11 ms·

For long term energy storage batteries are not ideal. Their costs increase linearly with time of storage and amount of storage. Peak shaving is an OK use for

For long term energy storage batteries are not ideal. Their costs increase linearly with time of storage and amount of storage. Peak shaving is an OK use for them, though.

est31 7y ago
Also batteries lose their stored energy over time.
ZeroGravitas 7y ago
What percentage of our global storage needs do you believe are "long term" in this dichotomy? Is this at the "electric cars can't do my daily commute" or "electric cars can't tow my boat 600 miles without stopping, once a year" stage? Seems like most of the world just needs solar to last until the next day with a decent chunk of that power needed immediately after the sun sets and any wind power available could get smoothed out and/or stored for the morning by the same batteries.
- StavrosK 7y ago
  If an electric car can do 200km on a charge, that's 99.9% of my annual driving needs met.
- the8472 7y ago
  The sun does not shine every day. And not equally throughout all seasons. As the percentage of renewables increases so will the gaps on bad days/weeks. The differences can be dramatic and must be compensated some way. https://www.energy-charts.de/power.htm?source=solar-wind&year=2019&month=1 https://www.energy-charts.de/power.htm?source=solar-wind&yea...
  - ZeroGravitas 7y ago
    I'm familiar with the concept of seasons, just as I'm familiar with the concept of yearly boat trips. But lots of people live near the equator, just like lots of people don't really ever go for long drives so rather than focus on one particularly difficult case and then giving up I was looking for some kind of rough quantification of the problem. In analogy I'm just wondering whether the equivalent of the "daily commute" for most of the planet can be easily covered with current tech at a cost less than curent alternatives and we only need to worry about a comparitively small fraction that remains, which we could apply those savings to dealing with.
    - the8472 7y ago
      Equatorial weather patterns are not all that relevant because most of the energy consumption is at higher latitudes which experience significant seasonality. And your daily commute/boat towing "analogy" is not really helpful because those problems are not comparable. Boat towing is an optional luxury and can be worked around at a slight inconvenience by visiting charging stations. Lack of long-term storage on the other hand can't be worked around, it requires double-spending to keep dispatchable fossil fuel plants in standby. And I don't think there is a dichotomy either. Variability exists on a continuous time-scale from seconds to seasons, so storage solutions can expand along that continuum.
      - pfdietz 7y ago
        95% of the world population lives below 50 degrees N/S. And I suspect if seasonality really does become a problem that's costly to solve, heavy industry will move down toward the equator. Ship the finished products rather than try to make them where it doesn't make sense to.
        the8472 7y ago
        I intentionally wrote energy consumption instead of population because those distributions differ.
  - SECProto 7y ago
    Short term solution: natural gas peaker plants could be repurposed to provide power during lulls in production (better than most fossil fuels, but very expensive and still produce greenhouse gases, so can't be the solution for long) Medium term solution: long-distance transmission, overprovision, and even more grid-scale storage (whole continents don't get cloudy & calm at once for long periods of time) Potential long term solution: space-based solar (power is 24/7, just need lots of landing locations + distribution, because microwaves are attenuated by atmospheric moisture) Edit: tl;dr is that for the issues, there are many potential solutions
    - WanderPanda 7y ago
      Wont introducing net energy to the earth add to the warming?
      - esotericn 7y ago
