production rate? Not sure though[0]. Same graph also forecasts 6.79 TWh/y manufacture in 2030, which is ~2 hours each day instantaneous or 8.6 hours steady-state if my previous assumptions were correct. At that scale, I suspect you also need to start accounting for the impact from variable day lengths meaning there won't be demand to fully discharge the batteries 365 days of the year, and also that demand is lower at night while all the demand numbers I've given assume constant use. A realistic estimate also needs to account for the impact of nighttime renewables getting used preferentially, further lowering the overall frequency with which the batteries need to go through a complete cycle, and conversely increasing battery demand to account for how well the grid they're connected to can compensate for renewable-unfriendly weather, but that's not the topic of this sub-thread. Also also, I expect these batteries will probably mostly get used by cars. Finally, I think recycling is a red herring because I can't believe that getting metals out of batteries is harder than getting the same metals out of literal rocks in the ground. [0] integral from 0 to infinity of 2^(-x/3) for a 3 year capacity halving time?
Kon5ole 3y ago
A common issue with all predictions from a few years ago is that they failed to predict the 90% fall in cost of solar panels. We see a similar thing today when battery storage is dismissed as being too expensive. Unfortunately, current policies are often based on predictions from a few years ago.
- nradov 3y ago
  Battery storage has excellent long term potential but costs are falling much more slowly than with solar panels. There are some significant constraints on raw materials supplies. Those can eventually be worked through but it will take longer.
  - Kon5ole 3y ago
    You may be right of course, but I believe the reason for the slow drop is mostly because most of the battery factories currently under production are not online yet and EV makers are still grabbing all the batteries they can get. VW just started building one of their planned 6 last year. Once the transition to EV's is mostly done and car sales fall to normal levels there will be an immense surplus of battery production capacity. My understanding is also that LFP batteries have basically eliminated the raw materials bottleneck, which was another development that few analysts (or anyone else) were able to predict just a few years ago.
    - tooltalk 3y ago
      >> My understanding is also that LFP batteries have basically eliminated the raw materials bottleneck, << the casuality between the raw material supply bottleneck and LFP would be difficult to demonstrate. LFP has lower energy density and would have required more lithium to get equivalent KWh than what is normally required by high-energy, high-nickel batteries (eg, NCM/A); therefore higher lithium demand, but ... The price of lithium, and other battery raw materials, however, plunged by 75% since last Novemember peak (still falling) -- it's widely understood that the drop is largely caused by slower than expected EV demand (and oversupply). >> but I believe the reason for the slow drop is mostly because most of the battery factories currently under production are not online yet... << GM forecasted earlier this year that their (Ultium) cell cost would drop to $87/KWh by 2025; just last week, GM reported a 40% drop in their cell cost YoY. Sure, there is 400+GWh new US battery production coming up in 2025-2026 and the commodification/mass-production of made batteries would accelerate further price drop.
conjecTech 3y ago
I love this kind of hypothetical analysis, but I'd also like to point out there are already people making real strides towards this on an individual level in the UK. Youtube channels like ElectricVehicleMan catalog what a conscientious person can practically accomplish by themselves with readily available solutions today. I've particularly been impressed by the synergies between rooftop solar, battery storage, and combined heat-pump hydronic heat/hot water solutions. It seems plausible that even a person in a typical row house could offset most of their household consumption with solutions that will end up with a reasonable return over time. https://www.youtube.com/@ElectricVehicleMan/videos https://www.youtube.com/@ElectricVehicleMan/videos
divbzero 3y ago
As OP mentions, David MacKay’s Sustainable Energy: Without the Hot Air is available for free online: https://www.withouthotair.com/ https://www.withouthotair.com/ The book provides an excellent overview of how different forms of energy production and consumption add up and which energy solutions could make a real impact. I strongly recommend reading it as context for these updated numbers.
- cycomanic 3y ago
  I haven't read the book, but my impression from reading this Blog post is very poor. He seems to have written a book dismissing renewables by assuming fixed technology/costs from 2008 for projection into the future (if everybody did this companies would not invest in anything). On top of that he even hand waved the rest away by saying their installations would not be accepted by the public. That seems to me that he was set out to dismiss solar and wind and just looked for numbers to confirm this. Generally I believe if you want to show the feasibility of a technology you should be conservative in your estimates, and if you want to dismiss it you should be optimistic in your estimates. Ideally you show both conservative and optimistic projections.
  - PaulDavisThe1st 3y ago
    > He seems to have written a book dismissing renewables by assuming fixed technology/costs from 2008 for projection into the future Your impression is incorrect. As the blog post notes, the problem is that two changes in particular - the reduction in demand, and the absolutely crazy drop in the cost of PV - were far larger than anything mckay was able to reasonable foresee in 2008. > That seems to me that he was set out to dismiss solar and wind and just looked for numbers to confirm this. Almost the opposite, in fact.
    - cycomanic 3y ago
      Ok thanks for the correction, as I said the impression was really only based on my interpretation of the numbers in the Blog post. I will have a look at the book then.
RecycledEle 3y ago
I applaud anyone in any side of any issue who makes a good faith attempt to do the math and use common sense engineering to answer questions.
theptip 3y ago
Some discussion here about storage, but I am interested in modeling around dynamic load shedding / smart grid / “virtual batteries”. Seems to me that as the energy mix moves more towards renewable, to the extent that the renewable-skeptics’ prediction that variability is an issue comes true, then we would have to build gas peaker plants and start charging more for electricity at peak times. In response to this increased market rate delta it would become more viable to invest in dynamic pricing and load shedding/deferring tech. So there is a modeling exercise which looks at the peak time price premium for various levels of increase in peaker plants required as the input variable, and compares that to the viability of virtual batteries at those price deltas as the output. I haven’t seen anything along these lines.
- megaman821 3y ago
  I wonder why oversized hot water tanks don't get more play here. You can heat up the water with excess electricity at basically any time during the day and it should stay hot for about 24 hours if it is well insulated.
  - applied_heat 3y ago
    In New Zealand they were remotely controlling residential customer hot water tanks and heaters with energy stored in hot oil using a “ripple” signal on the power lines … probably in the eighties by the age of the equipment I saw.
  - hwillis 3y ago
    Because people want their hot water to be consistent. Even just a simple timer that kicks on the hot water in the morning would work, but most people want to have their sink still be hot even when they aren't showering. > it should stay hot for about 24 hours if it is well insulated. It takes 50 kWh to heat a 46 gallon tank up to 140 F. That's a ton of energy. Hotter, larger tanks lose even more energy. Instead, get a tankless heater, backing a small heat pump water tank. You get water as hot as you can possibly want, heated whenever you want, and it never goes cold.
    - 3y ago
ilaksh 3y ago
The missing piece is renewable fuels. Having some kind of hydrogen or ammonia, biodiesel etc. from solar and wind and available to supplement real-time generation when needed would make it much more feasible to drop fossil fuels.
- jacquesm 3y ago
  Those would require a massive surplus of Solar, Wind and Hydro which we currently do not have. It may come to that but right now the surplus happens at best during a few minutes to 10's of minutes at peak solar in the summer, the rest of the day (and the rest of the year) we are running at a substantial deficit that is still made up from fossil fuels or nuclear.
  - jeffbee 3y ago
    Is that specific to the UK? Here in California we have all-day-long surpluses of photovoltaic power from January to June.
  - pfdietz 3y ago
    Fortunately we're talking about the future, not the present.
- Tams80 3y ago
  The issue there is that there are a few very vocal renewable energy proponents who just don't get that at all. Merely mention 'hydrogen' and they go into a tirade. Though really, the biggest issue is apathy.
- rcxdude 3y ago
  The efficiency is pretty awful, though. It's quite hard to make the economics of it work (even if the electricity is free) with current fuel prices, which is why it's not really happening. Either the tech needs to get a lot better or the fuel needs to get a lot more expensive (which I don't imagine would be a popular option).
