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>> Renewable energy is getting so cheap that throwing kWh away can be cheaper than the cost of idling other capital infrastructure. That's missing the point.T

by mamon 6y ago

>> Renewable energy is getting so cheap that throwing kWh away can be cheaper than the cost of idling other capital infrastructure. That's missing the point.The problem isn't "what to do with excess of energy at peak times?", it's "where do we get energy from on quiet, wind-less nights?" Solar and wind are highly unreliable, so storing energy for is the necessity. Or we can use nuclear.

epistasis 6y ago
Who was making this point that I supposedly missed? Where we are in the conversation, your problem has already been addressed, and part of the solution has been to overprovision renewable generation such that we have excess electricity at many times, amounting to 50% to 200% of current electricity usage. The problem you discuss has been addressed with tons of predictions and models. It's solvable with excess generation capacity, storage, and transmission capacity. Which path we choose will depend on the relative dollar costs and political costs of each. (For example HVDC transmission would likely save us lots of money, but is so difficult politically that it is unlikely to happen.) But in any case, nearly all models show that under nearly all cost scenarios, we end up with lots of excess generation capacity, with curtailed renewables generation for a large chunk of time. This is the future we are talking about, a future where we are meeting our energy demands with all renewables, and we have lots of excess generation capacity with zero marginal cost.
- mamon 6y ago
  >> It's solvable with excess generation capacity, storage, and transmission capacity So now you're arguing FOR energy storage? Your previous post was basically: "let's overprovision and let excessive energy go to waste, instead of building costly storage infrastructure.".
  - epistasis 6y ago
    We will have a mixture of storage, over-provisioned generation, and transmission, the only question is the relative proportion. And that relative proportion will be determined by how quickly costs fall relative to each other. If a kWh storage costs 10x the amortized capital costs of a kWh solar generation, we will have a lot less storage than if storage only costs 2x the amortized capital costs of a solar kWh. If hydrogen electrolysis can become cheap in 2030, maybe we will even use hydrogen for some storage, but we will have to balance the capital costs of hydrogen generation and conversion back to electricity with everything else, which will determine how much of it gets deployed.
    - mamon 6y ago
      It's not only about cost, it's also about practicality: there is some baseline demand on electricity even at night. Solar obviously cannot fulfill that demand. Wind also can't because it is too unreliable. So we do need some storage technology, and hydrogen is one of the options. It seems way cheaper than using Lithium-Ion batteries, but might be still more expensive than, say, pumping water uphill and using that to power a hydroelectric plant. Energy transmission can be some solution here, but we might be forced to transmit energy across the continents (so, for example solar plant in Sahara delivers power to New York City at night) which probably is too costly.

by mamon 6y ago

epistasis 6y ago

Who was making this point that I supposedly missed? Where we are in the conversation, your problem has already been addressed, and part of the solution has been to overprovision renewable generation such that we have excess electricity at many times, amounting to 50% to 200% of current electricity usage. The problem you discuss has been addressed with tons of predictions and models. It's solvable with excess generation capacity, storage, and transmission capacity. Which path we choose will depend on the relative dollar costs and political costs of each. (For example HVDC transmission would likely save us lots of money, but is so difficult politically that it is unlikely to happen.) But in any case, nearly all models show that under nearly all cost scenarios, we end up with lots of excess generation capacity, with curtailed renewables generation for a large chunk of time. This is the future we are talking about, a future where we are meeting our energy demands with all renewables, and we have lots of excess generation capacity with zero marginal cost.

mamon 6y ago
>> It's solvable with excess generation capacity, storage, and transmission capacity So now you're arguing FOR energy storage? Your previous post was basically: "let's overprovision and let excessive energy go to waste, instead of building costly storage infrastructure.".
- epistasis 6y ago
  We will have a mixture of storage, over-provisioned generation, and transmission, the only question is the relative proportion. And that relative proportion will be determined by how quickly costs fall relative to each other. If a kWh storage costs 10x the amortized capital costs of a kWh solar generation, we will have a lot less storage than if storage only costs 2x the amortized capital costs of a solar kWh. If hydrogen electrolysis can become cheap in 2030, maybe we will even use hydrogen for some storage, but we will have to balance the capital costs of hydrogen generation and conversion back to electricity with everything else, which will determine how much of it gets deployed.
  - mamon 6y ago
    It's not only about cost, it's also about practicality: there is some baseline demand on electricity even at night. Solar obviously cannot fulfill that demand. Wind also can't because it is too unreliable. So we do need some storage technology, and hydrogen is one of the options. It seems way cheaper than using Lithium-Ion batteries, but might be still more expensive than, say, pumping water uphill and using that to power a hydroelectric plant. Energy transmission can be some solution here, but we might be forced to transmit energy across the continents (so, for example solar plant in Sahara delivers power to New York City at night) which probably is too costly.