4 ms·

It is not possible (with today's energy tech) to operate a power grid 24x7 on renewables alone (no storage). See https://www.manhattancontrarian.com/blog/2019-

It is not possible (with today's energy tech) to operate a power grid 24x7 on renewables alone (no storage). See https://www.manhattancontrarian.com/blog/2019-3-14-how-much-do-the-climate-crusaders-plan-to-increase-your-costs-of-electricity-part-iv https://www.manhattancontrarian.com/blog/2019-3-14-how-much-... for a good overview

Retric 8y ago
That was written by someone that clearly does not know what they are talking about or was simply lying. Many off grid systems operate by having excess solar and minimal storage. “storage for what could be many days — or even a month or more — of power.“ The only way you get that kind of assumption is to set production at exactly as much energy as you need over the year. If you produce extra power every day then you never need even 1 day of full storage. It’s true wind and solar does not always produce the same amount of power every day, they never produce zero. Thus, it’s a question of what you scale the system around minimum or average production over some time frame. Run the numbers vs. assuming minimum production and some storage is a net gain. But, as Nuclear costs at a minimum twice as much and also needs redundancy, actual storage requirements are fairly low. Those numbers get worse if you need run Nuclear as less than full capacity.
- gwright 8y ago
  Yes. You need that much storage because of the seasonal nature of sun and wind. You can't just assume a buffer of a couple of days or even weeks!
  - Retric 8y ago
    Again assuming 1 year of capacity is optimal is stupid, as renuables are really cheap. Aim to have a surplus on the lowest output day of the year and you never need more than a few hours.
    - gwright 8y ago
      All the studies I've read about indicate that much more storage is needed.
      - Retric 8y ago
        The grid currently has almost zero storage. Saying we should build several times as much storage seems to suggest we need a lot of storage. But, it’s relative to a very small baseline. 1 hour of storage would be a vast increase, but it’s 1/10th the cost of 10 hours of storage. So, you need an accurate estimate to work from. Further, the ideal amount of storage is heavily influenced by price and cost of production. The grid is a huge complex system and simple models don’t provide good answers.
        gwright 8y ago
        Power generation must match demand very closely and in real time. Demand is very predictable. As for supply, the generation capacity of fossil or nuclear power plants is known ahead of time and can be managed to provide power in a predictable fashion. These plants don't randomly begin generating more power when the wind blows or when the clouds part or the sun rises and they don't randomly generate less power when the winds die or the clouds arrive or the sun sets. You don't need storage mechanisms with this type of generating capacity. But if you try to shift significantly towards solar/wind to provide power you now have an unpredictable generating system. That can be mitigated to some extent by adjusting the output of the traditional plants but the more your generating capacity is moved towards the unpredictable renewables the harder it becomes to keep the balance. Even if you manage to keep things balanced, you can't decommission the old plants because sometimes (dark windless nights), your renewables aren't going to generate any power and most or all of the power has to come from those plants you were trying to replace with the renewables. The only way around this is to come up with some sort of storage mechanism that can react quickly to the varying supply of renewables to maintain a smooth/constant power supply. Which wouldn't necessarily be a problem except for the fact that we actually know how to build high-capacity cost-effective storage mechanisms.

Retric 8y ago

That was written by someone that clearly does not know what they are talking about or was simply lying. Many off grid systems operate by having excess solar and minimal storage. “storage for what could be many days — or even a month or more — of power.“ The only way you get that kind of assumption is to set production at exactly as much energy as you need over the year. If you produce extra power every day then you never need even 1 day of full storage. It’s true wind and solar does not always produce the same amount of power every day, they never produce zero. Thus, it’s a question of what you scale the system around minimum or average production over some time frame. Run the numbers vs. assuming minimum production and some storage is a net gain. But, as Nuclear costs at a minimum twice as much and also needs redundancy, actual storage requirements are fairly low. Those numbers get worse if you need run Nuclear as less than full capacity.

gwright 8y ago
Yes. You need that much storage because of the seasonal nature of sun and wind. You can't just assume a buffer of a couple of days or even weeks!
- Retric 8y ago
  Again assuming 1 year of capacity is optimal is stupid, as renuables are really cheap. Aim to have a surplus on the lowest output day of the year and you never need more than a few hours.
  - gwright 8y ago
    All the studies I've read about indicate that much more storage is needed.
    - Retric 8y ago
      The grid currently has almost zero storage. Saying we should build several times as much storage seems to suggest we need a lot of storage. But, it’s relative to a very small baseline. 1 hour of storage would be a vast increase, but it’s 1/10th the cost of 10 hours of storage. So, you need an accurate estimate to work from. Further, the ideal amount of storage is heavily influenced by price and cost of production. The grid is a huge complex system and simple models don’t provide good answers.
      - gwright 8y ago
        Power generation must match demand very closely and in real time. Demand is very predictable. As for supply, the generation capacity of fossil or nuclear power plants is known ahead of time and can be managed to provide power in a predictable fashion. These plants don't randomly begin generating more power when the wind blows or when the clouds part or the sun rises and they don't randomly generate less power when the winds die or the clouds arrive or the sun sets. You don't need storage mechanisms with this type of generating capacity. But if you try to shift significantly towards solar/wind to provide power you now have an unpredictable generating system. That can be mitigated to some extent by adjusting the output of the traditional plants but the more your generating capacity is moved towards the unpredictable renewables the harder it becomes to keep the balance. Even if you manage to keep things balanced, you can't decommission the old plants because sometimes (dark windless nights), your renewables aren't going to generate any power and most or all of the power has to come from those plants you were trying to replace with the renewables. The only way around this is to come up with some sort of storage mechanism that can react quickly to the varying supply of renewables to maintain a smooth/constant power supply. Which wouldn't necessarily be a problem except for the fact that we actually know how to build high-capacity cost-effective storage mechanisms.