  - 3y ago
DonHopkins 3y ago
Locking up SBF was a step in the right direction. Now do the rest of the energy wasting Bitcoin shills!
jl6 3y ago
One thing I didn't appreciate until recently is how big Britain's EEZ is. If floating wind turbines can be made practical, there is huge opportunity not just for energy self-sufficiency, but for export too. P.S. even if the numbers have been superseded, MacKay's original book is still worth reading because it's so fantastically clear in how it lays out the basis for estimation.
simonbarker87 3y ago
If you haven’t read the book “Sustainability without the hot air” by David MacKay then I strongly recommend it. He makes some assumptions that may not stand the test of time but overall it’s well reasoned and he explains the maths and logic well. His passing is a real loss to UK science. I got to see him speak once, very engaging and his passion was clear.
anovikov 3y ago
One thing i don't like about this analysis is when final energy is expressed in TWh, which is a unit normally reserved for electricity. That creates confusion.
- hn_throwaway_99 3y ago
  Watt-Hours is an extremely common metric to use for total energy when talking about societal-wide energy consumption.
- fghorow 3y ago
  MacKay's entire analysis is posed using KWh (and multiples) as a standard unit for energy. Why? From memory he stated it was because everything would otherwise need to be converted to Joules (or multiples) and KWh were at least a common enough energy unit that people "think" in them for resource estimates.
  - anovikov 3y ago
    Except it makes it easier for people to mentally conflate "energy" with "electricity".
hinkley 3y ago
I just finished, “How Big Things Get Done”, I think on a recommendation some time back from someone on HN. He says that among the projects that tend to be on time and on budget, roads, solar and wind are three of them. While he doesn’t say it, I read this as “all large successful projects start as small successful projects”. Once you’ve built 10 miles of road the next 10miles is mostly more of the same, subsurface conditions notwithstanding. Once you’ve installed three wind turbines in a field installing the rest looks much the same (getting the first one in required solving a bunch of transportation problems of course). The teams just get a little faster with each one, because they are iterating on a pattern they already know. You try to build a nuclear power plant and it might not show up until after the politicians who pushed for it to be built have retired. Which means it might not show up at all because all of the skin has left the game. But if I try to cap my career as governor with a new wind or solar farm? I may actually get to cut the ribbon. It makes me feel a bit better about our prospects that solar and wind are easier logistical problems than repeating the old patterns.
- credit_guy 3y ago
  > You try to build a nuclear power plant and it might not show up until after the politicians who pushed for it to be built have retired. You can try to reactivate nuclear power plants that were shut down. I state I live in (New York) closed 2 nuclear reactors in 2020 and 2021, each providing more than 1 GW of clean electricity. Both reactor were closed because of political pressure. If we were to apply the reverse political pressure, I think we could have them up and running in 5 years, if not sooner.
- tomatocracy 3y ago
  Yes - this is (part of) the motivation for the current idea of "small modular reactors". The idea with SMRs is that if you build the units in a factory, not on site, then things like unexpected ground conditions necessitating costly design changes can be mitigated. Making them smaller might also reduce things like extremely tight tolerances on certain parts leading to potential delays due to having to "throw it out and start again". It's closer to the model used for nuclear submarines which have a better track record in terms of delivery to time and cost than civilian nuclear power.
jonplackett 3y ago
What is the running cost of doing something like this? How often do they need to be replaced and can we afford to do that for the long term? Also - what about the geopolitics. The reason solar is cheap is because china. Do we want all our energy needs to be dependent on China? Although we are still building Hinkley Point C with Chinese investment anyway so ¯\_(ツ)_/¯
- tomatocracy 3y ago
  CGN do still have a stake in Hinkley Point C but they were (probably forcibly) bought out of Sizewell C by the UK govt last year and it's pretty clear future investment from them is no longer welcome.
cm2187 3y ago
Wants to run the full grid on intermittent energy and only one sentence on what happens if there is no wind (on top of typically no sun in the UK). Using nuclear to compensate doesn’t make any sense. If you need to replicate your wind production capacity with nuclear (keep in mind wind, even offshore, can go to zero) and given that nuclear costs the same thing whether you switch it on or not, you might as well spare the construction of wind farms and go full nuclear. As the author points, energy storage is uneconomical. I am also surprised with the idea that electricity consumption will go down. With heating going electric, cars going electric, and mass immigration (hence population growth), that seems counter intuitive to me.
- brutusborn 3y ago
  I completely agree: his introductory mention of the importance of good numbers to inform policy got me hopeful, and then he ignored storage which is possibly the most critical constraint for high renewable penetration. I’m hoping grid scale batteries follow a similar cost reduction to solar but the latest projects which have been built do not inspire confidence. But for some reason this issue is always hand-waved away by the most ardent proponents of renewables. People treat this issue like a football match in that they cheer for their favourite team and ignore their failings.
  - pydry 3y ago
    Grid scale batteries wouldnt be the most cost effective short term storage - pumped storage like coire glas in scotland is. If the UK had another 10 or 15 of those (perfectly doable and economic) that would provide ~8 hours of storage. That would be enough by itself to provide a 94-96% solar/wind powered grid. For that last 3-4% of seasonal/peaking storage and backup nothing beats hydrogen yet. It's only 50% efficient roundtripped but it stores very cheaply for very long periods. If you turned all solar and wind energy into hydrogen and only burned that for electricity it would still be cheaper than power from a nuclear plant. Batteries are probably best used in cars or places which can't connect to pumped storage (which are pretty rare).
    - 3y ago
rawgabbit 3y ago
TLDR. The article claims Britain’s energy needs can be met by renewables. Almost half of estimated renewable output, 1557 of 2896 TWH, will come from floating offshore wind farms.
owenversteeg 3y ago
Fascinating how the 2008 book estimates a maximum renewable generation of 18 kWh per day per person, of which solar PV generating a maximum of 2 kWh per day per person at relatively high cost. Fast forward to 2023 and you can easily generate a yearly average of 2 kWh per day from a single 550W panel in most of the US - and the panel costs under $200 (!) and if you install an actual house setup, more than 1 panel, you can very doably generate an average of >18 kWh per day. It's actually incredible how fast the tech has changed, when you look back!
- jillesvangurp 3y ago
  Some people actually saw this coming. The author fell in the trap of assuming nothing would change or improve. Which is interesting as a thought experiment but otherwise a bit flawed for making any kind of projections. There's a reason we have had so much progress in the last fifteen years: fifteen years ago, investments in this area had been ramping up for a while already. Those investors were making calculated bets on things improving massively. And they weren't wrong. There are some good reasons to continue to be optimistic about the next 27 years (until 2050). That's almost twice the amount of time since the original article from 2008. I expect grid storage is going to be massively successful as prices drop. There are a lot of different solutions emerging currently; many of which are not dependent on any scarce resources. Then learning effects applied to solar and wind should result in more cost reductions. Finally, industrial use of energy is likely to start changing as well. Industrial heating is a big topic with lots of possible solutions.
- alextingle 3y ago
  The book is about the UK, not the US. The UK has much, much less solar potential than the US. The southern most point of Great Britain is further north than the northern most point of the contiguous USA. And it's really, really rainy here too.
  - owenversteeg 3y ago
    I'm very aware, I live on a boat in the Netherlands part of the year and it is off-grid, powered by solar :) You can generate a yearly average of 1.6 kWh per day in London from that single 550W panel, which is only 20% less than the 2 kWh per day I mentioned for the US. As I mentioned the panel is only $200 so if you need more power you can simply put up a few more. Also, obviously, there is a significant range depending on location in both the UK and the US: - in Yuma, AZ you will generate 3.19 kWh per year average (and the lowest, December is only 74% of peak in May!) - in Seattle, WA you will generate 1.95 kWh/day average (with winter 27% of peak) - in Oban, Scotland you will generate 1.35 kWh/day average (with winter 10% of peak) - in London you will generate 1.6 kWh/day average (with winter 17% of peak) The nice thing about solar, though, is that you can just overpanel for whatever your needs are. When the panels are so cheap, under $200 for a giant panel, you can just throw up some more panels and bam, you have enough solar year round. Obviously there are places far enough north to get too much darkness and snow to make year round solar realistic but even in most of the UK it is totally realistic to run off solar year round.
