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Grid storage is such an interesting topic to me. We are all used to energy storage at a small scale (phone batteries, even electric cars) but the challenges of

• IAmEveryone 6y ago
  Electric cars are perfect for this. Connect them to the grid and the internet, and they’ll charge but also feed back as needed.
  • eldaisfish 6y ago
    Have you heard of Tesla's batter in south Australia? It was recently expanded to 193 MWh. Care to guess how long it'll run at full power? Around 60-100 minutes. At its rated power of 100 MW, it can power around 25% of South Australia's lowest demand. That's it. At peak demand, the fraction is lower still. Cars have a fraction of the energy storage capacity of a single battery site and not all cars are connected to the grid at all times and neither will all their stored energy be usable. Batteries aren't the silver bullet many imaging them to be. The real solution is expanding transmission capacity, building more renewables and supplementing that by nuclear or hydro.
    • lightgreen 6y ago
      For the comparison, average nuclear power plant produces 1000MW around the clock. The goal of Australia batteries was to normalize short production/consumption fluctuations, not as general universal battery storage to deal with renewable uneven production.
      • eldaisfish 6y ago
        My point was simply to illustrate that batteries are not a viable energy storage method for the scale of energy required on even a small power grid. South Australia's power grid is relatively small compared to many similar regions.
    • missedthecue 6y ago
      I don't know if there's enough lithium in the world to stabilize a global renewable grid and make 100 million electric cars per year forever and make 1.5 billion phones a year and all the other things we use batteries for.
      • bluGill 6y ago
        Hopefully we start to recycle batteries better. Most people throw their old broken phone in a landfill from what I gather. (broken, there is a market for non-broken phones)
      • kwhitefoot 6y ago
        Lithium is very abundant. It's the 25th most abundant element at about 20 mg per kg in the Earth's crust. It is present in seawater at a concentration of about 0.2 ppm in seawater, about 230 billion tons total. If electricity is going to be so cheap then we can just extract lithium from seawater. Plus dead lithium batteries can of course be used as a high grade ore. See https://en.wikipedia.org/wiki/Lithium https://en.wikipedia.org/wiki/Lithium
    • kalleboo 6y ago
      25% of lowest demand sounds amazing! I'm mostly a pessimist about renewables due to the storage issue so I would have guessed more like 2-5%. Assuming lowest demand is at night, that means that building just 3 more batteries you could power the whole state for an hour at night?
      • bluefirebrand 6y ago
        Agree, I'm missing some context to see why your parent post thought this was good enough. I suspect that "Lowest Demand" is being thought of in two different ways.
        • eldaisfish 6y ago
          even at the lowest demand, a large, grid-connected battery can only provide minutes of back up power, and that too for only a fraction of already low demand. A storage battery is not a viable means of balancing demand and supply over a time period longer than minutes. What's needed is not more batteries but better transmission, more hydro where possible and where hydro is not possible, more nuclear.
          • bluefirebrand 6y ago
            When you're talking about lowest demand are you talking about for the whole grid? A city block? A building? A condo? And I agree. I worked in solar and storage for a while. It's not a replacement, it's just an extension. It works out ok for a battery system for a building but anything larger they just don't last long enough
            • eldaisfish 6y ago
              Only the south australian grid, which is not a relatively large grid. South Australia's population is small, under two million and it's demand fluctuates between 400 - 3000 MW. For comparison, the Canadian province of New Brunswick has a comparable peak demand but fewer than a million people.
  • ppf 6y ago
    That's not ideal, as it would eat through the battery's cycle life at a much quicker rate.
  • aclelland 6y ago
    I've seen this suggested often but I don't think I've ever seen any information about how it'd actually work in practise. Do the car companies actually want to do it, how is the car owner compensated for the battery wear and tear and who'd be in control of the management (government regulators, energy companies, car manufacturers). Are there any examples of pilot schemes that have used cars in this way?
    • martinald 6y ago
      It isn't the silver bullet some people say it is. Firstly, as others mentioned it really hammers the battery life. Secondly, it requires cars not being full so they can be topped up, which means less range. Not to mention I don't think the local grid to houses can support loads of cars suddenly getting charged at once, which is what you want for big wind spikes.
      • pydry 6y ago
        You could at least program the cars to adjust their charging based upon cost - e.g. if you leave it overnight and between 2-5am electricity prices go negative it could try to charge most of the battery during this period. Additionally you could program cars to feed into the grid when the price goes high enough to justify the cost of cycling the battery. This would help deal with unexpected events.
        • bluecookeh93 6y ago
          Yeah it's very much a niche but it's possible to buy chargers that integrate with Octopus Agile and do exactly that in the UK. Alternatively some of us are doing it with automations in apps like Home Assistant.
    • kwhitefoot 6y ago
      Nissan and Hyundai already produce cars with vehicle to grid (Nissan) and vehicle to load (Hyundai).
  • VBprogrammer 6y ago
    IMO recycling batteries after use in cars is a more interesting idea. A 20% reduction in a cars range is significant but not an issue in actual power storage.
  • giobox 6y ago
    As an electric car owner, do I want to give my limited lithium battery charge cycle lifespan back to the network? This storage isn't "free" to the vehicle owner - charging and feeding back will contribute to the total charge cycles on your very expensive battery pack, which of course reduces range over time. I'd need to be heavily convinced by the economic arguments outweighing the wear on a very expensive vehicle component before I'd consider this. When you come to resell an electric car, the condition of the battery is going to be significant in resale value too. There would presumably be a zip code lottery element here too - would some areas of a given country make much greater demands of resident's privately owned car batteries than others?
    • kwhitefoot 6y ago
      > This storage isn't "free" to the vehicle owner Just set the price at which you are willing to sell so that you make a profit overall.
