5 ms·

I haven't ignored the part where you mentioned overprovisioning. Where do you propose to put the excess power during sunny days? Stable baseline sources like nu

I haven't ignored the part where you mentioned overprovisioning. Where do you propose to put the excess power during sunny days? Stable baseline sources like nuclear cannot just be shut down or spun up on a moment's notice to accomodate a vast number of solar energy entering or leaving the grid. At the same time, we don't have a capability to store electricity at sufficient scale so we do need the stable baseline to cover a high enough percentage of our production. The fact of the matter is, as long as we don't have a scalable storage solution, power sources where we can't regulate the power output cannot take up base load and can at best be a small overlay that can pick up load if the beneficial weather happens to coincide with higher load requirements.

Robotbeat 10y ago
This really is not a big technical problem. You simply don't output the power. This is trivial with any kind of decent power-optimizing inverter setup commonly available today. Solar PV isn't spinning a turbine that needs to find a load. If you disconnect a solar panel, it doesn't damage itself, it just sits there. But I'm sure we'd eventually find uses for this extra energy. Like producing ammonia for agriculture.
- opo 10y ago
  No one I know is opposed to renewable energy, but advocates really do everybody a disservice when they try to argue that an intermittent power source without storage is a reasonable replacement for base load power. As Bill Gates said in an interview "…They have this statement that the cost of solar photovoltaic is the same as hydrocarbon’s. And that’s one of those misleadingly meaningless statements. What they mean is that at noon in Arizona, the cost of that kilowatt-hour is the same as a hydrocarbon kilowatt-hour. But it doesn’t come at night, it doesn’t come after the sun hasn’t shone, so the fact that in that one moment you reach parity, so what? The reading public, when they see things like that, they underestimate how hard this thing is. So false solutions like divestment or “Oh, it’s easy to do” hurt our ability to fix the problems. Distinguishing a real solution from a false solution is actually very complicated." https://www.theatlantic.com/magazine/archive/2015/11/we-need-an-energy-miracle/407881/ https://www.theatlantic.com/magazine/archive/2015/11/we-need... (Gates is investing in 4th gen nuclear and energy storage companies so he is putting his money where his mouth is.)
  - Retric 10y ago
    The term Baseload power is not a goal, it's a Problem with some types of power not being flexible. In that context, soar is closer to Baseload power than peaking power plants. Yes, it currently better matches demand than Baseload power, but as you ramp it up the supply / demand miss mach will simply shift around the day. Turning on some peaking power plants at night vs the day is not a significant issue. Further, the solution is excess capacity not long term storage.
    - opo 10y ago
      You are handwaving away huge issues here. As Bill Gates said in the same interview I quoted from before: >"...It’s kind of ironic: Germany, by installing so much rooftop solar, has it that both their coal plants and their rooftop solar are available in the summer, and the price of power during the day actually goes negative—they pay people to take it. Then at night the only source is the coal, and because the energy companies have to recover their capital costs, they either raise the price because they’re not getting any return for the day, or they slowly go bankrupt. There are many people working on storage—batteries are a form of storage, and there’s a few others, like compressed air, hot metals. But it’s not at all clear that we will get grid-scale economic storage. We’re more than a factor of 10 away from the economics to get that."
      - Retric 10y ago
