[gridspy]

Perhaps not in a 100% world, though I'll give you the point that they are useful now.

In a 100% renewable world we would not be extracting or refining oil. Natural gas (used by these turbines) is a byproduct of oil drilling. Were we not burning the oil, the natural gas might be too expensive alone.

Also, in a 100% renewable world we would (by definition) have enough generation all the time - (covered by batteries and good baseload sources) that turbine power was no longer required to cover peak loads.

[rgmerk]

It's not clear (yet) what a 100% clean energy powered world would use to cover the last couple of percent of demand when loads peak and/or variable generation troughs for extended periods.

It'll be some combination of demand management (which isn't nearly as horrifying as people make it out to be), pumped hydro, long-duration batteries like iron-air, but also possibly burning hydrogen or hydrogen-derived synthetic fuels (produced by electrolysis when hydrogen is abundant) and/or biofuels in turbines.

[fpoling]

Somebody calculated that a home in UK needs 1 Megawatt-Hour battery to backup solar energy during the winter. I suspect in 10 years that may cost below 25K, a small fraction of the property cost.

[mannykannot]

There is a time- honored, straightforward way to deal with the last two percent problem, which is to overbuild by a couple of percent or so.

[pfdietz]

Or very long term thermal storage, as from standardthermal.com

This would also need some sort of turbine to convert back to electrical energy.

[mannykannot]

Particularly with the development of fracking, natural gas production is no longer a just a byproduct of oil production, and can be (and is) pursued independently. Nevertheless, I agree that we developing renewables should be our priority.