Something I firmly believe is that there’s a ton of low hanging fruit for timing our energy use better. It is just hidden by the desire to present a uniform energy price.

Like why not run our water heaters when power is cheap? Then if that became a thing, we might even be interested in larger water heater tanks. Batteries cost per volume, you only pay for the surface are of a metal tank!

It's quite fun (and educational) with the kids to work out when to put the car on to charge, when to run the dryer etc, looking at the few days ahead forecasts.

Last month, we paid 11p per kWh on average, which is less than half what you'd pay on a standard tariff, and it's nice to be doing something good for the environment too. It's particularly satisfying to charge up the car when tariffs go negative.

Here's today's rates (actuals): https://agilebuddy.uk/latest/agile

Here's a forecast: https://prices.fly.dev/A/

Somebody has to go and turn it off, and having this person available overwhelms all of your operational costs.

Or alternatively, you need the infrastructure to do it automatically, what is currently expensive. (But there aren't intrinsic reasons for that being expensive, it's probably due to lack of scale.)

If it's just slightly negative, or just rarely so, it's not worth it.

The solar+battery revolution is doing for power what cell phones did for communications in the third world in the 90's and 2000's.

[0]: https://www.eesi.org/papers/view/fact-sheet-proposals-to-red... [1]: https://www.instituteforenergyresearch.org/fossil-fuels/rene...

https://www.whitehouse.gov/wp-content/uploads/2025/05/Ending...

China's numbers did rise quickly on that measure and is above the EU now I think but still way below the US.

And if you don't like per capita, then China with 4x as many people is still behind the US when you compare cumulative CO2.

A third solution is to pipe it across timezones using HVDC and accept some level of efficiency loss and some geopolitical risks.

A fourth solution is to mix lots of wind, which performs better in winter and cancels out the lower insolation.

Realistically it's going to be all of the above, with the balance determined by local factors.

Something sad about that, really.

Which utility and plan is this? I'm not aware of any California residential rate plans that charge you for putting power back on the grid, much less $100/month.

That said, wholesale electricity rates are set by high frequency supply/demand markets.

Recent residential net metering rates are closely aligned with wholesale supply/demand based rates, so most utilities will compensate your brother in law near $0 when you are pushing power to the grid when wholesale rates are <= $0, because there are not enough buyers of the power he is generating.

He is using the grid as a battery, which comes at a cost.

This is of course changing as more grid connected storage comes online and creates demand for off peak electricity. In that case, you actually get paid for selling power back to the grid during high grid stress periods. I get paid a few hundred dollars a year in CA for doing that with my measly home backup battery.

Oh yeah, yes, after paying all the money to get the electrical hookup he doesn't want or need - yeah, he's gonna be on the hook for around $100/month.