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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

by 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.
- gpm 3y ago
  The ballpark number for EVs is that they are 4x more efficient than ICE cars AIUI. Harder to ball park heat pumps because it depends on the climate, but 4x is probably a reasonable guesstimate. At worse it's equal to burning things for heating (when it's too cold outside to use heat pumps, not sure that really happens in Britain), at best it's... some ridiculous factor better (when it's practically the same temperature outside and inside).
  - mschuster91 3y ago
    [dead]
raphaelj 3y ago
From what I understand, these TWhs refer to total energy usage, not electricity usage. If you replace a ICE by an BEV powered by solar cells, you actually reduce the total TWhs because of efficiecy: - ICE: 6L of gasoline per 100km, that equals to about 60 KWh - BEV: 17KWh for the same distance. The same applies to heat-pumps and some industrial processes.
- conjecTech 3y ago
  Correct, a lot of Mackay's estimates fail to account for the difference in delivered efficiency between electric solutions and their gas counterparts. For instance in his car section[1], he estimate you'd need to produce 40kwh to drive 50km. That may be close to the true energetic content of the gas burned, but you could drive that far on just 10kwh in a modern EV, meaning electrification dropped your gross energy needs by 75%. [1] https://www.withouthotair.com/c3/page_29.shtml https://www.withouthotair.com/c3/page_29.shtml
  - ZeroGravitas 3y ago
    He was aware of the benefits of EVs though, from a later chapter > OK, the race is over, and I’ve announced two winners – public transport, and electric vehicles. He was also very positive about heat pumps. https://www.withouthotair.com/c20/page_131.shtml https://www.withouthotair.com/c20/page_131.shtml > You’ve shown that electric cars are more energy-efficient than fossil cars. But are they better if our objective is to reduce CO2 emissions, and the electricity is still generated by fossil power- stations? > This is quite an easy calculation to do. Assume the electric vehicle’s energy cost is 20 kWh(e) per 100 km. (I think 15 kWh(e) per 100 km is perfectly possible, but let’s play sceptical in this calculation.) If grid electricity has a carbon footprint of 500 g per kWh(e) then the effective emissions of this vehicle are 100 g CO2 per km, which is as good as the best fossil cars (figure 20.9). So I conclude that switching to electric cars is already a good idea, even before we green our electricity supply.
    - lostlogin 3y ago
      And that misses the petrol station thing. Stocking the station tanks (and that supply chain), staffing, etc, that doesn’t cost zero.
cpncrunch 3y ago
I think youve misread it. 1600TWh is the demand today. The 2900 figure is potential supply of wind and solar.
- lucb1e 3y ago
  Could you cite where you found those numbers? I can't find either of them: The submission (blog post) doesn't mention the number 900 at all; the paper which the submission is about only mentions 900 in a footnote saying "Total European [energy] supply was 22,900 TWh (IEA, 2022)."; the summary pdf of said paper never mentions 900 or 600. Figures in the paper ending in 600 occur in a few spots, but nowhere 1600. There is 21'600 TWh/year (total European energy supply, page 8), 16'600 TWh/year (idem), 10'600 TWh/year (prior studies' estimates of UK wind resources), and 2'600 km² (land occupied by buildings). But maybe I shouldn't be drawing conclusions based on trying to search character sequences in a semi-picture format...
  - hwillis 3y ago
    > They estimate that it could produce 2,895 TWh of electricity each year from solar and wind. That’s almost double its estimate for final energy demand in 2050. See the chart below. [...] We can see this when we look at other estimates of energy demand from the literature. The National Grid FES projects that Britain will need just 900 TWh in 2050. [...] Total final energy demand today is 1599 TWh. It's right under the first main heading. Just above and below the first picture. Searching for 900 in the post took me right to it. I have no idea how you missed it.
    - deleted 3y ago
      [deleted]
marcosdumay 3y ago
Electrification doesn't cause such a decrease. Fixing your projection so it's not anymore a "we can't do anything, we must keep investing in BP" piece into a realistic one is what reduces it. Honestly, anybody claiming in 2008 that PVs are too expensive so we should not invest on them is safe to ignore.
- Gibbon1 3y ago