01100011 3y ago
Gonna need a lot of power to run all of the air conditioners that will be running in England soon. Spot electricity prices are going through the roof when the wind stops and the thermometer turns red. You'd think Europe would have already learned its lesson, with the collapse of German industry after losing cheap Russian energy. I guess they're betting they can move all the production to Morocco and other African countries and still survive as a functioning economy.
Guthur 3y ago
On a long enough timeline the answer to this is always no. If the question is can I burn something to release energy the answer is nearly always yes. If the question is can I depend on the weather for anything the answer is invariably eventually no.
adwf 3y ago
Biggest glaring problem for me is that they think it's somehow feasible to build on 7% of all land (for wind and solar combined). The current estimate of all land built on in the UK is only 8%, they think it's doable to nearly double that?
- nl 3y ago
  It's not "building on" in the "estimate of all land built on" sense. It's putting windfarms in existing agricultural land, where the farmland remains but has windmills in it too. [1] gives a range of around 5MW/km2 to 20MM/km2, which assuming 10MW turbines is roughly 1 turbine per square km. [1] https://web.stanford.edu/group/efmh/jacobson/Articles/I/WindSpacing.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/Wind...
  - adwf 3y ago
    Yes, but that's still kinda crazy. One turbine every square km means you'd never be out of sight of a turbine anywhere in the country... No unspoilt views, no hilly (therefore windy) landscape untarnished, etc.
asdefghyk 3y ago
Need to fund the needed storage . The storage capacity must be such that storage can supply through the times when no sun and no ( or minimal) wind. Could be several days. Present batteries are very expensive and need to be replaced every X years.
pfdietz 3y ago
I think MacKay also assumed a fairly large amount of biomass-derived fuel, which uses land very inefficiently.
IceHegel 3y ago
Perhaps I will go my whole life not understanding why nations didn't switch to nuclear fission. Covering 2% of the UK's land in solar panels seems very silly when we can just use the special rocks to boil water. But then again the UK is known for it's sunlight... oh wait
- ngcc_hk 3y ago
  It bite you later as where to put the rock after it was used. Obviously if it is all about economic as well as risk ... but it is not silly.
  - pfdietz 3y ago
    This is not actually the reason nuclear failed. If we had a magic way to make nuclear waste just disappear forever, it would not materially change how much nuclear costs or how things turned out.
- rsynnott 3y ago
  The economics of nuclear are difficult; the cost is _extremely_ front loaded, moreso than virtually any other energy source. It's also awkwardly-sized; in practice, if you want to build a nuclear plant in Europe today, it's going to be in multiples of 1.7GWe and that is that (I think the EPR is literally the only plant currently licensed; there was also a GE one but it's basically vapourware). Not that it's impossible, and small numbers of nuclear plants are under construction (outside China, where the government is throwing money at the problem, and lots are) but it's far from the obvious route these days.
- pfdietz 3y ago
  The reason people didn't switch to nuclear fission was because it was too expensive. This is not hard to understand.
ngcc_hk 3y ago
I thought you need to have the wave/tide based generator as a more stable to compensate when solar and wind is lower down. It is not as efficient but predictable totally (as it is tide).
dm319 3y ago
This was genuinely enlightening to read, comments too.
bluenose69 3y ago
I don't see why the discussion centres on TWh, not TW. The former means something only when a time-frame is stated (per year, in this case). To avoid confusion, that interval ought to be stated in every phrase containing the unit. Which it isn't. This is needlessly confusing. It's not as though W is a confusing unit. Readers have an idea of the wattage of their lights, their stoves, their furnaces.
- robin_reala 3y ago
  Lights, maybe, but I doubt they do for their stoves. And “furnaces” (a en-US term which I guess is approximate to a gas boiler) are nearly always measured in terms of the units of gas they consume in the UK, not their power output.
- rsynnott 3y ago
  Unfortunately the ridiculous TWh/year metric is absolutely standard in the space, and it's far too late to do anything about it now.
physicsguy 3y ago
I read that book at the time, and what I rememember from it was that on top of the things discussed in the article here, there was a fairly lengthy section on peak demand and balancing that with renewables which are intermittent, which formed part of his conclusions.
- audunw 3y ago
  That discussion is probably even more out of date by now. I can’t imagine anyone would predict the scale of battery production happening today. That’s already starting to help with frequency regulation and short term balancing. Then there are the dozens of energy storage solutions designed specifically for grid energy storage which are in early commercial development right now. Ambri’s molten metal battery is one I like to use as an example.
  - physicsguy 3y ago
    There's a long way to get there though - roughly adding ~0.5GW a year of battery storage in the UK and need ~40GW.
    - ZeroGravitas 3y ago
      National Grid just announced that 10GW of storage (and 10GW of renewables) that was already in their connection queue got fast-forwarded by 4 years. The technical innovation was to tell the projects "don't use the local grid if it is already at full capacity" rather than wait 4 years to upgrade the network to a gold plated standard for no good reason.
alextingle 3y ago
This article is extremely disingenuous about MacKay's "arguments against" section. In reality, he was pointing out the objections that might be raised against renewable projects, in a tongue-in-cheek manner. His graphic where >95% of potential renewables are crossed out because of various ridiculous NIMBY arguments is meant to make a point about the practical problems of delivering large projects. It's not a serious prediction... for that, you need to look later in the book, at the sections the author conveniently ignored.
stoobs 3y ago
We've already had numerous periods where the UK's energy needs have been wholly met from renewables, there's actually a very good site where you can see all the stats from the National Grid in near real-time - https://grid.iamkate.com https://grid.iamkate.com If you adjust the time range to all time (it has data for the last eleven or so years), where you can see the total demand dropping, and the renewables overtaking all of the other production sources. To be clear, there is still a decent demand to supply gap, but it is dropping year over year, and given that we've gone from an average of 2.5GW/day to between 10 and 13GW/day in that timeframe, another 20 years or so and we should start meeting demand with renewables alone. I'm hopeful that newer technology in that timeframe coupled with lower costs will encourage more and more generation growth from the sector, especially if more local generation and storage is encouraged, for example home solar/wind and home battery combinations. We'd also end up with a much more resilient power grid if most of the day to day needs can be met from local power systems, with the main grid only needing to supplement high stress periods and industrial and public communal requirements.
- solumunus 3y ago
  This is just electricity though right? A lot of (I assume most) homes in the UK are heated using gas.
  - stoobs 3y ago
    Yes, but there's a huge push at the moment to move to heat-pumps which will remove the need for natural gas for home heating. I did hear that there were also trials to shift from natural gas to either straight hydrogen, or a hydrogen/natural gas mix - but according to the people I had a conversation with, much of the infrastructure will need upgrading as well as all the gas engineers/plumbers needing retraining, given that hydrogen is much harder to keep contained due to the tiny size of the H2 molecule vs that of natural gas (mostly methane), as well as it burning differently so needing different internals for heating systems. Answer is still roughly the same though, give it another 10 years or so and re-evaluate
  - ben_w 3y ago
    Yes to just electricity, I think so for gas heating (I've also been in places in the UK with open hearth wood fires, oil heating, solar thermal, and pure electric, and that's just where I knew the heat source). Assuming the linked calculations are correct, this doesn't matter because all current power consumption can be electrified. Of course, even that's still not sufficient, as the chemical byproducts of several major agricultural and industrial processes also produce greenhouse gases. Fortunately, people are working on those too.

