6 ms·

It's a great point. Even in my spot in northern California this winter, it's been so cloudy this year, I can't imaging an all solar+storage grid would have work

It's a great point. Even in my spot in northern California this winter, it's been so cloudy this year, I can't imaging an all solar+storage grid would have worked out well this year. In this case having electricity that costs 45% more when it's cloudy is a lot better than none at all. Actually this gave me an idea, it would be really neat to have an comprehensive simulator of power grids that incorporated weather, demand spikes etc. to play around with different energy source mix to get an idea of what actually works and when it fails as well as total cost, environmental impact etc.

mikeyouse 4y ago
> Even in my spot in northern California this winter, it's been so cloudy this year, I can't imaging an all solar+storage grid would have worked out well this year. The electricity demand in the winter is much lower than the summer demand, especially in California due to residential AC. > Actually this gave me an idea, it would be really neat to have an comprehensive simulator of power grids that incorporated weather, demand spikes etc. to play around with different energy source mix to get an idea of what actually works and when it fails as well as total cost, environmental impact etc. There's a gentleman in Australia who does ~this for their market -- 5 hours of storage is enough to get to a 99% renewable grid there; https://twitter.com/DavidOsmond8/status/1640959088887730176 https://twitter.com/DavidOsmond8/status/1640959088887730176
- seiferteric 4y ago
  With heat pumps coming online and gas being phased out that might not be true for very long. Also is 99% even close to good enough? That would be like 4 days a year without power right?
  - Godel_unicode 4y ago
    And induction cooktops, and home charging BEVs overnight…
    - seiferteric 4y ago
      my back of the envelope calculation based on current human energy usage and battery production, it would take more than 150 years to manufacture 5 hours storage capacity. Of course manufacturing capacity is increasing and efficiency improves with electrification, but so is energy consumption, plus you have to factor in battery replacements during that time... Ya its going be tough to do that.
      - syntheweave 4y ago
        It's a more complex calculation than that because not all the energy storage is going to use battery electric. Pumped storage hydro is often pointed to as one option for mass quantities over a long durations, and somewhat more esoteric stuff like low-friction flywheels comes up for "capacitor" type loads where what's needed is a cycle of a few minutes. The advantage of the batteries is specifically in power density, which makes them suited for mobility and consumer convenience. But the more you get into seriously optimizing electrical storage for scale, the less it's going to be about one specific mode.
      - mikeyouse 4y ago
        No offense to your envelope, but that feels like a silly assumption. We produced ~15GWH of batteries in 2010 and now that takes us something like 3 weeks? Planned capacity additions will make that a daily production amount by 2030, and each subsequent cell is cheaper than the one before. This also assumes Li Ion as the only game in town. Plenty of other more likely options (flow batteries, hydro, etc) are feasible on a 15-year horizon. 5 Hours of electricity is something like 13 TWh, so if we get to 5,500 GWh annual production by 2030, it would take ~2.5 years to provide 5 hours of global electricity storage. Handicap it all and double the electricity requirement and halve the annual production figures and it's still only 10 years' capacity to go to a 99% carbon-free grid.
        seiferteric 4y ago