  That's close to the time frame when I realized solar was going to win just based on pure business accounting. Thing to consider the ultimate price of a manufactured good tends to track production volume, device complexity, and energy required to produce including raw material. Solar panels require complex machines to produce but are themselves simple, the volume is high at scale, and energy requirements are low. That points to something where the price is close to the energy and material costs.
  - marcosdumay 3y ago
    > energy requirements are low They can surely become low, but currently they are not. The EROEI of PV panels is barely on the region where it stops being one of the largest factors in its cost. But yeah, PV has space to improve a by a few orders of magnitude more.
- specialist 3y ago
  > claiming in 2008 that PVs are too expensive You're misrepresenting the analysis. In the 15 years since, public support for PV flipped from con to pro, and we've learned that much less land must be allocated to just PV. As noted in the OC, Mackay's contribution was methodological. It easily accommodates different assumptions and updated numbers. O'Callaghan et al did just that. Yielding a new conclusion.
acdha 3y ago
I could believe some reduction if there were massive efficiency increases (e.g. replacing resistive heating with heat pumps) but that seems impossible on that scale unless they’re also forecasting entire industries leaving the country.
ViewTrick1002 3y ago
Take a look at the amount of rejected energy we waste by using for example heat engines today. Electrical engines and heat pumps vastly reduce those losses. https://flowcharts.llnl.gov/ https://flowcharts.llnl.gov/
greenthrow 3y ago
ICE vehicles turn less than 35% of their energy consumption into productive work. The rest is waste heat. That's the main reason transitioning to pure EVs must happen.
- PeterisP 3y ago
  That's an inherent limitation of heat engines - if you burn the same thing in a power plant, then you could get 45% instead of 35%, but you can't possibly convert, say, 80% of burned fossil fuel into productive work.
  - danans 3y ago
    > if you burn the same thing in a power plant, then you could get 45% instead of 35%, but you can't possibly convert, say, 80% of burned fossil fuel into productive work. Not 80%, but combined cycle gas turbines regularly achieve up to 60% steady state efficiency. There is research into ammonia fueled turbines that supposedly achieve even higher efficiency.
    - robotresearcher 3y ago
      And Combined Heat and Power plants get up to 75% by using some of the heat.
- cm2187 3y ago
  I really don’t see the point of that calculation. It’s like saying that the wind turbine only captures 5% (number made up) of the energy of the wind going through it.
  - robotresearcher 3y ago
    If you had to pay for the wind you might be very interested in that ratio.
    - cm2187 3y ago
s1artibartfast 3y ago
IT looks like the 900 number is discussed in chapter 3 of this document [1]. As far as I can tell the current usage of 1200 TWh include electricity and combustible chimerical energy of gas. Electricity use is ~300 Twh, and Gas usage is ~800 Twh. The proposal is that gas heating would be entirely replaced with heat pumps and most gas generation would be replaced with modular nuclear reactors and offshore wind. The numbers are a little misleading because of the way gas and electricity are summed to get the top level numbers. A TWh of gas consumption is not the same as a TWh of electricity consumption. In thier model, 50 TWh of electricity can replace 400 TWh of gas. The challenge with this approach is that it is not show what is going on with user consumption. Are they getting more, less, or the same thermodynamic work done? https://www.nationalgrid.com/document/138976/download#:~:text=%E2%88%8E%20Electricity%20peak%20demand%20could,as%20nine%20million%20by%202030 https://www.nationalgrid.com/document/138976/download#:~:tex....
vlovich123 3y ago
I would bet that electricity demand goes up, not down. When a good becomes cheaper/more efficient, demand increases.
- hwillis 3y ago
  1. They're talking about all energy (cars, heat, and electricity), not just electricity. 2. Demand is up in this scenario, not supply, because of all the things being electrified.
- bluGill 3y ago
  But the change is not a 1:1 linear ratio. Demand increases, but only if there is pain that more could use. Once a room is bright enough you won't add more light.
  - vlovich123 3y ago
    Sure, but you may not be as diligent turning off the lights.
    - bluGill 3y ago
      Exactly, but the improved efficiency is more than the loss from leaving it on.
      - vlovich123 3y ago