• beaconstudios 6y ago
  one of the most interesting strategies for grid storage I've seen is just pumping water up a hill. Then, when you want to get the energy back, just let it flow back down through turbines. https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit... One of the potential strategies for dealing with grid storage in Europe is to turn Norway into a battery: https://www.greentechmedia.com/articles/read/experts-respond-to-norway-battery-pack-dismissal https://www.greentechmedia.com/articles/read/experts-respond... Very neat engineering.
  • sefrost 6y ago
    I read about a similar idea using abandoned mine shafts. https://www.theengineer.co.uk/abandoned-mine-shafts-energy-storage/ https://www.theengineer.co.uk/abandoned-mine-shafts-energy-s...
    • beaconstudios 6y ago
      oh I've heard about that one too actually - don't they suspend a large weight and use its potential energy as storage? I'm a sucker for these back-to-basics engineering projects. High tech batteries be damned, let's just use potential energy for storage!
      • _Microft 6y ago
        There is a German company suggesting to cut a large piece of rock (think: hundreds of meters in diameter and depth) lose and lift that by pumping water beneath it. A moving mountain, it would be. Totally crazy stuff, I should check if that ever made any progress. Here is a German article about it. As far as I remember, the real issue is that pumps/generators with the required powers are very expensive. https://www.ingenieur.de/technik/fachbereiche/energie/lageenergie-ein-riesen-felsklotz-idealer-stromspeicher/ https://www.ingenieur.de/technik/fachbereiche/energie/lageen...
        • billbrown 6y ago
• pydry 6y ago
  There hasn't been nearly enough done on demand shaping. Rather than wondering how we can store all the excess capacity it's probably more cost effective to wonder how we can shift demand. Aluminum smelters in Germany use gargantuan amounts of electricity, for instance, but they can use 3x as much on Friday when power is cheap than Monday when it's not with relative ease. Using a powerwall to keep production steady would be a ridiculous waste of money. Storage heaters need to make a comeback, as well.
  • VBprogrammer 6y ago
    The challenge with this kind of stuff is that capital costs are a big part of the cost for large industrial plants. A plant which is only using 25% of its capacity is going to be unprofitable.
    • bluGill 6y ago
      When the biggest input cost is energy you are wrong. A plant that is 10% capacity by running only when energy is cheap is more profitable than a plant at 90% running at whatever energy prices are. (in the real world take my numbers and reduce by 75% - between nights, weekends, and maintenance shutdowns a real industrial plant at 25% capacity is already common) The company I work for has two plants near each other, where one is run in winter, and one in summer, each producing a different product. The workers alternate between which plant they work at depending on the season. The other plant is shutdown for maintenance. By replacing the conveyor belt every year we ensure production never shuts down unexpectedly while people are working, and this more than makes up for the cost of a factory that is idle half of the year. We have a lot of factories. The above two plants are not the foundry where we pour iron which I talked about in a different thread.
      • VBprogrammer 6y ago
        Without knowing what industry you are talking about it's hard to engage in any meaningful dialog. It clearly doesn't matter what percentage of the input cost is energy to whether the plant is profitable. So long as that percentage is non-zero there will always be an energy cost at which the total cost to produce is higher than the market price to sell (ask any industry in Texas). Clearly there are other factors too, in your example it seems like labour costs are very high or perhaps contractual demands on output mean down time is unacceptable.
• Corazoor 6y ago
  > but the challenges of needing to store such vast amounts of energy seems like an almost impossible task Only if you don't look at all available solutions: https://en.wikipedia.org/wiki/Power-to-gas https://en.wikipedia.org/wiki/Power-to-gas "P2G is often considered the most promising technology for seasonal renewable energy storage" I dunno why this is such an unknown technique, natural gas storage is a very old and proven technology. Yet it is ommitted from almost any discussion about the subject...
  • sofixa 6y ago
    If you convert Power to Gas in the form of LPG or methane you then burn for energy when renewables aren't working, you're kinda defeating one of the main purposes of renewables - low carbon output.
    • bluGill 6y ago
      No, you are carbon neutral. The most obvious (though maybe not best) way to do this is turn separate water into H and O, then store the H in a tank. When you need more power you burn the H getting water back. This process is not very efficient, but when power is cheap who cares. You can also turn CO2 into synthetic oil (Methane, gasoline, Jet fuel, motor oil - your choice of what you want) via known processes. Again the process isn't very efficient, but when the inputs are free who cares. The sum of is carbon neutral.
    • Corazoor 6y ago
      That is simply not true. In order to convert elecricity to methane you first have to REMOVE CO2 from the enviroment. If you subsequently burn that gas, you arrive back at the CO2 level you had before the P2G process. That of course only works out to net zero when you use co2 that was recently captured, like from waste-biogas or trees. The big problem with fossil fuels is not directly that they release CO2, it is that they release CO2 that was captured over millenia in the comparatively short timespan of decades. You can avoid that problem entirely with P2G systems.
  • sir_bearington 6y ago
    Power to gas needs a source of carbon to produce methane. No, the carbon dioxide in the atmosphere is not a good candidate for this, since it's at very low concentration. Theoretically one could use biomass, but thats a very inefficient method of carbon collection. Also, exist prototype power to gas facilities are ~50% efficient, just for the power-to-gas step. Even with a 66% efficient combined cycle gas turbine, which is the best we have, net efficiency is ~33%.
• TYPE_FASTER 6y ago
  Yes, at least one utility in Vermont is offering discounted Tesla Powerwall leases: https://greenmountainpower.com/rebates-programs/home-energy-storage/powerwall/ https://greenmountainpower.com/rebates-programs/home-energy-.... No solar installation is required. The utility keeps the battery charged, uses the power during times of peak load for the grid, and the homeowner can use the battery as a backup power source.