        Not substantially. The issue is that energy that would normally escape does not.
      - riffraff 7y ago
        I may be incorrect, but space based solar would catch energy that would reach the earth anyway, basically shading us. So it would probably be more or less adding the same energy, but sending it to the ground rather than dispersing some in the stratosphere.
        pfdietz 7y ago
        That's incorrect, sorry.
        riffraff 7y ago
        ok, but can you explain why, please?
        7y ago
- pfdietz 7y ago
  Short term = diurnal Long term = weeks to seasonal Batteries, especially that sort of cheaper battery, would be great for diurnal load leveling. Long term storage is probably more hydrogen and mass thermal storage. The tradeoff would be capital cost per unit stored energy vs. efficiency. Storage competes with and complements two other approaches: overinstallation of generation capacity w. curtailment, and dispatchable demand. Curtailment involves installing more wind and PV than you need, and curtailing its output when supply > demand. A study in Minnesota found that this was cheaper than adding storage up to about 70% of the electrical power supply. Of course this creates dirt-cheap power during the curtailed periods that people can find use for (industrial thermal storage, production of hydrogen in low capital cost membraneless electrolyzers). Dispatchable demand would involve redesign of industrial processes to operate in fits and starts. For example, today's aluminum cells do not respond well to inconstant power sources (their either freeze up or overheat and damage the lining). This was fine when the cheapest power sources were baseload sources. But perhaps an aluminum technology could be developed that would be more forgiving of variation and outages, to exploit the new situation where intermittent power is becoming the cheapest. Of course, another approach is to move those industrial processes down close to the equator, where there is little seasonal variation in insolation. High latitude countries may become industrially disadvantaged in a renewable powered world.
  - Retric 7y ago
    Multi day storage is always an issue. X kWh stored over Y hours takes X kWh of storage but X/Y kw of generation capacity. Start talking 50 hours and the cost difference becomes huge. PS: Though batteries inherently have some emergency storage capacity as daily deep discharge is inefficient.
  - magicalhippo 7y ago
    > Long term storage is probably more hydrogen and mass thermal storage. I was thinking about how multiple big heating packs[1] would stack up. Seems the Wikipedia reference[2] has the topic well covered. Tricky but possible. And apparently (duh) not a novel idea by any means[3][4]. Though the references I could find were mostly for home-size installations or for actual heating packs. Here in Norway we're blessed with lots of mountains with lakes, so we can do pumped hydro for latent storage. But for flatter countries (say our neighbors Denmark), is grid-size PCM storage viable? [1]: https://en.wikipedia.org/wiki/Sodium_acetate https://en.wikipedia.org/wiki/Sodium_acetate [2]: https://books.google.com/books?id=EsfcWE5lX40C&q=latent+heat+of+fusion+sodium+acetate#search https://books.google.com/books?id=EsfcWE5lX40C&q=latent+heat... [3]: https://www.sciencedirect.com/science/article/abs/pii/S1359431115008510 https://www.sciencedirect.com/science/article/abs/pii/S13594... [4]: https://ideas.repec.org/a/eee/appene/v221y2018icp522-534.html https://ideas.repec.org/a/eee/appene/v221y2018icp522-534.htm...
- michaelt 7y ago
  What percentage of our global storage needs do you believe are "long term" in this dichotomy? Solar output in the UK varies substantially between summer and winter [1] - as does demand for heating. As a Brit with solar panels, it would be super neat if I could generate power during the summer, store it for 6 months, and use it for heating during winter. That would reduce my direct carbon emissions relative to the status quo, which is burning natural gas for heating during winter. However, replacing my (fairly modest AFAIK) £222-per-year gas bill would need ~150 Tesla Power Wall packs, costing several times the value of the home being heated. [1] https://pvoutput.org/aggregate.jsp?p=0&id=4768&sid=3764&t=m&v=0&o=date&d=desc https://pvoutput.org/aggregate.jsp?p=0&id=4768&sid=3764&t=m&...
