We can focus wholly on the food and chat and reconnect with family or friends over food which is way more mentally satisfying than binging over something and not paying attention to the environment.

OK - I couldn't stand the thought of buying something, so I just filled a quart container full of water and put it in the toilet tank to displace some of the water.  And the toilet flushes fine - so I think that's a good low tech fix that pretty much everyone in my region could use.  We also don't flush when we pee, because we are in a drought.

Wave and tidal energy have a lot of problems, it seems - if you build big concrete dam-like structures, silt accumulates, and there are a lot of problems with building. I had hoped this might be the solution to the duck-shaped curve of times that solar energy is not avalable, but now I'm not so sure.  Maybe offshore wind is the solution for those times that solar is not available.

And a little more research I looked at "Swamp Coolers". They have units for single areas of about 500-700 sq. ft (my apt is 520 sq ft) for around $300-$500. Add 300watts of solar panels and a battery source with some installation and I could have solar powered heating/cooling for maybe around $2k. I can share this info with my coop-mates who need a heater replaced. A standard methane wall heater is about the same price with installation.