        > Exactly, but the improved efficiency is more than the loss from leaving it on. The improved efficiency needs to be more than the drop in marginal cost which is what governs demand, nothing to do with how much more electricity you use today. And even then, that relationship isn't linear because a 30% reduction in cost can drive a 60% increase in demand because that reduction puts it in a new price bracket where a lot more people can afford it (since wealth is non-linear). This stuff is super non trivial and has all sorts of higher order effects.
        3y ago
cycomanic 3y ago
There is no such projection, it seems you misread something. The O’Callaghan et al. paper (in the Blog post here the related figure is fig 1) says that current (2023) demand is 1500TWh and current supply is 2885 TWh. There are different projections for total demand in 2050 (note all of them project a reduction of demand, due to efficiency gains), one of these is the national grid FES which projects 900 TWh. Importantly the O'Callaghan paper opts to be conservative and choose to use the current demand as the demand for 2050. This is conservative, because it is higher than all projections which all assume that we get demand reduction from efficiency gains.
cycomanic 3y ago
I want to add that Britain's energy demand has already fallen by one quarter in the last 15 years even without the efficiency gains from large scale electrification, so a 2/3 reduction (which to stress again is not what the paper assumes) is not so outrageous.
- nradov 3y ago
  Some of that is due to efficiency gains (good). But some is also due to deindustrialization and increased imports of energy intensive products (bad). We have to look at full lifecycle global CO2 emissions in order to perform a valid analysis of any changes.
  - ben_w 3y ago
    Depends what you care about. MacKay's claim was specifically that the UK couldn't be powered this way (which appears to be falsified); if the manufacturing all ends up in China, which has the Gobi desert and is closer to the equator, and has the Three Gorges Dam and the will to build it, I don't even have to run the numbers to know they can be completely green.
    - nradov 3y ago
      China isn't even remotely "green". Most of the official statistics coming out of there are highly manipulated. In particular they haven't built even a fraction of the storage capacity that would be needed to keep their factories running when the sun isn't shining, nor are they likely to do so in the next few decades.
      - nl 3y ago
        China is building multiple 1000km+ HVAC transmission lines which gives climatic diversity (and power source diversity: wind, solar and three gorges). That removes the need for storage (and is what every other country should be doing as well).
      - ben_w 3y ago
snapplebobapple 3y ago
The better question is why do they think more efficiency will lead to lower use rather than higher consumption? I know, if the price stays the same per unit of energy and i stop spendjng so much because of efficiency gains, i have a ton of other stuff i would love to do that consumes energy so my decrease in usage would be tiny. What will decrease my usage is price increases, which can only go so far as taxes to capture proposed externalities before i revolt and elect someone who will axe the tax (as is about to happen in canada).
- bobthepanda 3y ago
  Energy use per capita has already been falling for two decades in the US: https://www.npr.org/sections/money/2013/04/10/176801719/two-centuries-of-energy-in-america-in-four-graphs https://www.npr.org/sections/money/2013/04/10/176801719/two-...
  - snapplebobapple 3y ago
    Thats not really what that chart looks like to me, or at least the effect is very moderate. The big drops correspond to economic shocks. Even if i ignore that the chart is topping at roughly 350 in 1975 and bottoming around 310 in what i assume is 2023, which makes it what? A 0.22% annual decrease?
  - kjkjadksj 3y ago
    You are making the assumption there won’t be some new technology that gobbles up significant energy. At one point an American’s electrical consumption might have been home lighting and a radio. Then it jumped by an order of magnitude with the refrigerator and air conditioner.
    - pfdietz 3y ago
      Most of the examples I can think of with that would not be localized. For example, if we need massively more computing for an AI breakthrough, there's nothing requiring that to be localized. Similarly for production of any commodity that can be shipped.
onthecanposting 3y ago
[flagged]
- Zacharias030 3y ago
  This deserves to be flagged. Steep insinuating claims without any credible sources or arguments. @dang US life expectancy is declining unfortunately, but for unrelated reasons.
- Retric 3y ago