  - afarrell 7y ago
    For this, wouldn't it be better to pump water onto the top of a bunch of mountains in Wales? https://en.wikipedia.org/wiki/Dinorwig_Power_Station https://en.wikipedia.org/wiki/Dinorwig_Power_Station, but more.
    - riffraff 7y ago
      That's the point, isn't it? Batteries are not a panacea for energy storage needs, even with a doubling of their capacity.
      - strainer 7y ago
        There is no requirement for a panacea or super neat developments that allow individual households to store seasons worth of privately generated electricity. For seasonal and sporadic production shortfalls in solar and wind generation, biofuels and electrically synthesized fuels can fill in. On the occasions where carbon-neutral fuel resources are insufficient - gas generation can remain as fallback (increasingly rarely) until sufficient carbon neutral fuel production is developed.
        pfdietz 7y ago
        And with atmospheric CO2 capture, CO2 released by intermittent fallback fossil combustion can be scrubbed at a rate well below the peak release rate at the turbines.
- dwighttk 7y ago
  >Seems like most of the world just needs solar to last until the next day as long as it's not cloudy for a week
  - ZeroGravitas 7y ago
    Did the person sizing the solar panels in this hypothetical forget that it was sometimes cloudy? Seems a rather silly mistake. Wouldn't they have access to data predicting to within fairly narrow margins how often this would occur statistically? I mean if cloudy weather reduces the output by a factor of 4 then you don't really need to bring long term storage into the matter to have trouble if you're going size everything on the basis that will only provide the required energy on the very sunniest days.
    - dwighttk 7y ago
      You are going to build panels that will provide enough energy for one day on the day it is the least sunny at the site? What do you do with the excess on sunny days?
      - yourMadness 7y ago
        Whatever seems useful. Or do the inverse of the power satellite idea: send the excess energy to space as microwaves.
      - kragen 7y ago
        You can turn it off. Solar panels can be turned off in nanoseconds with nothing more than a transistor. Or you can invest the zero-cost energy in something potentially useful that doesn't need a constant power supply: electrowinning metals, removing corrosion, heating the hot tub back up, making ice to run your fridge or air conditioner when there's less sun, running low-cost machine tools (the kind where the depreciation is insignificant compared to the cost of power and consumables), generating hydrogen by electrolysis to convert into methane or methanol or ethanol for fuel, baking some bread, washing some laundry, doing a short pottery firing in your kiln (<8 hours), recharging your electric car, in short any of a wide variety of processes.
jhayward 7y ago
Is there any storage mechanism whose costs don't increase in the same way?
- the8472 7y ago
  Anything that involves volumes and abundant resources. E.g. storing hydrogen or compressed air in a salt dome decouples the power rating of your storage (MW) from the storage capacity (MWh). Similarly hydroelectric dams contain water by volume but you only need to dam a cross-section of the valley.
  - jhayward 7y ago
    Wouldn't the above description also fit flow batteries?
    - the8472 7y ago
      It's a little less clear-cut since you still need to pay a linear cost for the electrolyte, but it should be much lower than the same amount of Li-ion storage, at least in raw material costs.
  - SECProto 7y ago
