Asklemmy

You can try a swamp cooler, which works best when it's not as humid, put a beach towel or blanket over an open windown with it's end in a pot of water, so the water soaks up through it. The evaporation produces a cooling effect. Try to put one in a window the air is coming into.

Create shade wherever the sun shines, on the outside before the sun even hits the house. Focus especially on shading the glass and metall parts of your house. Make it angled and with some distance from the house so it still allows air flow. Mesh will shade less but allow more airflow and tarp will block pretty much all wind byt also pretty much all sun, so experiment with the tradeoff for different parts of the house like near windows or over the roof.

Where I live that's enough to keep me reasonably, so thats all I know. Probably need to learn more with the more extreme weather we have now.

Yer I'm in Oz so no shortage of sun here lol

Yer, that's the perfect getting in the way of the good problem, are old car batterys as good as 2v deep cycle ones? no, but there still fine to use if you have nothing else. Are you gonna run a whole house off em? No, but I ran my fridge, tv, lights and a small water pump most days up till about 11pm off I think about 12 old truck batterys,

Umm around 2022ish, the solar panels were free from the tip, the batteries were also free form a mine site(collapsed cells could hold 12v but couldn't crank out high amps), solar controlers were from eBay 150 bucks or something and a 5000w inverter was 600ish from memory also probably about 200 bucks worth of battery cable and connectors,

In rural china their farms traditionally have one, like a tank they route sewage and scraps and whatever, and they pipe off the gasses for cooking and heating and such, as it produces methane and the like.

you can use an anaerobic digestion system to generate about 100 liters of gas a day, given that you feed it around a liter of 50/50 food scraps and water slurry. you can heat a stirling engine with it to generate 2-300W or so.

it's not risk free of course, biogas is explosive, but taking precautions can minimize it. produce and store outside, under low pressure, limit the volume, and use filters and flame arrestors.

this video is a good intro to the subject.

another interesting avenue if you have access to cheap wood is syngas. you can run clean syngas in a unmodified internal combustion engine, so the generator part is easy. clean gasification is the hard part, since you need to get rid of the tar and water content. using charcoal is the best method because all that gunk is already burned off. you put it in an airtight container with an inlet and an outlet, light it at the inlet, and pump in a controlled amount of air. the charcoal then goes through a redox reaction and produces syngas at the outlet.

a syngas generator can produce roughly 10x the energy of a biogas plant of the same size, but involves high temperatures and more preprocessing.

here's a video on that too.

lastly, what's more important to you? lowering your bills or being energy independent? my housing co-op has a deal with a local electricity company where they installed a load-following battery bank in our basement. it tracks the energy market so it can charge at night, be used by us during the day, and sell the surplus to the grid. it has lowered our energy bills by about a third. a lot less messy than the other two solutions, but also a lot less independent. doesn't really matter for our situation, since we're on district heating as well, but your situation may be different.