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I presume by "renewable" you really mean solar and wind. Hydro is generally pretty cheap, but also mostly tapped out. With that in mind, renewables are often mo
by travisb 5y ago
I presume by "renewable" you really mean solar and wind. Hydro is generally pretty cheap, but also mostly tapped out. With that in mind, renewables are often more expensive for consumers due to a combination of a few factors:
1. The sun doesn't shine at night and the wind doesn't always blow strongly
2. People want to use power at all times of the day
3. Fixed costs in fossil fuel electricity generation are non-trivial
4. The utility scale electricity storage story is dire
The result is that renewables need to be overbuilt compared to their nameplate capacities to make up for less-than ideal weather and expected daily and annual weather cycles. I've heard those renewables produce something like 30% of their annual nameplate where a coal or gas plant will produce 90+%.
This overbuilding then ruins the wholesale price of electricity during high production times. For example, on a bright sunny spring day solar might push wholesale spot electricity prices negative. So the generating companies don't make as much money as you would expect from looking at average wholesale prices.
But people still want to use power after the sun has gone down and even if the wind has stopped blowing. So those generating companies need generating capacity to fill in that several hour long gap. Utility scale power storage in batteries isn't anywhere near being able to affordably store several hours worth of electricity. Also a cloud can roll across quickly or the wind might die suddenly. Therefore that backup generation is almost uniformly natural gas turbines because they can spin up and down quickly.
But even if no power is being sold by those plants, they need to be kept running to be instantly ready. So they are constantly burning some fuel to keep hot and spinning. The maintenance hours still keep racking up. There still needs to be people working 24/7. The costs of all that "idle" time need to be made up in the twelve hours of active generation.
So you end up with essentially double the generating capacity, half solar/wind half natural gas, and are continually paying the costs for both. Obviously that's going to be more expensive than simply burning a bit more fuel to run the natural gas plants near capacity full time. Or even build more efficient base-load plant types like coal or nuclear which have troubles scaling up and down quickly enough to balance out changeable renewable generation.
- froh 5y agoRenewables need buffering capacity, indeed https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectricity https://en.m.wikipedia.org/wiki/Pumped-storage_hydroelectric... Or decentralized battery packs.
- aaronblohowiak 5y agoHow does psh compare to electrolysis and burning hydrogen?
- ncmncm 5y agoMassively more efficient. But when you have a lot of hydrogen synthesis capacity, it can keep working to produce valuable industrial product when the tanks are full. There is a large and fast-increasing demand for hydrogen.
- julosflb 5y agoCapacity factor of latest floating offshore wind can be as large as 57% (https://www.equinor.com/en/news/20210323-hywind-scotland-uk-best-performing-offshore-wind-farm.html https://www.equinor.com/en/news/20210323-hywind-scotland-uk-...). 30% is typically what you get onshore.