    > Similarly hydroelectric dams contain water by volume but you only need to dam a cross-section of the valley. I would caution that the cost of a dam does not increase linearly, either (and that most resources that are profitably dammable at utility scale have already been dammed)
diafygi 7y ago
Luckily, there's plenty of carbon to offset (peakers) by deploying batteries before we have to worry about long term (seasonal) storage. However, I wouldn't be surprised if the electrification of transportation ends up making batteries be the default "long term" storage option by using EVs as flexible grid storage. There's going to be 100x more batteries rolling around than what you'd need to stabilize the grid (e.g. peakers), so I wouldn't be surprised if the grid asks more from EVs than just stability so it doesn't have to spend the additional capital for seasonal storage.
- gwbas1c 7y ago
  Somehow, I think people waking up to find out that their EV doesn't have the charge they expected it to have will put that idea in its place. The idea that someone with an EV will allow the power company to randomly deplete its battery is a fantasy. Edit: We're much more likely to see home standby generators put to that use, or home batteries (connected to solar) put to that use.
  - diafygi 7y ago
    Keep in mind that we're talking about single digit percentages of a battery's capacity being used. Also, its likely that many of the EV-to-grid arrangements will be for fleet vehicles (company/city cars, plus self-driving fleets when they happen), and they will be technically sophisticated enough to negotiate that capacity sharing with the grid operators. So you won't ever actually have a scenario you describe where a private EV will have it's battery depleted.
    - ahartman00 7y ago
      "likely that many of the EV-to-grid arrangements will be for fleet vehicles" Wont these be out and about during the day when the sun is shining and need to be charged during the night? Seems like these are the opposite of storage, they would exacerbate the problem? Creating a lot of demand(lots of buses in lots of cities) charging at night, and driving during the day. "will be technically sophisticated" This is an assumption, though it does seem technically possible. "scenario you describe where a private EV will have it's battery depleted" Im an environmentalist myself, but if I wake up on the morning of my vacation, and my car is at < 100%, I'm not going to be happy. You might say you could provide a way to signal that your car needs to be at 100%, but I see a non trivial amount of people enabling that all the time. I guess if we require every parking lot with > x spaces to have plugs for all vehicles to charge/store during the day. Still requires people to actually bother plugging them in. Of course, they would also have to plug them in during the night, and unless they are getting paid to, I dont see people going through the minor hassle if it is no benefit to them. I'm just not really optimistic about the vehicles as storage idea, sadly. Sorry for the pessimism, but I feel like there is too much naive hand waving among environmentalists. I think we need a more realistic, critical discussion, focused on likely, probable solutions. Theres too much: "Everybody can just go out of their way too do x." Theres still people who think putting an aluminum can in a different bin is too much work. We have to work with these unfortunate realities, not just dismiss them.
laurencerowe 7y ago
I'm not sure long term storage will ever make sense since the capital costs are amortized across far fewer cycles. Once a year rather than once a day means 365x the capital cost. Instead over-provisioning of green generation and increasing grid capacity (to avoid risk of local week long lulls in generation) seems a much better bet.
- pfdietz 7y ago
  So what is needed for that is a solution that trades lower efficiency for lower capital cost. Hydrogen burned in gas turbines may be that solution, if the cost of mediocre efficiency electrolyzers can be made low enough.

