“make green hydrogen“ Which requires a machine which may or may not be the cheapest to do keep available for opportunistic "power2somethinguseful". Batteries a

“make green hydrogen“ Which requires a machine which may or may not be the cheapest to do keep available for opportunistic "power2somethinguseful". Batteries are also in this category, they excel in how many watts you can dump per dollar worth of battery (before they are full), but don't offer many Wh per investment. Which brings us back to what GP wrote: "What matters is to build the cheapest possible machine, to make use of the energy in excess." It's all about how many hours of opportunistic activity does it need per year to be worthwhile. If you build some super efficient power2useful machine that is only worthwhile when running 24/7, then you are exactly zero steps closer to the green energy future. The key metric is where on the opportunisticity spectrum between 24/7 on one end and only the few most energy-abundant hours per year on the other end a technology can place itself. At the opportunistic extreme end of the scale we will undoubtedly find resistive boosters to latent heat stores that usually run on heatpumps alone (boosters come online when maket price drops below the heat pump's buy threshold divided by work factor)