174 points by ZeroGravitas 3y ago

Great post - I've been looking for a serious update to Mackay's numbers for ages. One thing in curious about: developments in fixed wind turbines tech mean they are economically viable in more locations (e.g. deeper water) so can cover more area. But how much more do they produce per square km of deployment than Mackay's estimates? In his book, he has a nice section explaining that bigger turbines have to be spaced out more, so whilst theyre cheaper, they don't produce as much more energy as the headline 'output per turbine' would naively suggest. But modern turbines are higher, so they presumably 'catch' more wind, and windspeeds are more consistent higher up. But I'm curious how big an effect this is.

cycomanic 3y ago
I don't MacKays estimates but the cited study seems to assume a capacity factor of 50% for a 15 MW turbine. Average turbine capacity of turbines installed in 2021 was 7.4 MW but all manufacturers seem to have 15+MW designs in the work [1]. So the projection is slightly optimistic IMO. The capacity factor seems slightly more optimistic at 50% as worldwide average seem to have fluctuated between 35 and 45% [2]. Although other numbers are closer to 60% for the UK [3] [1] https://www.energy.gov/eere/wind/articles/offshore-wind-market-report-2022-edition https://www.energy.gov/eere/wind/articles/offshore-wind-mark... [2] https://www.statista.com/statistics/1368679/global-offshore-wind-capacity-factor/ https://www.statista.com/statistics/1368679/global-offshore-... [3] https://windeurope.org/about-wind/daily-wind/capacity-factors https://windeurope.org/about-wind/daily-wind/capacity-factor...
- yodelshady 3y ago
  Source [3] seems highly suspicious. There's ~24 GW of wind capacity in the UK, the vast majority offshore, and according to Elexon Portal (https://www.elexonportal.co.uk https://www.elexonportal.co.uk, a good public frontend at http://gridwatch.org.uk/ http://gridwatch.org.uk/), which gives realtime grid data, the maximum production was 10. So an average cap factor of 39% is, well sorry it's wrong. And time and time again renewables always seems to take optimistic, if not ludicrous estimates. Mackay's papers is indeed 15 years old, and what do we have now? Extremely expensive power, backed by fossil gas, because if wasn't, people would die. Avoiding 2 deg C and ecosystem collapse is not even vaguely possible anymore. In that time, 40 years ago, France got to 17 g / kWh. That's not a success and, for the literal trillions of ESG money spent, someone should be held accountable for that.
leoedin 3y ago
Wind turbine size has an incredible effect on total power generation. The generated power is subject to the square of the blade length, and the cube of the wind velocity (which generally increases as you get further from the ground). Costs don't increase exponentially - so it's better to have fewer big turbines than many small ones. The result is that the wind industry (offshore - onshore is limited by physical size constraints) has been consistently getting bigger every year. https://www.energy.gov/eere/articles/wind-turbines-bigger-better https://www.energy.gov/eere/articles/wind-turbines-bigger-be...

coob 3y ago

I thought the issue with wind in the UK was that its supply is (Scotland) where the demand isn’t (the south). So we’d (a) have to build loads of pylons or expensive underground cables and (b) lose a lot in transmission.

nradov 3y ago
That's part of it, but storage for base load is still a more significant issue.
ebiester 3y ago
Considering the length of transmission lines in the US, is 500 miles (or so) the constraining factor with transmission?
- bluGill 3y ago
  For AC. More than that and the ends start to be in different phases of the cycle and so generators fight. DC works over much longer distances.
ben_w 3y ago
You would have to build lots of transmission, but the losses aren't particularly significant for high voltage lines — it's only about 1000 km from the Shetland islands to Southampton, and HVDC transmission losses are quoted at 3.5% per 1,000 km. Pricing seems to be a trade secret, but the suggested numbers on the Wikipedia page for the 8 GW cross-channel link were £110M for the converter stations and £1M/km for the undersea cable. I know that a mere back-of-the-envelope calculation isn't worth much more than the used envelope it was written on (doubly so when it is based on guesstimates of the input numbers), but that would be only £1bn for 8 GW or £4bn for 32 GW (compared to actual average usage of 31.5 GW last year), which is the kind of thing that the British government shouldn't blink at but in practice actually faffs and fails at basically all the time. (And the sector is theoretically privatised, so this would have to become a business investment, which in turns will have potential investors ask inconvenient questions like "What's the risk we have cheaper options in 10 years that make this power line redundant? And what about those fusion reactors I keep reading about in the Sunday Times? What if Scotland becomes independent and stops selling you the electricity?")

bigfryo 3y ago

[flagged]

Doches 3y ago

One piece of this really jumped out at me: the projection of overall energy demand to shrink from 2900 TWh to 900 TWh over the next 27 years. The article waives that away by pointing to efficiency gains from electrification and decarbonisation — but that’s just a stupendous change in consumption over a quite short period of time. I would honestly like a deeper explanation of how electrification will produce such a wild decrease! That’s shrinking energy use by more than 2/3, and presumably after taking into account population/industry growth…? Or are the authors just wildly pessimistic (not…unmerited) about Britain’s trajectory over the next quarter-century? What am I missing here?

steveBK123 3y ago
It seems sort of nonsensical to project electric usage decline as we move from ICE to EV and from oil/gas heat to heat pump.
- Scarblac 3y ago
  It's a decline in overall energy, presumably not in electricity.
- morsch 3y ago
  This is final energy demand and thus presumably includes energy used for heating and transportation that's currently provided via fossil fuels. In fact, that's the point: electrical motors and heat pumps are more efficient, and the final energy demand is reduced. In other words, demand for electricity goes up, total energy demand goes down.
  - steveBK123 3y ago
    That makes more sense if we are talking total energy demand.
    - mikeyouse 3y ago
      Yeah - the original point was about a reduction in total energy demand, not electricity demand.

immibis 3y ago

The answer to the headline question ultimately doesn't matter. Either the answer is "yes", or we figure out how to make the answer "yes", or we all die.

gpm 3y ago
There are other options... nuclear power is more expensive but if cost wasn't the issue (e.g. running out of land was) is an option. If cost is the issue there are still risky moonshots like "throw tons of money at fusion" (attacking the cost of nuclear) and "throw tons of money at high temperature superconductor research" (attacking the amount of energy we need), and "geoengineering" (risking screwing it up worse). Not guaranteed to work, but you know, better than rolling over and dying. Also has the side benefit that a lot of the moonshots are worth trying anyways.
- immibis 3y ago
  Hard reliance on nuclear power is one of the "we all die" options. Didn't we learn our lesson about building a whole civilization on consuming a limited resource dug out of the ground?
  - gpm 3y ago
    Sure, at least with regards to fission, but it plausibly extends the timeline out so that the moonshots are no longer quite so difficult.
  - kristjank 3y ago
    Is it not the case that Uranium and Thorium are not just more abundant than existing fuels, but also about a million times more energy dense? I find it hard to believe running out is a chance we'll face soon.
    - ben_w 3y ago
      Million times more energy dense, yes. More abundant? Depends. There's a lot in the sea, which isn't currently recoverable. There's a lot we could do (but actually don't) with breeder reactors to make more fuel. This means the answer to the question "how long could we last on just nuclear fuel alone?" varies from 5.7 years[0][1] to 4.3 billion years[1]. [0] https://globalwarming-sowhat.com/renewables https://globalwarming-sowhat.com/renewables [1] https://whatisnuclear.com/nuclear-sustainability.html https://whatisnuclear.com/nuclear-sustainability.html

dvh 3y ago

There's a lot of assumptions there, wouldn't it be easier to put some panels on rooftop, car sized battery in the garage and see what happens?