        No 13 TWh is just our current _electricity_ consumption for 5 hours. We are talking about replacing all energy consumption like heating with electric heat pumps etc. This would be closer to 100TWh. And google says our current production is around 600GWh of batteries per year. 91.89 TWh / 600 GWh/year = 153 years. Yes there is pumped storage, but I wonder how much more of that there really is to develop? Plus damns are environmental disasters of their own. The other storage methods are speculative at best. I just wanted to push back a bit on the idea that "just" need solar + storage as many people seem to believe. It is a big ask, and I think we will need more. If we don't want gas plants, then nuclear could be a good option.
  - mikeyouse 4y ago
    The premise isn't that you'd just sit in the dark when there isn't enough renewable + storage -- you'd run nat gas peaker plants or some carbon-based source for those 1% of times when it's needed -- would still almost entirely decarbonize the grid.
    - liketochill 4y ago
      How do you make it worthwhile for someone to have a natural gas peaker plant ready to run at any time for only 1% of hours in a year? Where does that cost figure in the tradeoff between renewables + batteries vs nuclear?
      - mikeyouse 4y ago
        We have really good insight into week-ahead curves for wind and solar, and high quality prediction for day-ahead production, so it wouldn't need to be ready "at any time" like its usage would be a surprise. And you incentivize it like anything else, providing either a $/kwh figure that makes it economical for them to capture their costs or subsidize the construction and standby nature of them like we currently do with black start generators (https://www.kut.org/energy-environment/2021-08-05/if-the-texas-power-grid-had-gone-down-it-would-need-a-black-start-how-long-would-that-take https://www.kut.org/energy-environment/2021-08-05/if-the-tex...). It's hard to make a reliable cost prediction comparing nuclear vs. wind/solar + batteries since we don't know how to build nuclear any more. Vogtle 3/4 are going to cost maybe $40 billion when all's said and done? With OpEx, you get to something like $0.18/kwh. That's more than 5x the cost of unsubsidized wind or solar installations which would buy you a bunch of storage.
        liketochill 4y ago
        I agree the reserve mechanisms provide the incentive to pay generators to exist with an entire gas turbine, generator, switchgear, operations staff, health and safety staff, maintenance staff, transformer, interconnection, land, environmental permits, hr and accounting departments to be “available” but not generate except in the time that renewables can’t. The only difference in cost for the plant to exist and not run but be ready and to run is the cost of the fuel. So we still have to pay for dispatchable generation if we want to have power on a calm cloudy day week. We can add that cost to the cost of the storage and overbuilding of capacity that allows solar or wind to deliver rated power overnight. Or live with blackouts
- TaylorAlexander 4y ago
  > The electricity demand in the winter is much lower than the summer demand, especially in California due to residential AC. My mom's house doesn't need A/C but it does need a lot of heat in the winter. We looked at moving her to solar/battery and an electric heat pump instead of her gas furnace. With even a tiny bit of trees nearby and otherwise pretty good exposure we were told it was going to be hard to make it worth it. Her demand in the winter would be pretty high.
  - PaulDavisThe1st 4y ago
    We generate 3x our needs in summer; 1/3 of our needs in winter, when we are running electric air source heat pumps at 6000' in northern NM. If we had a passivhaus-level home, I think it could be possible to satisfy the winter heat requirements with the solar we have, but not with anything less (and even then, it would be challenging).
    - TaylorAlexander 4y ago
      Interesting, I appreciate the information. What is the nominal capacity of your solar array?
      - PaulDavisThe1st 4y ago
        6.7kW We typically generate 800kW - 1300kW per month (more in the summer). Our panels are angled at 30 degrees to slightly preference winter generation.
        TaylorAlexander 4y ago
        Great, thanks!

