Gas Turbines
 

and speaking of GE...

besides Chainsaw Jack, the other problem GE had was the big bet on gas turbines for power production - they DO have a lot of adv.s but got killed as a mainstream effort by renewables

but they work great for load balancing

https://pv-magazine-usa.com/2020/03/02/morning-brief-ge-completes-first-battery-energy-storage-assisted-black-start-acciona-to-invest-4b-in-pv-and-wind/

gas turbines are among the most amazing of inventions...bordering on witchcraft in power production.

IIRC, you can get 65%+ efficiency from a combined cycle gas turbine


and BTW, NG puts half the carbon into the atmosphere that coal does

Killed? I don't think so. Last time I looked there were somewhere between 1500 and 2000 NG power plants in the US, and NG produces the lion's share of electricity here. If that's not "mainstream" I don't know what is.

So, I don't see it going anywhere anytime soon...especially when NG turbines are basically a compulsory component for any wind/solar farm as an efficient form of co-generation.
The energy density and capacity factor of a modern NG plant makes large-scale wind and solar a complete non-starter, IMO (with Nukes even better).

GE made a big bet on NG turbines, and that helped kill them (not the turbines)

You can get above 80% in a Cogen application. Only the "H" class can exceed 60%, but they are too complicated to sell.

The "F" class can easily exceed 50% thermal efficiency, lower heating value.

I expect gas turbines will be the main power generation machines for the next 30 years as renewables slowly take over and steam plants (coal and natural gas) age out of competitiveness. If you look at power generation sources over the last 20 years, natural gas powered plants have steadily grown while coal has nose dived. The vast majority of new gas plants are gas turbines (simple, combined cycle, and co-gen) since almost nobody is building new steam generator gas plants. Renewables have been growing at exponential rates for several years but even at that rate it will likely take 20 years to become the majority source.