And the same thing for residential scale is literally just a ceramic space heater running at ~1500w.
They're dirt cheap, usually have temp safety checks built in, work on a residentially sized circuit, and are available everywhere.
I needed a cheap and consistent load to do LFP battery testing, and I could spend $5,000 for a real test unit, or $21 for a ceramic heater that will do basically the same thing.
If you've already got the monitoring for the batteries/inverters, a heater is a GREAT load choice.
I'm not sure that this really is a completely off-the-shelf stove element. But obviously, the technology is basically identical to what you'd have on your stove.
A neat example of regenerative braking being important is the London Underground: they've had a persistent problem with high temperatures in the subway, of which a decent % is actually heat from trains braking. By using regenerative braking rather than putting that energy into the tunnels as heat, they can transport that energy outside the tunnels, keeping them cooler.