hn_throwaway_99 3y ago
The article literally goes into pretty specific detail about how much energy rooftop solar could provide.
- morsch 3y ago
  I was left wondering why only 8% of roofs quality for rooftop solar. I haven't checked the underlying paper, maybe it has an answer.
  - hn_throwaway_99 3y ago
    That's what I thought was so great about this article. Even if you quadrupled the estimate of total rooftop solar, it is still just a drop in the bucket compared to the total energy generation needed. It's almost not worth talking about because it's such a minor amount of capacity. I didn't read the paper, but from personal experience: 1. Rooftop solar depends on lots of individuals to make an investment to put solar on their houses. If you say "let the government subsidize it", that doesn't really make much sense because the government can get a much better return on each dollar spent by investing in more efficient technologies. 2. Many roofs are not suitable for solar. They are either facing the wrong way, at a bad angle, shaded, or, in my case, too "origami-like". Solar panels need to have minimum clearance fro ridge lines on a roof, which can drastically reduce the total coverable area.
    - Tams80 3y ago
      Exactly. It's a quadruple whammy: 1. Most residences not being suitable for significant generation. 2. The return on investment is decades long (yes, so is double glazing, but that is useful for far more households), not that most households can afford it at all. 3. The total generation capacity is piddle, especially for government investment. 4. The materials that go into making PV panels are horrible to extract. I'm not saying PV panels are useless, but they are not much of anything. Not something my lecturers at uni liked hearing/reading, but lo and behold pretty much nothing substantial has changed since. They're too busy blowing Sustainable Development smoke up their own arses though.

deleted 3y ago

[deleted]

hn_throwaway_99 3y ago

I thought this was a really excellent post. The thing I liked best about it was how it presented the different set of numbers and didn't try to say "one is wrong or one is right", but instead tried to explain where the numbers came from, and what the outcome would be if some assumptions were wrong so the reader can do their own analysis. What I found particularly helpful: 1. Explaining the difference between MacKay's original "technically possible" vs. "practically possible" supply numbers. I agree with the article, the world has changed a ton since 2008 and I do think much more of that technical possibility is now practical due to changes in tech and attitude. 2. One thing I was cautious about is that the lion's share of final 2050 supply in the updated numbers comes from floating offshore wind, which in my understanding is the least technologically "ready" solution. Can someone with more knowledge comment on this? Is floating wind really as "production ready" as would be needed to match these numbers?

Blahah 3y ago
Floating wind is production ready and in production in the UK. The flagship example was Hywind in Scotland which has been in production since 2017. There are several other offshore projects using floating wind, more being converted and a lot more planned for conversion or development. There is quite a lot of investment and encouragement from government. See https://www.great.gov.uk/international/content/investment/sectors/offshore-wind/ https://www.great.gov.uk/international/content/investment/se... for a reasonable overview.
lovemenot 3y ago
O'Callaghan et al. successfully retained the baby - MacKay's method - while discarding the bathwater - his 2008 data. There is nothing in principle to prevent scale-up of floating wind, but there is an awful lot of scaling to do. Who really knows? This report probably could use an update ten years hence, but they have done a good job with what is known and can reasonably be predicted.
iamthemonster 3y ago
Floating wind is very low in novelty, there is just a cost trade-off depending on water depth. If your water is too deep then structures become too expensive and floating is cheaper in deep water. There is some room for improvement in floating which will get costs down, but it is totally fine to just deploy straight away. But if you can install offshore wind on small structures like <30 metres then get that done first, it's cheaper.

trebligdivad 3y ago

It doesn't seem to mention storage, which for something so wind driven is surprising.

PaulHoule 3y ago

Not one word about storage…

ZeroGravitas 3y ago
> To be clear: this does not mean that this is the ‘optimal’ electricity mix in 2050. Not least because energy storage costs would be very high. We would probably want to diversify a bit, not least to help with grid balancing. Before all of the nuclear fans get mad: I think there’s room for nuclear in there too. > But the point still stands: it seems we have a lot of untapped solar and wind resources and they could make up a large chunk of our grid, even if they’re not 100% of it.

Tade0 3y ago

There's one component that could not have been a part of the 2008 analysis: batteries. Global annual manufacturing capacity is currently enough to produce 50min worth of storage for the whole world (as a fraction of annual electricity production). That's not a lot and it's not utilized fully, but still well within the capabilities required to shave off the evening and morning peaks - assuming batteries last more than 5 years, which is a conservative estimate. Nuclear would have been a great component here, but IIRC Hinkley Point C is still under construction and will remain so until 2027.

FredPret 3y ago
Powering the whole world on batteries for 50 minutes - that's nuts. Any sources for this? I wonder how long these batteries last. If we can get our battery capacity to grow to 12-24 hours, it removes a lot of the concerns around solar. The other remaining issue would be recycling that amount of batteries.
- edent 3y ago
  I have a 4.8kWh battery installed at home. That's usually good for 30-50% of my daily usage. It charges from solar and cheap overnight electricity.
  - FredPret 3y ago
    I had a walkman that could barely get through two tapes on a set of batteries. Now people are running their houses on it. Wild!
- ben_w 3y ago
  I'm not the original poster, but here's my estimate and source for the same: 2022 production: 1.57 TWh of batteries - https://www.iea.org/data-and-statistics/charts/lithium-ion-battery-manufacturing-capacity-2022-2030 https://www.iea.org/data-and-statistics/charts/lithium-ion-b... 2022 total global electricity use: 28,527.8 TWh - https://ourworldindata.org/grapher/electricity-demand?tab=chart&country=~OWID_WRL https://ourworldindata.org/grapher/electricity-demand?tab=ch... 1.57 TWh / (28527.8 TWh/y) = 28.93 minutes. - For stuff like this I assume batteries will have 50% capacity after 1000 cycles even though this always gets surprised responses insisting they're good for far more cycles, as I think lowballing is a safer assumption. You can always just multiply as appropriate for different assumptions about cycles. However, that last 50% is still useful in this context, so that's half an hour every day going down to 15 minutes/day after 3 years; assuming it's exponential decay, I think that's a steady state equivalent to 4.3-ish times the production rate? Not sure though[0]. Same graph also forecasts 6.79 TWh/y manufacture in 2030, which is ~2 hours each day instantaneous or 8.6 hours steady-state if my previous assumptions were correct. At that scale, I suspect you also need to start accounting for the impact from variable day lengths meaning there won't be demand to fully discharge the batteries 365 days of the year, and also that demand is lower at night while all the demand numbers I've given assume constant use. A realistic estimate also needs to account for the impact of nighttime renewables getting used preferentially, further lowering the overall frequency with which the batteries need to go through a complete cycle, and conversely increasing battery demand to account for how well the grid they're connected to can compensate for renewable-unfriendly weather, but that's not the topic of this sub-thread. Also also, I expect these batteries will probably mostly get used by cars. Finally, I think recycling is a red herring because I can't believe that getting metals out of batteries is harder than getting the same metals out of literal rocks in the ground. [0] integral from 0 to infinity of 2^(-x/3) for a 3 year capacity halving time?