        Coal and nuclear are huge steam engines. They cool down when you turn them off which causes thermal stress and you then need to heat them up again before they can generate power. Thus Germany's problem is they have coal power plants in the first place. Gas turbines also have thermal stress, but they are designed for this and they loose vastly less power when you turn them off. With enough of them you can have zero storage and zero problems. Because storage is simply one solution to production / demand mismatch not the only one. Now yes, peaking power costs more but energy costing more at night is rational behavior and without subsidies you will minimize overall costs.
        10y ago
- WalterBright 10y ago
  You can use the excess to create fuel, such as cracking H out of H2O, and then use that to reduce the nighttime problem. I don't think it'll be hard to find a use for excess power.
  - deleted 10y ago
    [deleted]
- logfromblammo 10y ago
  Desalination of seawater seems a safe bet for excess solar power.
  - kpil 10y ago
    Ah! I was going to write water pump reservoirs or at some price point electrolysis + fuel cells, but making cheap water in the daytime is also good.
    - rtx 10y ago
      We already have a solution to all our energy needs. Funny to see people come up with outlandish suggestions. I am not sure what I am missing. Because logic points to only one direction.
      - badosu 10y ago
        Well... Outlandish is to think that replacing a huge amount of infrastructure of a type to another is as simple as your sentence makes it look like.
      - kpil 10y ago
        I don't think there is a viable solution for buffering solar or wind (or nuclear) with renewable sources, unless you happen to have access to a lot of hydro power. Dynamic remote cut-off of heaters, chargers, and other non-critical consumers is one suggestion, but the equipment cost is probably at least 100 Eur per consumer.
    - TheSpiceIsLife 10y ago
      By no measure is reverse osmosis or flash distillation of water cheap even if the energy is free. Imagine building a huge water desalination plant and only running it when there is excess power available on the grid. I can't see anyone wanting to invest in that, except maybe a financially myopic government, and they tend not to last very long.
      - 10y ago
extrapickles 10y ago
You can do things with the excess power that otherwise would be un-economical to do during a cloudy day. Things like smelting aluminum, desalinating water, etc take massive amounts of power.
- TheSpiceIsLife 10y ago
  You can't just do those things when the weather is good. Not without huge tax breaks to incentivise load following, because intermittent production of large scale industrial processes is hard and not cheap.
  - extrapickles 10y ago
    They already do this without any gov intervention. The local steel recycling plant only operates when power is cheap. While they do need some advance notice to make sure they have enough people to run, they probably can get a good enough idea from a weather forecast (power here is mostly hydro with a dollop of wind and fossil). Some processes are better fits than others. If you have 2-5x extra capacity that is sold cheap on sunny days, someone will figure out how to use it.
    - TheSpiceIsLife 10y ago
      Do we have any numbers on what it means that they run only when the power is cheap? Does that mean they can operate in 4hr windows? Or do they run have to run the furnace for a minimum period? A large quantity of steel takes a large amount of energy to melt.
      - maxerickson 10y ago
        Interesting question. Brief research says the cycle time is ~1 hour (or less): http://www.steel.org/making-steel/how-its-made/processes/processes-info/electric-arc-furnace-steelmaking.aspx http://www.steel.org/making-steel/how-its-made/processes/pro... It could also be a plant for shredding scrap, where I guess it wouldn't be a time issue so much (and if it doesn't have the material inflows to run full time, timing cheap power would make sense).
petre 10y ago
> Where do you propose to put the excess power during sunny days Heat up some molten salts or any phase change material, then run the steam through a generator. Or pump water uphill. Not very efficient but doable.