  That’s got nothing to do with these total energy calculations. When burning gas in a car you’re converting less than 1/5th of the energy in the crude oil to actually move your car. A wind powered EV is closer to 4/5th of the energy from wind ending up moving your car. Not only is the EV itself more efficient, so is each stage before that more efficient. Something like 1/3 to 1/2 of all CO2 emissions from ICE cars occur before gasoline makes it to the car. Thus, driving an EV lowers the total energy needed without actually reducing how much people are driving. PS: Total energy calculations are fairly arbitrary because it’s ultimately sunlight powering things, but that’s also true of fossil fuels just at really unbelievably low efficiency so that parts generally ignored.
- s_tec 3y ago
  Please explain. I keep hearing this meme, but the arguments don't make sense. For instance, people will say things like, "New World Order wants us all to use electric vehicles so they can limit our movement!" This is backwards, though, because electric cars can plug in anywhere, but gasoline stations are much more centralized and easy to regulate. If I were the Global Elite, I wouldn't want people producing power on their own rooftops, storing it in batteries, and driving around with it. Green technologies seem to lower costs and increase resilience for the average person. What am I missing?
Johnythree 3y ago
In the past, customers were encouraged to be very inefficient with their electricity usage. Rather than fit efficient insulation, high consumption was tolerated for years to come. And thanks to the "Base Load" myth of coal based generators, people were encouraged to use heat banks and storage HWS which loaded the system during the night. But this could only be done by offering cheap "night rate" electricity. In the future, our consumption must be focused on day-time peaks, as well as much better insulation, and the use of heat-pumps. And of course a steep increase in electricity tariffs will greatly encourage this. In the future, companies which operate 24 Hrs without thought to electrical cost, will focus much more on efficiency, and even begin to shut down operations at night. In many countries (eg Australia) there has already been a huge increase in domestic solar and battery installations. This change will be driven by unavoidable price rises, and the recognition of our profligate wastage in the past..
thelastgallon 3y ago
Burning fuel to generate electricity creates waste heat that siphons off most of the energy. By the time electricity reaches your outlet, around two-thirds of the original energy has been lost in the process: https://yaleclimateconnections.org/2022/10/energy-loss-is-single-biggest-component-of-todays-electricity-system https://yaleclimateconnections.org/2022/10/energy-loss-is-si... With Solar and Wind, there isn't any wasted heat.
nl 3y ago
> the projection of overall energy demand to shrink from 2900 TWh to 900 TWh over the next 27 years To be clear, today's demand isn't 2900 TWh. It's 1599 TWh. And none of the people claiming Britain can be powered via renewable power are using the 900 TWh figure. Just noting for people who haven't read the article because this comment wasn't clear to me: Today's demand: 1599 TWh UK’s Department for Industrial Strategy forecast demand for 2050: 1250 TWh UK National Grid FES forecast demand for 2050: 900 TWh MacKay’s forecast demand for 2050: 2900 TWh (I think this is what this comment is referring to) MacKay’s 2008 forecast renewable production for 2050: 1500 TWh O’Callaghan (new, 2023 report) forecast demand for 2050: 1500 TWh O’Callaghan (new, 2023 report) forecast renewable production for 2050: 2895 TWh The difference is mostly about pricing of renewables radically dropping since 2008, and the likelihood of floating offshore wind producing large amounts of supply. [1] https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu...
navneeraj 3y ago
She explains it here in this post https://www.sustainabilitybynumbers.com/p/electrification-energy-efficiency https://www.sustainabilitybynumbers.com/p/electrification-en.... Many comments try to allude to it. It is important what we are talking about- Primary energy, Secondary energy, Final energy or the Useful energy. The embedded links go in further details.
benj111 3y ago
Electricity demand has fallen by ~10% over the past decade while we've been introducing EVs and heat pumps and stuff. These things are all more efficient than the hydrocarbon equivalents, further depending on the measure, if you count the gas input energy in to a gas plant, a renewable generator is much more efficient too. So I think it's possible, although the figure ends up somewhat misleading without a lot of context.