Kon5ole 3y ago

A common issue with all predictions from a few years ago is that they failed to predict the 90% fall in cost of solar panels. We see a similar thing today when battery storage is dismissed as being too expensive. Unfortunately, current policies are often based on predictions from a few years ago.

nradov 3y ago
Battery storage has excellent long term potential but costs are falling much more slowly than with solar panels. There are some significant constraints on raw materials supplies. Those can eventually be worked through but it will take longer.
- Kon5ole 3y ago
  You may be right of course, but I believe the reason for the slow drop is mostly because most of the battery factories currently under production are not online yet and EV makers are still grabbing all the batteries they can get. VW just started building one of their planned 6 last year. Once the transition to EV's is mostly done and car sales fall to normal levels there will be an immense surplus of battery production capacity. My understanding is also that LFP batteries have basically eliminated the raw materials bottleneck, which was another development that few analysts (or anyone else) were able to predict just a few years ago.
  - tooltalk 3y ago
    >> My understanding is also that LFP batteries have basically eliminated the raw materials bottleneck, << the casuality between the raw material supply bottleneck and LFP would be difficult to demonstrate. LFP has lower energy density and would have required more lithium to get equivalent KWh than what is normally required by high-energy, high-nickel batteries (eg, NCM/A); therefore higher lithium demand, but ... The price of lithium, and other battery raw materials, however, plunged by 75% since last Novemember peak (still falling) -- it's widely understood that the drop is largely caused by slower than expected EV demand (and oversupply). >> but I believe the reason for the slow drop is mostly because most of the battery factories currently under production are not online yet... << GM forecasted earlier this year that their (Ultium) cell cost would drop to $87/KWh by 2025; just last week, GM reported a 40% drop in their cell cost YoY. Sure, there is 400+GWh new US battery production coming up in 2025-2026 and the commodification/mass-production of made batteries would accelerate further price drop.

conjecTech 3y ago

I love this kind of hypothetical analysis, but I'd also like to point out there are already people making real strides towards this on an individual level in the UK. Youtube channels like ElectricVehicleMan catalog what a conscientious person can practically accomplish by themselves with readily available solutions today. I've particularly been impressed by the synergies between rooftop solar, battery storage, and combined heat-pump hydronic heat/hot water solutions. It seems plausible that even a person in a typical row house could offset most of their household consumption with solutions that will end up with a reasonable return over time. https://www.youtube.com/@ElectricVehicleMan/videos https://www.youtube.com/@ElectricVehicleMan/videos

divbzero 3y ago

As OP mentions, David MacKay’s Sustainable Energy: Without the Hot Air is available for free online: https://www.withouthotair.com/ https://www.withouthotair.com/ The book provides an excellent overview of how different forms of energy production and consumption add up and which energy solutions could make a real impact. I strongly recommend reading it as context for these updated numbers.

cycomanic 3y ago
I haven't read the book, but my impression from reading this Blog post is very poor. He seems to have written a book dismissing renewables by assuming fixed technology/costs from 2008 for projection into the future (if everybody did this companies would not invest in anything). On top of that he even hand waved the rest away by saying their installations would not be accepted by the public. That seems to me that he was set out to dismiss solar and wind and just looked for numbers to confirm this. Generally I believe if you want to show the feasibility of a technology you should be conservative in your estimates, and if you want to dismiss it you should be optimistic in your estimates. Ideally you show both conservative and optimistic projections.
- PaulDavisThe1st 3y ago
  > He seems to have written a book dismissing renewables by assuming fixed technology/costs from 2008 for projection into the future Your impression is incorrect. As the blog post notes, the problem is that two changes in particular - the reduction in demand, and the absolutely crazy drop in the cost of PV - were far larger than anything mckay was able to reasonable foresee in 2008. > That seems to me that he was set out to dismiss solar and wind and just looked for numbers to confirm this. Almost the opposite, in fact.
  - cycomanic 3y ago
    Ok thanks for the correction, as I said the impression was really only based on my interpretation of the numbers in the Blog post. I will have a look at the book then.

RecycledEle 3y ago

I applaud anyone in any side of any issue who makes a good faith attempt to do the math and use common sense engineering to answer questions.

theptip 3y ago

Some discussion here about storage, but I am interested in modeling around dynamic load shedding / smart grid / “virtual batteries”. Seems to me that as the energy mix moves more towards renewable, to the extent that the renewable-skeptics’ prediction that variability is an issue comes true, then we would have to build gas peaker plants and start charging more for electricity at peak times. In response to this increased market rate delta it would become more viable to invest in dynamic pricing and load shedding/deferring tech. So there is a modeling exercise which looks at the peak time price premium for various levels of increase in peaker plants required as the input variable, and compares that to the viability of virtual batteries at those price deltas as the output. I haven’t seen anything along these lines.

megaman821 3y ago
I wonder why oversized hot water tanks don't get more play here. You can heat up the water with excess electricity at basically any time during the day and it should stay hot for about 24 hours if it is well insulated.
- applied_heat 3y ago
  In New Zealand they were remotely controlling residential customer hot water tanks and heaters with energy stored in hot oil using a “ripple” signal on the power lines … probably in the eighties by the age of the equipment I saw.
- hwillis 3y ago
  Because people want their hot water to be consistent. Even just a simple timer that kicks on the hot water in the morning would work, but most people want to have their sink still be hot even when they aren't showering. > it should stay hot for about 24 hours if it is well insulated. It takes 50 kWh to heat a 46 gallon tank up to 140 F. That's a ton of energy. Hotter, larger tanks lose even more energy. Instead, get a tankless heater, backing a small heat pump water tank. You get water as hot as you can possibly want, heated whenever you want, and it never goes cold.
  - 3y ago

ilaksh 3y ago

The missing piece is renewable fuels. Having some kind of hydrogen or ammonia, biodiesel etc. from solar and wind and available to supplement real-time generation when needed would make it much more feasible to drop fossil fuels.

jacquesm 3y ago
Those would require a massive surplus of Solar, Wind and Hydro which we currently do not have. It may come to that but right now the surplus happens at best during a few minutes to 10's of minutes at peak solar in the summer, the rest of the day (and the rest of the year) we are running at a substantial deficit that is still made up from fossil fuels or nuclear.
- jeffbee 3y ago
  Is that specific to the UK? Here in California we have all-day-long surpluses of photovoltaic power from January to June.
- pfdietz 3y ago
  Fortunately we're talking about the future, not the present.
Tams80 3y ago
The issue there is that there are a few very vocal renewable energy proponents who just don't get that at all. Merely mention 'hydrogen' and they go into a tirade. Though really, the biggest issue is apathy.
rcxdude 3y ago
The efficiency is pretty awful, though. It's quite hard to make the economics of it work (even if the electricity is free) with current fuel prices, which is why it's not really happening. Either the tech needs to get a lot better or the fuel needs to get a lot more expensive (which I don't imagine would be a popular option).
- 3y ago

DonHopkins 3y ago

Locking up SBF was a step in the right direction. Now do the rest of the energy wasting Bitcoin shills!

jl6 3y ago

One thing I didn't appreciate until recently is how big Britain's EEZ is. If floating wind turbines can be made practical, there is huge opportunity not just for energy self-sufficiency, but for export too. P.S. even if the numbers have been superseded, MacKay's original book is still worth reading because it's so fantastically clear in how it lays out the basis for estimation.