For long term energy storage batteries are not ideal. Their costs increase linearly with time of storage and amount of storage. Peak shaving is an OK use for them, though.

est31 7y ago

Also batteries lose their stored energy over time.

ZeroGravitas 7y ago

What percentage of our global storage needs do you believe are "long term" in this dichotomy? Is this at the "electric cars can't do my daily commute" or "electric cars can't tow my boat 600 miles without stopping, once a year" stage? Seems like most of the world just needs solar to last until the next day with a decent chunk of that power needed immediately after the sun sets and any wind power available could get smoothed out and/or stored for the morning by the same batteries.

StavrosK 7y ago
If an electric car can do 200km on a charge, that's 99.9% of my annual driving needs met.
the8472 7y ago
The sun does not shine every day. And not equally throughout all seasons. As the percentage of renewables increases so will the gaps on bad days/weeks. The differences can be dramatic and must be compensated some way. https://www.energy-charts.de/power.htm?source=solar-wind&year=2019&month=1 https://www.energy-charts.de/power.htm?source=solar-wind&yea...
- ZeroGravitas 7y ago
  I'm familiar with the concept of seasons, just as I'm familiar with the concept of yearly boat trips. But lots of people live near the equator, just like lots of people don't really ever go for long drives so rather than focus on one particularly difficult case and then giving up I was looking for some kind of rough quantification of the problem. In analogy I'm just wondering whether the equivalent of the "daily commute" for most of the planet can be easily covered with current tech at a cost less than curent alternatives and we only need to worry about a comparitively small fraction that remains, which we could apply those savings to dealing with.
  - the8472 7y ago
    Equatorial weather patterns are not all that relevant because most of the energy consumption is at higher latitudes which experience significant seasonality. And your daily commute/boat towing "analogy" is not really helpful because those problems are not comparable. Boat towing is an optional luxury and can be worked around at a slight inconvenience by visiting charging stations. Lack of long-term storage on the other hand can't be worked around, it requires double-spending to keep dispatchable fossil fuel plants in standby. And I don't think there is a dichotomy either. Variability exists on a continuous time-scale from seconds to seasons, so storage solutions can expand along that continuum.
    - pfdietz 7y ago
      95% of the world population lives below 50 degrees N/S. And I suspect if seasonality really does become a problem that's costly to solve, heavy industry will move down toward the equator. Ship the finished products rather than try to make them where it doesn't make sense to.
      - the8472 7y ago
        I intentionally wrote energy consumption instead of population because those distributions differ.
- SECProto 7y ago
  Short term solution: natural gas peaker plants could be repurposed to provide power during lulls in production (better than most fossil fuels, but very expensive and still produce greenhouse gases, so can't be the solution for long) Medium term solution: long-distance transmission, overprovision, and even more grid-scale storage (whole continents don't get cloudy & calm at once for long periods of time) Potential long term solution: space-based solar (power is 24/7, just need lots of landing locations + distribution, because microwaves are attenuated by atmospheric moisture) Edit: tl;dr is that for the issues, there are many potential solutions
  - WanderPanda 7y ago
    Wont introducing net energy to the earth add to the warming?
    - esotericn 7y ago
      Not substantially. The issue is that energy that would normally escape does not.
    - riffraff 7y ago
      I may be incorrect, but space based solar would catch energy that would reach the earth anyway, basically shading us. So it would probably be more or less adding the same energy, but sending it to the ground rather than dispersing some in the stratosphere.
      - pfdietz 7y ago
        That's incorrect, sorry.
        riffraff 7y ago
        ok, but can you explain why, please?
        7y ago
pfdietz 7y ago
Short term = diurnal Long term = weeks to seasonal Batteries, especially that sort of cheaper battery, would be great for diurnal load leveling. Long term storage is probably more hydrogen and mass thermal storage. The tradeoff would be capital cost per unit stored energy vs. efficiency. Storage competes with and complements two other approaches: overinstallation of generation capacity w. curtailment, and dispatchable demand. Curtailment involves installing more wind and PV than you need, and curtailing its output when supply > demand. A study in Minnesota found that this was cheaper than adding storage up to about 70% of the electrical power supply. Of course this creates dirt-cheap power during the curtailed periods that people can find use for (industrial thermal storage, production of hydrogen in low capital cost membraneless electrolyzers). Dispatchable demand would involve redesign of industrial processes to operate in fits and starts. For example, today's aluminum cells do not respond well to inconstant power sources (their either freeze up or overheat and damage the lining). This was fine when the cheapest power sources were baseload sources. But perhaps an aluminum technology could be developed that would be more forgiving of variation and outages, to exploit the new situation where intermittent power is becoming the cheapest. Of course, another approach is to move those industrial processes down close to the equator, where there is little seasonal variation in insolation. High latitude countries may become industrially disadvantaged in a renewable powered world.
