The ability to reuse electronics for new purposes until they stop working to the point that they're irreparable or otherwise no longer fit for purpose. You can do a LOT with old computers and hardware, and you can often resurrect "broken" things relatively easily, if you can find parts. However, sometimes you do have to weigh this against the energy costs some old stuff has relative to new stuff if you don't have direct access to your own renewables.

My entire home network infrastructure is built out of old, repurposed, and/or second-hand equipment. My router is a broken netbook running OPNSense, my switch is an older Cisco small business switch. I picked up a used couple year old used consumer router and put OpenWRT on it and run it as a standalone access point. It supports Wifi 6, and I expect it to last at least a decade. The only thing I bought new was my modem a few years ago, because I refuse to rent from the ISP.

More directly relevant though is that I'm using an old low power (formerly) Windows 8 tablet from 2014 to run Home Assistant, which I'm using to optimize my energy usage bit by bit. It's a slow process because I don't want to run out and buy new stuff until existing stuff stops working, but I'm slowly expanding my network to observe my energy usage and put in place automation to reduce usage where it makes no sense to waste energy.

One thing I'd like to expand into is actually learning to solder and picking up some basic electrical engineering skills. So far this has mainly been hobbyist, replacing only parts with connectors. I'd like to be able to do even more.

I'm a cannabis grower.

Back when cannabis was a bit less than legal in my area, I grew indoors and learned how to grow a large crop in very, very tiny spaces. However, as was standard back then for covert growers, it was incredibly resource intensive.

Now that it is fully legalized here, I currently work in greenhouses on a large piece of land. I've now learned how to grow much more with so much less.

If the need ever arose, I'm confident that I could grow a very large amount of food, in very tight quarters, with minimal inputs.

I was once tasked with designing automated greenhouses that were supposed to be very profitable, which means that they would use little energy and little labor.

The project did not go forward but I still do think that small units of automated, local, efficient food production is the future. I don't think single-house size but maybe a dozen households could share one decently sized greenhouse and grow most of their plant-based needs.

Ive work for a company that develops irrigation equipment solely on water and solarpower. Also we work with smallholder farmere. I am able to learn also how smallholder farmers grow all different foods. To pump with waterpower and solarpower is a bit finiky compared with a fuel pump. We work towards removing the finiky and it is a rewarding goal and the work is very interesting.

That‘s hard, I currently work in SAP Basis (tech side) and I‘m not sure. In a solarpunk world, I feel like my job wouldn‘t exist, as it‘s really focused on the needs of "big business" and needs a ton of energy to run this whole system.

I‘ve been thinking though, things like supply chain, material management, etc seem like they might be useful to have open source for alternative organisations too and I found this: https://erpnext.com/comparisons/sap-alternative though idk how good any of this is truly and I‘m not sure how it would serve solarpunk, I‘m still too new to all this and only work with a small part of it, though it does seem to be the brain of business.

Before that I worked as a System Engineer, for a fossil fuel company… there I learned that the interests of such a company and anyone who wants nature to survive are incompatible, as they were greenwashing things in marketing while lobbying against any change and toasting to their profits behind closed doors. It made me feel like a monster.

Sorry if none of this is useful, I‘m mostly here to learn more about solarpunk from you guys cause I‘m so negative from my experiences and I want to change that towards a more hopeful perspective.

I learned efficiency in heat transfer by opposite current flows. For example, a heat trade between outside air coming in, and inside air blowing out is most efficient if the highest temperature has the exchanger with the coldest temperature, and second and third stages of exchange always move so that the last exchanger have both sides closest in temperature.

If you want to squeeze the most that you can in a passive system, this principle will help.

Don't forget, in insulating, you want the least transfer, so you go in the opposite direction.

I don't know if I have an answer to this yet, but I wanted to comment to say this is a great question, OP. Thanks for asking it; there's some really interesting stuff in the comments

I know a fair amount about infrastructure. There's A LOT of stuff under the ground you probably never even think about.

I'm a repair engineer for lab equipment. There's not specific fact that comes to mind, but I find myself thinking about gratifying it is that the job itself fits perfectly well into a solarpunk future.

You could remove the monetary demands of capitalism and in a day-to-day sense my job would still make sense. I spend my time driving to various job sites and labs where they need help setting up robotics and sample analyzers and things.

I think the main thing it illustrates is how fun and productive a solarpunk lifestyle can be. It reminds me of how my mom paid her way through college as a bike courier in DC (right during the Watergate years). I love jobs where you have to go on quests.

I work in a tech role for a big tech company, so at first glance, not much. I like to believe that I'm good at planning stuff and figuring out how many hours by how many people it should take, which is a good skill for all kinds of issues.