simonbarker87 3y ago

If you haven’t read the book “Sustainability without the hot air” by David MacKay then I strongly recommend it. He makes some assumptions that may not stand the test of time but overall it’s well reasoned and he explains the maths and logic well. His passing is a real loss to UK science. I got to see him speak once, very engaging and his passion was clear.

anovikov 3y ago

One thing i don't like about this analysis is when final energy is expressed in TWh, which is a unit normally reserved for electricity. That creates confusion.

hn_throwaway_99 3y ago
Watt-Hours is an extremely common metric to use for total energy when talking about societal-wide energy consumption.
fghorow 3y ago
MacKay's entire analysis is posed using KWh (and multiples) as a standard unit for energy. Why? From memory he stated it was because everything would otherwise need to be converted to Joules (or multiples) and KWh were at least a common enough energy unit that people "think" in them for resource estimates.
- anovikov 3y ago
  Except it makes it easier for people to mentally conflate "energy" with "electricity".

hinkley 3y ago

I just finished, “How Big Things Get Done”, I think on a recommendation some time back from someone on HN. He says that among the projects that tend to be on time and on budget, roads, solar and wind are three of them. While he doesn’t say it, I read this as “all large successful projects start as small successful projects”. Once you’ve built 10 miles of road the next 10miles is mostly more of the same, subsurface conditions notwithstanding. Once you’ve installed three wind turbines in a field installing the rest looks much the same (getting the first one in required solving a bunch of transportation problems of course). The teams just get a little faster with each one, because they are iterating on a pattern they already know. You try to build a nuclear power plant and it might not show up until after the politicians who pushed for it to be built have retired. Which means it might not show up at all because all of the skin has left the game. But if I try to cap my career as governor with a new wind or solar farm? I may actually get to cut the ribbon. It makes me feel a bit better about our prospects that solar and wind are easier logistical problems than repeating the old patterns.

credit_guy 3y ago
> You try to build a nuclear power plant and it might not show up until after the politicians who pushed for it to be built have retired. You can try to reactivate nuclear power plants that were shut down. I state I live in (New York) closed 2 nuclear reactors in 2020 and 2021, each providing more than 1 GW of clean electricity. Both reactor were closed because of political pressure. If we were to apply the reverse political pressure, I think we could have them up and running in 5 years, if not sooner.
tomatocracy 3y ago
Yes - this is (part of) the motivation for the current idea of "small modular reactors". The idea with SMRs is that if you build the units in a factory, not on site, then things like unexpected ground conditions necessitating costly design changes can be mitigated. Making them smaller might also reduce things like extremely tight tolerances on certain parts leading to potential delays due to having to "throw it out and start again". It's closer to the model used for nuclear submarines which have a better track record in terms of delivery to time and cost than civilian nuclear power.

jonplackett 3y ago

What is the running cost of doing something like this? How often do they need to be replaced and can we afford to do that for the long term? Also - what about the geopolitics. The reason solar is cheap is because china. Do we want all our energy needs to be dependent on China? Although we are still building Hinkley Point C with Chinese investment anyway so ¯\_(ツ)_/¯

tomatocracy 3y ago
CGN do still have a stake in Hinkley Point C but they were (probably forcibly) bought out of Sizewell C by the UK govt last year and it's pretty clear future investment from them is no longer welcome.

cm2187 3y ago

Wants to run the full grid on intermittent energy and only one sentence on what happens if there is no wind (on top of typically no sun in the UK). Using nuclear to compensate doesn’t make any sense. If you need to replicate your wind production capacity with nuclear (keep in mind wind, even offshore, can go to zero) and given that nuclear costs the same thing whether you switch it on or not, you might as well spare the construction of wind farms and go full nuclear. As the author points, energy storage is uneconomical. I am also surprised with the idea that electricity consumption will go down. With heating going electric, cars going electric, and mass immigration (hence population growth), that seems counter intuitive to me.

brutusborn 3y ago
I completely agree: his introductory mention of the importance of good numbers to inform policy got me hopeful, and then he ignored storage which is possibly the most critical constraint for high renewable penetration. I’m hoping grid scale batteries follow a similar cost reduction to solar but the latest projects which have been built do not inspire confidence. But for some reason this issue is always hand-waved away by the most ardent proponents of renewables. People treat this issue like a football match in that they cheer for their favourite team and ignore their failings.
- pydry 3y ago
  Grid scale batteries wouldnt be the most cost effective short term storage - pumped storage like coire glas in scotland is. If the UK had another 10 or 15 of those (perfectly doable and economic) that would provide ~8 hours of storage. That would be enough by itself to provide a 94-96% solar/wind powered grid. For that last 3-4% of seasonal/peaking storage and backup nothing beats hydrogen yet. It's only 50% efficient roundtripped but it stores very cheaply for very long periods. If you turned all solar and wind energy into hydrogen and only burned that for electricity it would still be cheaper than power from a nuclear plant. Batteries are probably best used in cars or places which can't connect to pumped storage (which are pretty rare).
  - 3y ago

rawgabbit 3y ago

TLDR. The article claims Britain’s energy needs can be met by renewables. Almost half of estimated renewable output, 1557 of 2896 TWH, will come from floating offshore wind farms.

owenversteeg 3y ago

Fascinating how the 2008 book estimates a maximum renewable generation of 18 kWh per day per person, of which solar PV generating a maximum of 2 kWh per day per person at relatively high cost. Fast forward to 2023 and you can easily generate a yearly average of 2 kWh per day from a single 550W panel in most of the US - and the panel costs under $200 (!) and if you install an actual house setup, more than 1 panel, you can very doably generate an average of >18 kWh per day. It's actually incredible how fast the tech has changed, when you look back!

jillesvangurp 3y ago
Some people actually saw this coming. The author fell in the trap of assuming nothing would change or improve. Which is interesting as a thought experiment but otherwise a bit flawed for making any kind of projections. There's a reason we have had so much progress in the last fifteen years: fifteen years ago, investments in this area had been ramping up for a while already. Those investors were making calculated bets on things improving massively. And they weren't wrong. There are some good reasons to continue to be optimistic about the next 27 years (until 2050). That's almost twice the amount of time since the original article from 2008. I expect grid storage is going to be massively successful as prices drop. There are a lot of different solutions emerging currently; many of which are not dependent on any scarce resources. Then learning effects applied to solar and wind should result in more cost reductions. Finally, industrial use of energy is likely to start changing as well. Industrial heating is a big topic with lots of possible solutions.
alextingle 3y ago
The book is about the UK, not the US. The UK has much, much less solar potential than the US. The southern most point of Great Britain is further north than the northern most point of the contiguous USA. And it's really, really rainy here too.
- owenversteeg 3y ago
  I'm very aware, I live on a boat in the Netherlands part of the year and it is off-grid, powered by solar :) You can generate a yearly average of 1.6 kWh per day in London from that single 550W panel, which is only 20% less than the 2 kWh per day I mentioned for the US. As I mentioned the panel is only $200 so if you need more power you can simply put up a few more. Also, obviously, there is a significant range depending on location in both the UK and the US: - in Yuma, AZ you will generate 3.19 kWh per year average (and the lowest, December is only 74% of peak in May!) - in Seattle, WA you will generate 1.95 kWh/day average (with winter 27% of peak) - in Oban, Scotland you will generate 1.35 kWh/day average (with winter 10% of peak) - in London you will generate 1.6 kWh/day average (with winter 17% of peak) The nice thing about solar, though, is that you can just overpanel for whatever your needs are. When the panels are so cheap, under $200 for a giant panel, you can just throw up some more panels and bam, you have enough solar year round. Obviously there are places far enough north to get too much darkness and snow to make year round solar realistic but even in most of the UK it is totally realistic to run off solar year round.

