alt Hacker NewsCan confirm, setup a couple hundred watts as a hobby project during the pandemic and built a battery pack - the biggest challenge (other than matching connectors) is finding anything other than just "charging devices" that the thing is practical for - until you get up around 1000W a lot of "normal" stuff is just too hungry.
This just plugs into an outlet and offsets whatever usage you have, though. No need for a battery or matching load. It just subtracts 180 watts from your household usage.
These types of devices are fairly popular in Germany, and maybe other places. For someone like me, with very high peak daytime prices, even a small offset would be valuable, but the full price here seems to be $500, which is too much. No reason it couldn't be much cheaper, though.