[bad_alloc]

> What's the waste?

Any conversion from electrical to chemical energy is inherently lossy, and Methane would need to be burned later to release the energy. In general the less conversions needed, the better.

> More available than the air?

The air is 0.04% CO2, which in turn is mostly oxygen by weight. The biosphere is a much larger source and is self-recycling.

> WHY of this seems pretty clear to me.

I also got quite jaded and often see this at some attempt to save fossil-burning infrastructure, instead of truly adapting out energy use. For example maximizing use during the day and relying on a much smaller store in batteries, hydropower or heated salts at night. The premise of "energy anytime" might hurt us a lot.