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Without storage, you want a gas turbine to complement renewables. Having a large capacity in the form of gas turbines that is only use occasionally costs money

by phicoh 5y ago

Without storage, you want a gas turbine to complement renewables. Having a large capacity in the form of gas turbines that is only use occasionally costs money, but has to advantage that all extra renewable energy results in less use of gas and therefor less CO2. So today, we can have a grid that consists of renewables plus gas turbines without any storage.

pfdietz 5y ago
And even tomorrow, if the natural gas is replaced with hydrogen. A combined cycle gas turbine power plant might cost 10% of a nuclear plant of equal output. So even if we have to back up the entire fricking grid with CC it's still much cheaper than doing it with nuclear.
- phicoh 5y ago
  The problem with green hydrogen, is that producing hydrogen from electricity and then putting the hydrogen in a gas turbine to produce electricity is extremely inefficient. So a windfarm backed up by hydrogen may need a significant fraction of the farm to produce hydrogen. In the end, a nuclear power plant might be cheaper. Might be, because we just don't know. Nuclear power plants are insanely expensive at the moment.
  - pfdietz 5y ago
    Yes, it's inefficient. But not much of the grid's energy flows through that path, so the inefficiency doesn't cost you much. For long term storage, or rare outage storage, you want storage with low per-kWh-capacity capital cost, even if that means lower efficiency. And no, nuclear isn't cheaper, even if during the rare times you're burning hydrogen the cost/kWh is high. That's because nuclear needs to be selling at high prices most of the time, including when solar/wind/batteries are able to directly deliver. It's possible other technologies (transmission, demand dispatching, other storage technologies, even natural gas with atmospheric CO2 capture) will be cheaper than grid hydrogen storage. That doesn't help nuclear.
  - ZeroGravitas 5y ago
    It's fine as long as you don't do it when you don't need to. You build more renewables than you need for electricity production and use it to generate hydrogen for agriculture and industry 99% of the time. When you really hit the yearly peak you can a) turn the electrolysers off and if that's not enough b) use some of the hydrogen to generate electricity. Of course, if you're lucky, then you can get by with just the renewables and sell all your hydrogen for other uses but when that 1 in 10 year event happens you can get away without burning too much fossil gas and paying the carbon fee associated with it.

by phicoh 5y ago

pfdietz 5y ago

And even tomorrow, if the natural gas is replaced with hydrogen. A combined cycle gas turbine power plant might cost 10% of a nuclear plant of equal output. So even if we have to back up the entire fricking grid with CC it's still much cheaper than doing it with nuclear.

phicoh 5y ago
The problem with green hydrogen, is that producing hydrogen from electricity and then putting the hydrogen in a gas turbine to produce electricity is extremely inefficient. So a windfarm backed up by hydrogen may need a significant fraction of the farm to produce hydrogen. In the end, a nuclear power plant might be cheaper. Might be, because we just don't know. Nuclear power plants are insanely expensive at the moment.
- pfdietz 5y ago
  Yes, it's inefficient. But not much of the grid's energy flows through that path, so the inefficiency doesn't cost you much. For long term storage, or rare outage storage, you want storage with low per-kWh-capacity capital cost, even if that means lower efficiency. And no, nuclear isn't cheaper, even if during the rare times you're burning hydrogen the cost/kWh is high. That's because nuclear needs to be selling at high prices most of the time, including when solar/wind/batteries are able to directly deliver. It's possible other technologies (transmission, demand dispatching, other storage technologies, even natural gas with atmospheric CO2 capture) will be cheaper than grid hydrogen storage. That doesn't help nuclear.
- ZeroGravitas 5y ago
  It's fine as long as you don't do it when you don't need to. You build more renewables than you need for electricity production and use it to generate hydrogen for agriculture and industry 99% of the time. When you really hit the yearly peak you can a) turn the electrolysers off and if that's not enough b) use some of the hydrogen to generate electricity. Of course, if you're lucky, then you can get by with just the renewables and sell all your hydrogen for other uses but when that 1 in 10 year event happens you can get away without burning too much fossil gas and paying the carbon fee associated with it.