- Retric 7y ago
  Multi day storage is always an issue. X kWh stored over Y hours takes X kWh of storage but X/Y kw of generation capacity. Start talking 50 hours and the cost difference becomes huge. PS: Though batteries inherently have some emergency storage capacity as daily deep discharge is inefficient.
- magicalhippo 7y ago
  > Long term storage is probably more hydrogen and mass thermal storage. I was thinking about how multiple big heating packs[1] would stack up. Seems the Wikipedia reference[2] has the topic well covered. Tricky but possible. And apparently (duh) not a novel idea by any means[3][4]. Though the references I could find were mostly for home-size installations or for actual heating packs. Here in Norway we're blessed with lots of mountains with lakes, so we can do pumped hydro for latent storage. But for flatter countries (say our neighbors Denmark), is grid-size PCM storage viable? [1]: https://en.wikipedia.org/wiki/Sodium_acetate https://en.wikipedia.org/wiki/Sodium_acetate [2]: https://books.google.com/books?id=EsfcWE5lX40C&q=latent+heat+of+fusion+sodium+acetate#search https://books.google.com/books?id=EsfcWE5lX40C&q=latent+heat... [3]: https://www.sciencedirect.com/science/article/abs/pii/S1359431115008510 https://www.sciencedirect.com/science/article/abs/pii/S13594... [4]: https://ideas.repec.org/a/eee/appene/v221y2018icp522-534.html https://ideas.repec.org/a/eee/appene/v221y2018icp522-534.htm...
michaelt 7y ago
What percentage of our global storage needs do you believe are "long term" in this dichotomy? Solar output in the UK varies substantially between summer and winter [1] - as does demand for heating. As a Brit with solar panels, it would be super neat if I could generate power during the summer, store it for 6 months, and use it for heating during winter. That would reduce my direct carbon emissions relative to the status quo, which is burning natural gas for heating during winter. However, replacing my (fairly modest AFAIK) £222-per-year gas bill would need ~150 Tesla Power Wall packs, costing several times the value of the home being heated. [1] https://pvoutput.org/aggregate.jsp?p=0&id=4768&sid=3764&t=m&v=0&o=date&d=desc https://pvoutput.org/aggregate.jsp?p=0&id=4768&sid=3764&t=m&...
- afarrell 7y ago
  For this, wouldn't it be better to pump water onto the top of a bunch of mountains in Wales? https://en.wikipedia.org/wiki/Dinorwig_Power_Station https://en.wikipedia.org/wiki/Dinorwig_Power_Station, but more.
  - riffraff 7y ago
    That's the point, isn't it? Batteries are not a panacea for energy storage needs, even with a doubling of their capacity.
    - strainer 7y ago
      There is no requirement for a panacea or super neat developments that allow individual households to store seasons worth of privately generated electricity. For seasonal and sporadic production shortfalls in solar and wind generation, biofuels and electrically synthesized fuels can fill in. On the occasions where carbon-neutral fuel resources are insufficient - gas generation can remain as fallback (increasingly rarely) until sufficient carbon neutral fuel production is developed.
      - pfdietz 7y ago
        And with atmospheric CO2 capture, CO2 released by intermittent fallback fossil combustion can be scrubbed at a rate well below the peak release rate at the turbines.
dwighttk 7y ago
>Seems like most of the world just needs solar to last until the next day as long as it's not cloudy for a week
- ZeroGravitas 7y ago
  Did the person sizing the solar panels in this hypothetical forget that it was sometimes cloudy? Seems a rather silly mistake. Wouldn't they have access to data predicting to within fairly narrow margins how often this would occur statistically? I mean if cloudy weather reduces the output by a factor of 4 then you don't really need to bring long term storage into the matter to have trouble if you're going size everything on the basis that will only provide the required energy on the very sunniest days.
  - dwighttk 7y ago
    You are going to build panels that will provide enough energy for one day on the day it is the least sunny at the site? What do you do with the excess on sunny days?
    - yourMadness 7y ago
      Whatever seems useful. Or do the inverse of the power satellite idea: send the excess energy to space as microwaves.
    - kragen 7y ago
      You can turn it off. Solar panels can be turned off in nanoseconds with nothing more than a transistor. Or you can invest the zero-cost energy in something potentially useful that doesn't need a constant power supply: electrowinning metals, removing corrosion, heating the hot tub back up, making ice to run your fridge or air conditioner when there's less sun, running low-cost machine tools (the kind where the depreciation is insignificant compared to the cost of power and consumables), generating hydrogen by electrolysis to convert into methane or methanol or ethanol for fuel, baking some bread, washing some laundry, doing a short pottery firing in your kiln (<8 hours), recharging your electric car, in short any of a wide variety of processes.