01100011 3y ago

Gonna need a lot of power to run all of the air conditioners that will be running in England soon. Spot electricity prices are going through the roof when the wind stops and the thermometer turns red. You'd think Europe would have already learned its lesson, with the collapse of German industry after losing cheap Russian energy. I guess they're betting they can move all the production to Morocco and other African countries and still survive as a functioning economy.

Guthur 3y ago

On a long enough timeline the answer to this is always no. If the question is can I burn something to release energy the answer is nearly always yes. If the question is can I depend on the weather for anything the answer is invariably eventually no.

adwf 3y ago

Biggest glaring problem for me is that they think it's somehow feasible to build on 7% of all land (for wind and solar combined). The current estimate of all land built on in the UK is only 8%, they think it's doable to nearly double that?

nl 3y ago
It's not "building on" in the "estimate of all land built on" sense. It's putting windfarms in existing agricultural land, where the farmland remains but has windmills in it too. [1] gives a range of around 5MW/km2 to 20MM/km2, which assuming 10MW turbines is roughly 1 turbine per square km. [1] https://web.stanford.edu/group/efmh/jacobson/Articles/I/WindSpacing.pdf https://web.stanford.edu/group/efmh/jacobson/Articles/I/Wind...
- adwf 3y ago
  Yes, but that's still kinda crazy. One turbine every square km means you'd never be out of sight of a turbine anywhere in the country... No unspoilt views, no hilly (therefore windy) landscape untarnished, etc.

asdefghyk 3y ago

Need to fund the needed storage . The storage capacity must be such that storage can supply through the times when no sun and no ( or minimal) wind. Could be several days. Present batteries are very expensive and need to be replaced every X years.

pfdietz 3y ago

I think MacKay also assumed a fairly large amount of biomass-derived fuel, which uses land very inefficiently.

IceHegel 3y ago

Perhaps I will go my whole life not understanding why nations didn't switch to nuclear fission. Covering 2% of the UK's land in solar panels seems very silly when we can just use the special rocks to boil water. But then again the UK is known for it's sunlight... oh wait

ngcc_hk 3y ago
It bite you later as where to put the rock after it was used. Obviously if it is all about economic as well as risk ... but it is not silly.
- pfdietz 3y ago
  This is not actually the reason nuclear failed. If we had a magic way to make nuclear waste just disappear forever, it would not materially change how much nuclear costs or how things turned out.
rsynnott 3y ago
The economics of nuclear are difficult; the cost is _extremely_ front loaded, moreso than virtually any other energy source. It's also awkwardly-sized; in practice, if you want to build a nuclear plant in Europe today, it's going to be in multiples of 1.7GWe and that is that (I think the EPR is literally the only plant currently licensed; there was also a GE one but it's basically vapourware). Not that it's impossible, and small numbers of nuclear plants are under construction (outside China, where the government is throwing money at the problem, and lots are) but it's far from the obvious route these days.
pfdietz 3y ago
The reason people didn't switch to nuclear fission was because it was too expensive. This is not hard to understand.

ngcc_hk 3y ago

I thought you need to have the wave/tide based generator as a more stable to compensate when solar and wind is lower down. It is not as efficient but predictable totally (as it is tide).

dm319 3y ago

This was genuinely enlightening to read, comments too.

bluenose69 3y ago

I don't see why the discussion centres on TWh, not TW. The former means something only when a time-frame is stated (per year, in this case). To avoid confusion, that interval ought to be stated in every phrase containing the unit. Which it isn't. This is needlessly confusing. It's not as though W is a confusing unit. Readers have an idea of the wattage of their lights, their stoves, their furnaces.

robin_reala 3y ago
Lights, maybe, but I doubt they do for their stoves. And “furnaces” (a en-US term which I guess is approximate to a gas boiler) are nearly always measured in terms of the units of gas they consume in the UK, not their power output.
rsynnott 3y ago
Unfortunately the ridiculous TWh/year metric is absolutely standard in the space, and it's far too late to do anything about it now.

physicsguy 3y ago

I read that book at the time, and what I rememember from it was that on top of the things discussed in the article here, there was a fairly lengthy section on peak demand and balancing that with renewables which are intermittent, which formed part of his conclusions.

audunw 3y ago
That discussion is probably even more out of date by now. I can’t imagine anyone would predict the scale of battery production happening today. That’s already starting to help with frequency regulation and short term balancing. Then there are the dozens of energy storage solutions designed specifically for grid energy storage which are in early commercial development right now. Ambri’s molten metal battery is one I like to use as an example.
- physicsguy 3y ago
  There's a long way to get there though - roughly adding ~0.5GW a year of battery storage in the UK and need ~40GW.
  - ZeroGravitas 3y ago
    National Grid just announced that 10GW of storage (and 10GW of renewables) that was already in their connection queue got fast-forwarded by 4 years. The technical innovation was to tell the projects "don't use the local grid if it is already at full capacity" rather than wait 4 years to upgrade the network to a gold plated standard for no good reason.

alextingle 3y ago

This article is extremely disingenuous about MacKay's "arguments against" section. In reality, he was pointing out the objections that might be raised against renewable projects, in a tongue-in-cheek manner. His graphic where >95% of potential renewables are crossed out because of various ridiculous NIMBY arguments is meant to make a point about the practical problems of delivering large projects. It's not a serious prediction... for that, you need to look later in the book, at the sections the author conveniently ignored.

stoobs 3y ago

We've already had numerous periods where the UK's energy needs have been wholly met from renewables, there's actually a very good site where you can see all the stats from the National Grid in near real-time - https://grid.iamkate.com https://grid.iamkate.com If you adjust the time range to all time (it has data for the last eleven or so years), where you can see the total demand dropping, and the renewables overtaking all of the other production sources. To be clear, there is still a decent demand to supply gap, but it is dropping year over year, and given that we've gone from an average of 2.5GW/day to between 10 and 13GW/day in that timeframe, another 20 years or so and we should start meeting demand with renewables alone. I'm hopeful that newer technology in that timeframe coupled with lower costs will encourage more and more generation growth from the sector, especially if more local generation and storage is encouraged, for example home solar/wind and home battery combinations. We'd also end up with a much more resilient power grid if most of the day to day needs can be met from local power systems, with the main grid only needing to supplement high stress periods and industrial and public communal requirements.

solumunus 3y ago
This is just electricity though right? A lot of (I assume most) homes in the UK are heated using gas.
- stoobs 3y ago
  Yes, but there's a huge push at the moment to move to heat-pumps which will remove the need for natural gas for home heating. I did hear that there were also trials to shift from natural gas to either straight hydrogen, or a hydrogen/natural gas mix - but according to the people I had a conversation with, much of the infrastructure will need upgrading as well as all the gas engineers/plumbers needing retraining, given that hydrogen is much harder to keep contained due to the tiny size of the H2 molecule vs that of natural gas (mostly methane), as well as it burning differently so needing different internals for heating systems. Answer is still roughly the same though, give it another 10 years or so and re-evaluate
- ben_w 3y ago
  Yes to just electricity, I think so for gas heating (I've also been in places in the UK with open hearth wood fires, oil heating, solar thermal, and pure electric, and that's just where I knew the heat source). Assuming the linked calculations are correct, this doesn't matter because all current power consumption can be electrified. Of course, even that's still not sufficient, as the chemical byproducts of several major agricultural and industrial processes also produce greenhouse gases. Fortunately, people are working on those too.