| > Where it's cheap/possible to build, you mean. It's very uneconomical if you don't have any appropriate geological formations nearby. No, they don't need to be "nearby" anything, except for a high voltage transmission line. Pumped hydro reservoirs can be located anywhere there is adequate transmission. For example, the largest pumped storage facility in the U.S. stores energy for the entire PJM grid, which spans a dozen states. > Ok, fine. "This term is used by evil people" doesn't change the problem of "we need cheap storage to completely switch away from carbon fuels, and we don't have cheap storage" or even "we need power on calm nights". No, we actually do have cheap storage. Like I said, pumped hydro is cheap, and is currently available in quantities sufficient to render intermittent sources "dispatchable" in many regions. In addition, the price of battery storage is plummeting; large battery facilities are currently saving utilities millions of dollars just by regulating frequency. Many U.S. utilities are incorporating battery storage into major plans this year. This trend will accelerate. > Pretty sure that "dispatchable" means "not wind or solar" [0] and generally simplifies to "carbon, nuclear or hydro" You misunderstand the concept of dispatchability. It more usefully describes a system, rather than individual energy generators. For example, a nuclear power plant is pretty much the opposite of dispatchable, since it takes days or weeks to spin one up from idle. But pair it with a storage facility and the system gains the ability to sink surpluses and match loads. This works just the same with intermittent sources like wind. The only truly dispatchable utility-scale generators are diesels and particular kinds of gas turbines, such as the GE 7HA, which will continue to be useful as peakers. However most gas plants take hours to spin up, and these are quickly becoming less economical than renewables+storage. For example, next year the Inland Empire power plant, a large gas plant in CA with at least two decades of life expectancy remaining, is going to be demolished because it has become uneconomical to operate. Guess what's replacing it? |