by Doches 3y ago

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.
gpm 3y ago
The ballpark number for EVs is that they are 4x more efficient than ICE cars AIUI. Harder to ball park heat pumps because it depends on the climate, but 4x is probably a reasonable guesstimate. At worse it's equal to burning things for heating (when it's too cold outside to use heat pumps, not sure that really happens in Britain), at best it's... some ridiculous factor better (when it's practically the same temperature outside and inside).
- mschuster91 3y ago
  [dead]

raphaelj 3y ago

From what I understand, these TWhs refer to total energy usage, not electricity usage. If you replace a ICE by an BEV powered by solar cells, you actually reduce the total TWhs because of efficiecy: - ICE: 6L of gasoline per 100km, that equals to about 60 KWh - BEV: 17KWh for the same distance. The same applies to heat-pumps and some industrial processes.

conjecTech 3y ago
Correct, a lot of Mackay's estimates fail to account for the difference in delivered efficiency between electric solutions and their gas counterparts. For instance in his car section[1], he estimate you'd need to produce 40kwh to drive 50km. That may be close to the true energetic content of the gas burned, but you could drive that far on just 10kwh in a modern EV, meaning electrification dropped your gross energy needs by 75%. [1] https://www.withouthotair.com/c3/page_29.shtml https://www.withouthotair.com/c3/page_29.shtml
- ZeroGravitas 3y ago
  He was aware of the benefits of EVs though, from a later chapter > OK, the race is over, and I’ve announced two winners – public transport, and electric vehicles. He was also very positive about heat pumps. https://www.withouthotair.com/c20/page_131.shtml https://www.withouthotair.com/c20/page_131.shtml > You’ve shown that electric cars are more energy-efficient than fossil cars. But are they better if our objective is to reduce CO2 emissions, and the electricity is still generated by fossil power- stations? > This is quite an easy calculation to do. Assume the electric vehicle’s energy cost is 20 kWh(e) per 100 km. (I think 15 kWh(e) per 100 km is perfectly possible, but let’s play sceptical in this calculation.) If grid electricity has a carbon footprint of 500 g per kWh(e) then the effective emissions of this vehicle are 100 g CO2 per km, which is as good as the best fossil cars (figure 20.9). So I conclude that switching to electric cars is already a good idea, even before we green our electricity supply.
  - lostlogin 3y ago
    And that misses the petrol station thing. Stocking the station tanks (and that supply chain), staffing, etc, that doesn’t cost zero.

cpncrunch 3y ago

I think youve misread it. 1600TWh is the demand today. The 2900 figure is potential supply of wind and solar.

lucb1e 3y ago
Could you cite where you found those numbers? I can't find either of them: The submission (blog post) doesn't mention the number 900 at all; the paper which the submission is about only mentions 900 in a footnote saying "Total European [energy] supply was 22,900 TWh (IEA, 2022)."; the summary pdf of said paper never mentions 900 or 600. Figures in the paper ending in 600 occur in a few spots, but nowhere 1600. There is 21'600 TWh/year (total European energy supply, page 8), 16'600 TWh/year (idem), 10'600 TWh/year (prior studies' estimates of UK wind resources), and 2'600 km² (land occupied by buildings). But maybe I shouldn't be drawing conclusions based on trying to search character sequences in a semi-picture format...
- hwillis 3y ago
  > They estimate that it could produce 2,895 TWh of electricity each year from solar and wind. That’s almost double its estimate for final energy demand in 2050. See the chart below. [...] We can see this when we look at other estimates of energy demand from the literature. The National Grid FES projects that Britain will need just 900 TWh in 2050. [...] Total final energy demand today is 1599 TWh. It's right under the first main heading. Just above and below the first picture. Searching for 900 in the post took me right to it. I have no idea how you missed it.
  - deleted 3y ago
    [deleted]

marcosdumay 3y ago

Electrification doesn't cause such a decrease. Fixing your projection so it's not anymore a "we can't do anything, we must keep investing in BP" piece into a realistic one is what reduces it. Honestly, anybody claiming in 2008 that PVs are too expensive so we should not invest on them is safe to ignore.