jhayward 7y ago

Is there any storage mechanism whose costs don't increase in the same way?

the8472 7y ago
Anything that involves volumes and abundant resources. E.g. storing hydrogen or compressed air in a salt dome decouples the power rating of your storage (MW) from the storage capacity (MWh). Similarly hydroelectric dams contain water by volume but you only need to dam a cross-section of the valley.
- jhayward 7y ago
  Wouldn't the above description also fit flow batteries?
  - the8472 7y ago
    It's a little less clear-cut since you still need to pay a linear cost for the electrolyte, but it should be much lower than the same amount of Li-ion storage, at least in raw material costs.
- SECProto 7y ago
  > Similarly hydroelectric dams contain water by volume but you only need to dam a cross-section of the valley. I would caution that the cost of a dam does not increase linearly, either (and that most resources that are profitably dammable at utility scale have already been dammed)

diafygi 7y ago

Luckily, there's plenty of carbon to offset (peakers) by deploying batteries before we have to worry about long term (seasonal) storage. However, I wouldn't be surprised if the electrification of transportation ends up making batteries be the default "long term" storage option by using EVs as flexible grid storage. There's going to be 100x more batteries rolling around than what you'd need to stabilize the grid (e.g. peakers), so I wouldn't be surprised if the grid asks more from EVs than just stability so it doesn't have to spend the additional capital for seasonal storage.

gwbas1c 7y ago
Somehow, I think people waking up to find out that their EV doesn't have the charge they expected it to have will put that idea in its place. The idea that someone with an EV will allow the power company to randomly deplete its battery is a fantasy. Edit: We're much more likely to see home standby generators put to that use, or home batteries (connected to solar) put to that use.
- diafygi 7y ago
  Keep in mind that we're talking about single digit percentages of a battery's capacity being used. Also, its likely that many of the EV-to-grid arrangements will be for fleet vehicles (company/city cars, plus self-driving fleets when they happen), and they will be technically sophisticated enough to negotiate that capacity sharing with the grid operators. So you won't ever actually have a scenario you describe where a private EV will have it's battery depleted.
  - ahartman00 7y ago
    "likely that many of the EV-to-grid arrangements will be for fleet vehicles" Wont these be out and about during the day when the sun is shining and need to be charged during the night? Seems like these are the opposite of storage, they would exacerbate the problem? Creating a lot of demand(lots of buses in lots of cities) charging at night, and driving during the day. "will be technically sophisticated" This is an assumption, though it does seem technically possible. "scenario you describe where a private EV will have it's battery depleted" Im an environmentalist myself, but if I wake up on the morning of my vacation, and my car is at < 100%, I'm not going to be happy. You might say you could provide a way to signal that your car needs to be at 100%, but I see a non trivial amount of people enabling that all the time. I guess if we require every parking lot with > x spaces to have plugs for all vehicles to charge/store during the day. Still requires people to actually bother plugging them in. Of course, they would also have to plug them in during the night, and unless they are getting paid to, I dont see people going through the minor hassle if it is no benefit to them. I'm just not really optimistic about the vehicles as storage idea, sadly. Sorry for the pessimism, but I feel like there is too much naive hand waving among environmentalists. I think we need a more realistic, critical discussion, focused on likely, probable solutions. Theres too much: "Everybody can just go out of their way too do x." Theres still people who think putting an aluminum can in a different bin is too much work. We have to work with these unfortunate realities, not just dismiss them.

laurencerowe 7y ago

I'm not sure long term storage will ever make sense since the capital costs are amortized across far fewer cycles. Once a year rather than once a day means 365x the capital cost. Instead over-provisioning of green generation and increasing grid capacity (to avoid risk of local week long lulls in generation) seems a much better bet.

pfdietz 7y ago
So what is needed for that is a solution that trades lower efficiency for lower capital cost. Hydrogen burned in gas turbines may be that solution, if the cost of mediocre efficiency electrolyzers can be made low enough.