I've been chatting to another user on here (https://slrpnk.net/u/JacobCoffinWrites who does the cool photobash images of solarpunk scenes) and it really got me thinking about solar concentrators so i went on a bit of a binge learning about them, there are so many really cool designs and so many things a source of heat like that can be used for.
One idea i especially like is using it to power absorption refrigeration (like off-grid gas powered refrigerators use) so when the sun is hot you can focus it's power and use it to cool your house -- then when it's starting to get cooler switch it to heating, ideally heating a medium which will retain the heat so you can distribute it through the night. For agricultural use it could heat greenhouses and drying rooms, industrially there's an endless amount of possibilities. Even recreationally it could be great, cutting out the cost of heating a pool or hot tub - could really make some off-grid luxury.
A great youtube channel with various diy examples is Sergiy Yurko, who's still managing to make great videos despite living in Ukraine - https://www.youtube.com/@sergiyyurko8668/videos
and https://www.youtube.com/@GREENPOWERSCIENCE/videos has some really cool videos too, like demonstrating using a fresnal lens to melt metal
I really like the range of possibilities you're considering - especially for options for replacing the highest-power-consuming appliances, especially those which only use the power to produce heat. I've got a plan for a scene of a workshop that'll use one, but I think first I want to try a solarpunk kitchen.
I'm also thinking about trying to get my anvil back from a friend, buying a fresnel lens, and building a frame for it with a fire pot built in at the focal point, and seeing if I can use it like a solar forge.