Gibbon1 3y ago
That's close to the time frame when I realized solar was going to win just based on pure business accounting. Thing to consider the ultimate price of a manufactured good tends to track production volume, device complexity, and energy required to produce including raw material. Solar panels require complex machines to produce but are themselves simple, the volume is high at scale, and energy requirements are low. That points to something where the price is close to the energy and material costs.
- marcosdumay 3y ago
  > energy requirements are low They can surely become low, but currently they are not. The EROEI of PV panels is barely on the region where it stops being one of the largest factors in its cost. But yeah, PV has space to improve a by a few orders of magnitude more.
specialist 3y ago
> claiming in 2008 that PVs are too expensive You're misrepresenting the analysis. In the 15 years since, public support for PV flipped from con to pro, and we've learned that much less land must be allocated to just PV. As noted in the OC, Mackay's contribution was methodological. It easily accommodates different assumptions and updated numbers. O'Callaghan et al did just that. Yielding a new conclusion.

acdha 3y ago

I could believe some reduction if there were massive efficiency increases (e.g. replacing resistive heating with heat pumps) but that seems impossible on that scale unless they’re also forecasting entire industries leaving the country.

ViewTrick1002 3y ago

Take a look at the amount of rejected energy we waste by using for example heat engines today. Electrical engines and heat pumps vastly reduce those losses. https://flowcharts.llnl.gov/ https://flowcharts.llnl.gov/

greenthrow 3y ago

ICE vehicles turn less than 35% of their energy consumption into productive work. The rest is waste heat. That's the main reason transitioning to pure EVs must happen.

PeterisP 3y ago
That's an inherent limitation of heat engines - if you burn the same thing in a power plant, then you could get 45% instead of 35%, but you can't possibly convert, say, 80% of burned fossil fuel into productive work.
- danans 3y ago
  > if you burn the same thing in a power plant, then you could get 45% instead of 35%, but you can't possibly convert, say, 80% of burned fossil fuel into productive work. Not 80%, but combined cycle gas turbines regularly achieve up to 60% steady state efficiency. There is research into ammonia fueled turbines that supposedly achieve even higher efficiency.
  - robotresearcher 3y ago
    And Combined Heat and Power plants get up to 75% by using some of the heat.
cm2187 3y ago
I really don’t see the point of that calculation. It’s like saying that the wind turbine only captures 5% (number made up) of the energy of the wind going through it.
- robotresearcher 3y ago
  If you had to pay for the wind you might be very interested in that ratio.
  - cm2187 3y ago

s1artibartfast 3y ago

IT looks like the 900 number is discussed in chapter 3 of this document [1]. As far as I can tell the current usage of 1200 TWh include electricity and combustible chimerical energy of gas. Electricity use is ~300 Twh, and Gas usage is ~800 Twh. The proposal is that gas heating would be entirely replaced with heat pumps and most gas generation would be replaced with modular nuclear reactors and offshore wind. The numbers are a little misleading because of the way gas and electricity are summed to get the top level numbers. A TWh of gas consumption is not the same as a TWh of electricity consumption. In thier model, 50 TWh of electricity can replace 400 TWh of gas. The challenge with this approach is that it is not show what is going on with user consumption. Are they getting more, less, or the same thermodynamic work done? https://www.nationalgrid.com/document/138976/download#:~:text=%E2%88%8E%20Electricity%20peak%20demand%20could,as%20nine%20million%20by%202030 https://www.nationalgrid.com/document/138976/download#:~:tex....

vlovich123 3y ago

I would bet that electricity demand goes up, not down. When a good becomes cheaper/more efficient, demand increases.

