[trymas]

That puts a great perspective, though please correct if I am wrong - if you are testing power supplies - you need to dump that power somewhere?

Can’t you dump it back to power grid (easy to say, probably not so easy to do)? There will be losses, but better than nothing.

[rootusrootus]

Or just don't draw it from the grid to begin with. Test enough really big power supplies, and the cost of a big set of batteries & inverters starts to look like a good investment vs paying the electric utility for it.