Robotbeat 10y ago

This really is not a big technical problem. You simply don't output the power. This is trivial with any kind of decent power-optimizing inverter setup commonly available today. Solar PV isn't spinning a turbine that needs to find a load. If you disconnect a solar panel, it doesn't damage itself, it just sits there. But I'm sure we'd eventually find uses for this extra energy. Like producing ammonia for agriculture.

opo 10y ago
No one I know is opposed to renewable energy, but advocates really do everybody a disservice when they try to argue that an intermittent power source without storage is a reasonable replacement for base load power. As Bill Gates said in an interview "…They have this statement that the cost of solar photovoltaic is the same as hydrocarbon’s. And that’s one of those misleadingly meaningless statements. What they mean is that at noon in Arizona, the cost of that kilowatt-hour is the same as a hydrocarbon kilowatt-hour. But it doesn’t come at night, it doesn’t come after the sun hasn’t shone, so the fact that in that one moment you reach parity, so what? The reading public, when they see things like that, they underestimate how hard this thing is. So false solutions like divestment or “Oh, it’s easy to do” hurt our ability to fix the problems. Distinguishing a real solution from a false solution is actually very complicated." https://www.theatlantic.com/magazine/archive/2015/11/we-need-an-energy-miracle/407881/ https://www.theatlantic.com/magazine/archive/2015/11/we-need... (Gates is investing in 4th gen nuclear and energy storage companies so he is putting his money where his mouth is.)
- Retric 10y ago
  The term Baseload power is not a goal, it's a Problem with some types of power not being flexible. In that context, soar is closer to Baseload power than peaking power plants. Yes, it currently better matches demand than Baseload power, but as you ramp it up the supply / demand miss mach will simply shift around the day. Turning on some peaking power plants at night vs the day is not a significant issue. Further, the solution is excess capacity not long term storage.
  - opo 10y ago
    You are handwaving away huge issues here. As Bill Gates said in the same interview I quoted from before: >"...It’s kind of ironic: Germany, by installing so much rooftop solar, has it that both their coal plants and their rooftop solar are available in the summer, and the price of power during the day actually goes negative—they pay people to take it. Then at night the only source is the coal, and because the energy companies have to recover their capital costs, they either raise the price because they’re not getting any return for the day, or they slowly go bankrupt. There are many people working on storage—batteries are a form of storage, and there’s a few others, like compressed air, hot metals. But it’s not at all clear that we will get grid-scale economic storage. We’re more than a factor of 10 away from the economics to get that."
    - Retric 10y ago
      Coal and nuclear are huge steam engines. They cool down when you turn them off which causes thermal stress and you then need to heat them up again before they can generate power. Thus Germany's problem is they have coal power plants in the first place. Gas turbines also have thermal stress, but they are designed for this and they loose vastly less power when you turn them off. With enough of them you can have zero storage and zero problems. Because storage is simply one solution to production / demand mismatch not the only one. Now yes, peaking power costs more but energy costing more at night is rational behavior and without subsidies you will minimize overall costs.
      - 10y ago
WalterBright 10y ago
You can use the excess to create fuel, such as cracking H out of H2O, and then use that to reduce the nighttime problem. I don't think it'll be hard to find a use for excess power.
- deleted 10y ago
  [deleted]
logfromblammo 10y ago
Desalination of seawater seems a safe bet for excess solar power.
- kpil 10y ago
  Ah! I was going to write water pump reservoirs or at some price point electrolysis + fuel cells, but making cheap water in the daytime is also good.
  - rtx 10y ago
    We already have a solution to all our energy needs. Funny to see people come up with outlandish suggestions. I am not sure what I am missing. Because logic points to only one direction.
    - badosu 10y ago
      Well... Outlandish is to think that replacing a huge amount of infrastructure of a type to another is as simple as your sentence makes it look like.
    - kpil 10y ago
      I don't think there is a viable solution for buffering solar or wind (or nuclear) with renewable sources, unless you happen to have access to a lot of hydro power. Dynamic remote cut-off of heaters, chargers, and other non-critical consumers is one suggestion, but the equipment cost is probably at least 100 Eur per consumer.
  - TheSpiceIsLife 10y ago
    By no measure is reverse osmosis or flash distillation of water cheap even if the energy is free. Imagine building a huge water desalination plant and only running it when there is excess power available on the grid. I can't see anyone wanting to invest in that, except maybe a financially myopic government, and they tend not to last very long.
    - 10y ago

extrapickles 10y ago

You can do things with the excess power that otherwise would be un-economical to do during a cloudy day. Things like smelting aluminum, desalinating water, etc take massive amounts of power.

TheSpiceIsLife 10y ago
You can't just do those things when the weather is good. Not without huge tax breaks to incentivise load following, because intermittent production of large scale industrial processes is hard and not cheap.
- extrapickles 10y ago
  They already do this without any gov intervention. The local steel recycling plant only operates when power is cheap. While they do need some advance notice to make sure they have enough people to run, they probably can get a good enough idea from a weather forecast (power here is mostly hydro with a dollop of wind and fossil). Some processes are better fits than others. If you have 2-5x extra capacity that is sold cheap on sunny days, someone will figure out how to use it.
  - TheSpiceIsLife 10y ago
    Do we have any numbers on what it means that they run only when the power is cheap? Does that mean they can operate in 4hr windows? Or do they run have to run the furnace for a minimum period? A large quantity of steel takes a large amount of energy to melt.
    - maxerickson 10y ago
      Interesting question. Brief research says the cycle time is ~1 hour (or less): http://www.steel.org/making-steel/how-its-made/processes/processes-info/electric-arc-furnace-steelmaking.aspx http://www.steel.org/making-steel/how-its-made/processes/pro... It could also be a plant for shredding scrap, where I guess it wouldn't be a time issue so much (and if it doesn't have the material inflows to run full time, timing cheap power would make sense).

petre 10y ago

> Where do you propose to put the excess power during sunny days Heat up some molten salts or any phase change material, then run the steam through a generator. Or pump water uphill. Not very efficient but doable.