hwillis 3y ago
1. They're talking about all energy (cars, heat, and electricity), not just electricity. 2. Demand is up in this scenario, not supply, because of all the things being electrified.
bluGill 3y ago
But the change is not a 1:1 linear ratio. Demand increases, but only if there is pain that more could use. Once a room is bright enough you won't add more light.
- vlovich123 3y ago
  Sure, but you may not be as diligent turning off the lights.
  - bluGill 3y ago
    Exactly, but the improved efficiency is more than the loss from leaving it on.
    - vlovich123 3y ago
      > Exactly, but the improved efficiency is more than the loss from leaving it on. The improved efficiency needs to be more than the drop in marginal cost which is what governs demand, nothing to do with how much more electricity you use today. And even then, that relationship isn't linear because a 30% reduction in cost can drive a 60% increase in demand because that reduction puts it in a new price bracket where a lot more people can afford it (since wealth is non-linear). This stuff is super non trivial and has all sorts of higher order effects.
      - 3y ago

cycomanic 3y ago

There is no such projection, it seems you misread something. The O’Callaghan et al. paper (in the Blog post here the related figure is fig 1) says that current (2023) demand is 1500TWh and current supply is 2885 TWh. There are different projections for total demand in 2050 (note all of them project a reduction of demand, due to efficiency gains), one of these is the national grid FES which projects 900 TWh. Importantly the O'Callaghan paper opts to be conservative and choose to use the current demand as the demand for 2050. This is conservative, because it is higher than all projections which all assume that we get demand reduction from efficiency gains.

cycomanic 3y ago

I want to add that Britain's energy demand has already fallen by one quarter in the last 15 years even without the efficiency gains from large scale electrification, so a 2/3 reduction (which to stress again is not what the paper assumes) is not so outrageous.

nradov 3y ago
Some of that is due to efficiency gains (good). But some is also due to deindustrialization and increased imports of energy intensive products (bad). We have to look at full lifecycle global CO2 emissions in order to perform a valid analysis of any changes.
- ben_w 3y ago
  Depends what you care about. MacKay's claim was specifically that the UK couldn't be powered this way (which appears to be falsified); if the manufacturing all ends up in China, which has the Gobi desert and is closer to the equator, and has the Three Gorges Dam and the will to build it, I don't even have to run the numbers to know they can be completely green.
  - nradov 3y ago
    China isn't even remotely "green". Most of the official statistics coming out of there are highly manipulated. In particular they haven't built even a fraction of the storage capacity that would be needed to keep their factories running when the sun isn't shining, nor are they likely to do so in the next few decades.
    - nl 3y ago
      China is building multiple 1000km+ HVAC transmission lines which gives climatic diversity (and power source diversity: wind, solar and three gorges). That removes the need for storage (and is what every other country should be doing as well).
    - ben_w 3y ago

snapplebobapple 3y ago

The better question is why do they think more efficiency will lead to lower use rather than higher consumption? I know, if the price stays the same per unit of energy and i stop spendjng so much because of efficiency gains, i have a ton of other stuff i would love to do that consumes energy so my decrease in usage would be tiny. What will decrease my usage is price increases, which can only go so far as taxes to capture proposed externalities before i revolt and elect someone who will axe the tax (as is about to happen in canada).

bobthepanda 3y ago
Energy use per capita has already been falling for two decades in the US: https://www.npr.org/sections/money/2013/04/10/176801719/two-centuries-of-energy-in-america-in-four-graphs https://www.npr.org/sections/money/2013/04/10/176801719/two-...
- snapplebobapple 3y ago
  Thats not really what that chart looks like to me, or at least the effect is very moderate. The big drops correspond to economic shocks. Even if i ignore that the chart is topping at roughly 350 in 1975 and bottoming around 310 in what i assume is 2023, which makes it what? A 0.22% annual decrease?
- kjkjadksj 3y ago
  You are making the assumption there won’t be some new technology that gobbles up significant energy. At one point an American’s electrical consumption might have been home lighting and a radio. Then it jumped by an order of magnitude with the refrigerator and air conditioner.
  - pfdietz 3y ago
    Most of the examples I can think of with that would not be localized. For example, if we need massively more computing for an AI breakthrough, there's nothing requiring that to be localized. Similarly for production of any commodity that can be shipped.

onthecanposting 3y ago

[flagged]