mikeyouse 4y ago

> Even in my spot in northern California this winter, it's been so cloudy this year, I can't imaging an all solar+storage grid would have worked out well this year. The electricity demand in the winter is much lower than the summer demand, especially in California due to residential AC. > Actually this gave me an idea, it would be really neat to have an comprehensive simulator of power grids that incorporated weather, demand spikes etc. to play around with different energy source mix to get an idea of what actually works and when it fails as well as total cost, environmental impact etc. There's a gentleman in Australia who does ~this for their market -- 5 hours of storage is enough to get to a 99% renewable grid there; https://twitter.com/DavidOsmond8/status/1640959088887730176 https://twitter.com/DavidOsmond8/status/1640959088887730176

seiferteric 4y ago
With heat pumps coming online and gas being phased out that might not be true for very long. Also is 99% even close to good enough? That would be like 4 days a year without power right?
- Godel_unicode 4y ago
  And induction cooktops, and home charging BEVs overnight…
  - seiferteric 4y ago
    my back of the envelope calculation based on current human energy usage and battery production, it would take more than 150 years to manufacture 5 hours storage capacity. Of course manufacturing capacity is increasing and efficiency improves with electrification, but so is energy consumption, plus you have to factor in battery replacements during that time... Ya its going be tough to do that.
    - syntheweave 4y ago
      It's a more complex calculation than that because not all the energy storage is going to use battery electric. Pumped storage hydro is often pointed to as one option for mass quantities over a long durations, and somewhat more esoteric stuff like low-friction flywheels comes up for "capacitor" type loads where what's needed is a cycle of a few minutes. The advantage of the batteries is specifically in power density, which makes them suited for mobility and consumer convenience. But the more you get into seriously optimizing electrical storage for scale, the less it's going to be about one specific mode.
    - mikeyouse 4y ago
      No offense to your envelope, but that feels like a silly assumption. We produced ~15GWH of batteries in 2010 and now that takes us something like 3 weeks? Planned capacity additions will make that a daily production amount by 2030, and each subsequent cell is cheaper than the one before. This also assumes Li Ion as the only game in town. Plenty of other more likely options (flow batteries, hydro, etc) are feasible on a 15-year horizon. 5 Hours of electricity is something like 13 TWh, so if we get to 5,500 GWh annual production by 2030, it would take ~2.5 years to provide 5 hours of global electricity storage. Handicap it all and double the electricity requirement and halve the annual production figures and it's still only 10 years' capacity to go to a 99% carbon-free grid.
      - seiferteric 4y ago
        No 13 TWh is just our current _electricity_ consumption for 5 hours. We are talking about replacing all energy consumption like heating with electric heat pumps etc. This would be closer to 100TWh. And google says our current production is around 600GWh of batteries per year. 91.89 TWh / 600 GWh/year = 153 years. Yes there is pumped storage, but I wonder how much more of that there really is to develop? Plus damns are environmental disasters of their own. The other storage methods are speculative at best. I just wanted to push back a bit on the idea that "just" need solar + storage as many people seem to believe. It is a big ask, and I think we will need more. If we don't want gas plants, then nuclear could be a good option.
- mikeyouse 4y ago
  The premise isn't that you'd just sit in the dark when there isn't enough renewable + storage -- you'd run nat gas peaker plants or some carbon-based source for those 1% of times when it's needed -- would still almost entirely decarbonize the grid.
  - liketochill 4y ago
    How do you make it worthwhile for someone to have a natural gas peaker plant ready to run at any time for only 1% of hours in a year? Where does that cost figure in the tradeoff between renewables + batteries vs nuclear?
    - mikeyouse 4y ago
      We have really good insight into week-ahead curves for wind and solar, and high quality prediction for day-ahead production, so it wouldn't need to be ready "at any time" like its usage would be a surprise. And you incentivize it like anything else, providing either a $/kwh figure that makes it economical for them to capture their costs or subsidize the construction and standby nature of them like we currently do with black start generators (https://www.kut.org/energy-environment/2021-08-05/if-the-texas-power-grid-had-gone-down-it-would-need-a-black-start-how-long-would-that-take https://www.kut.org/energy-environment/2021-08-05/if-the-tex...). It's hard to make a reliable cost prediction comparing nuclear vs. wind/solar + batteries since we don't know how to build nuclear any more. Vogtle 3/4 are going to cost maybe $40 billion when all's said and done? With OpEx, you get to something like $0.18/kwh. That's more than 5x the cost of unsubsidized wind or solar installations which would buy you a bunch of storage.
      - liketochill 4y ago
        I agree the reserve mechanisms provide the incentive to pay generators to exist with an entire gas turbine, generator, switchgear, operations staff, health and safety staff, maintenance staff, transformer, interconnection, land, environmental permits, hr and accounting departments to be “available” but not generate except in the time that renewables can’t. The only difference in cost for the plant to exist and not run but be ready and to run is the cost of the fuel. So we still have to pay for dispatchable generation if we want to have power on a calm cloudy day week. We can add that cost to the cost of the storage and overbuilding of capacity that allows solar or wind to deliver rated power overnight. Or live with blackouts
TaylorAlexander 4y ago
> The electricity demand in the winter is much lower than the summer demand, especially in California due to residential AC. My mom's house doesn't need A/C but it does need a lot of heat in the winter. We looked at moving her to solar/battery and an electric heat pump instead of her gas furnace. With even a tiny bit of trees nearby and otherwise pretty good exposure we were told it was going to be hard to make it worth it. Her demand in the winter would be pretty high.
- PaulDavisThe1st 4y ago
  We generate 3x our needs in summer; 1/3 of our needs in winter, when we are running electric air source heat pumps at 6000' in northern NM. If we had a passivhaus-level home, I think it could be possible to satisfy the winter heat requirements with the solar we have, but not with anything less (and even then, it would be challenging).
  - TaylorAlexander 4y ago
    Interesting, I appreciate the information. What is the nominal capacity of your solar array?
    - PaulDavisThe1st 4y ago
      6.7kW We typically generate 800kW - 1300kW per month (more in the summer). Our panels are angled at 30 degrees to slightly preference winter generation.
      - TaylorAlexander 4y ago
        Great, thanks!