Zacharias030 3y ago
This deserves to be flagged. Steep insinuating claims without any credible sources or arguments. @dang US life expectancy is declining unfortunately, but for unrelated reasons.
Retric 3y ago
That’s got nothing to do with these total energy calculations. When burning gas in a car you’re converting less than 1/5th of the energy in the crude oil to actually move your car. A wind powered EV is closer to 4/5th of the energy from wind ending up moving your car. Not only is the EV itself more efficient, so is each stage before that more efficient. Something like 1/3 to 1/2 of all CO2 emissions from ICE cars occur before gasoline makes it to the car. Thus, driving an EV lowers the total energy needed without actually reducing how much people are driving. PS: Total energy calculations are fairly arbitrary because it’s ultimately sunlight powering things, but that’s also true of fossil fuels just at really unbelievably low efficiency so that parts generally ignored.
s_tec 3y ago
Please explain. I keep hearing this meme, but the arguments don't make sense. For instance, people will say things like, "New World Order wants us all to use electric vehicles so they can limit our movement!" This is backwards, though, because electric cars can plug in anywhere, but gasoline stations are much more centralized and easy to regulate. If I were the Global Elite, I wouldn't want people producing power on their own rooftops, storing it in batteries, and driving around with it. Green technologies seem to lower costs and increase resilience for the average person. What am I missing?

Johnythree 3y ago

In the past, customers were encouraged to be very inefficient with their electricity usage. Rather than fit efficient insulation, high consumption was tolerated for years to come. And thanks to the "Base Load" myth of coal based generators, people were encouraged to use heat banks and storage HWS which loaded the system during the night. But this could only be done by offering cheap "night rate" electricity. In the future, our consumption must be focused on day-time peaks, as well as much better insulation, and the use of heat-pumps. And of course a steep increase in electricity tariffs will greatly encourage this. In the future, companies which operate 24 Hrs without thought to electrical cost, will focus much more on efficiency, and even begin to shut down operations at night. In many countries (eg Australia) there has already been a huge increase in domestic solar and battery installations. This change will be driven by unavoidable price rises, and the recognition of our profligate wastage in the past..

thelastgallon 3y ago

Burning fuel to generate electricity creates waste heat that siphons off most of the energy. By the time electricity reaches your outlet, around two-thirds of the original energy has been lost in the process: https://yaleclimateconnections.org/2022/10/energy-loss-is-single-biggest-component-of-todays-electricity-system https://yaleclimateconnections.org/2022/10/energy-loss-is-si... With Solar and Wind, there isn't any wasted heat.

nl 3y ago

> the projection of overall energy demand to shrink from 2900 TWh to 900 TWh over the next 27 years To be clear, today's demand isn't 2900 TWh. It's 1599 TWh. And none of the people claiming Britain can be powered via renewable power are using the 900 TWh figure. Just noting for people who haven't read the article because this comment wasn't clear to me: Today's demand: 1599 TWh UK’s Department for Industrial Strategy forecast demand for 2050: 1250 TWh UK National Grid FES forecast demand for 2050: 900 TWh MacKay’s forecast demand for 2050: 2900 TWh (I think this is what this comment is referring to) MacKay’s 2008 forecast renewable production for 2050: 1500 TWh O’Callaghan (new, 2023 report) forecast demand for 2050: 1500 TWh O’Callaghan (new, 2023 report) forecast renewable production for 2050: 2895 TWh The difference is mostly about pricing of renewables radically dropping since 2008, and the likelihood of floating offshore wind producing large amounts of supply. [1] https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu...

navneeraj 3y ago

She explains it here in this post https://www.sustainabilitybynumbers.com/p/electrification-energy-efficiency https://www.sustainabilitybynumbers.com/p/electrification-en.... Many comments try to allude to it. It is important what we are talking about- Primary energy, Secondary energy, Final energy or the Useful energy. The embedded links go in further details.

benj111 3y ago

Electricity demand has fallen by ~10% over the past decade while we've been introducing EVs and heat pumps and stuff. These things are all more efficient than the hydrocarbon equivalents, further depending on the measure, if you count the gas input energy in to a gas plant, a renewable generator is much more efficient too. So I think it's possible, although the figure ends up somewhat misleading without a lot of context.