How to utilize excess energy in remote areas

My father has a small house in southern Spain. There's no grid so we put loads of solar panels (8kW). In summer, there's plenty of energy.

I have installed 3 servers (a "normal" tower PC + graphic card) running Boinc. A small timer powers on the PCs at 10, and powers them off at ~17h. Once up, they start folding and calculating for Folding@Home or WorldCommunityGrid.

I don't earn any money from it, but I like the fact that I'm contributing to science

I find this question to be quite flawed. We perpetually fail to consider that forming the grid is a real-time interconnected machine. There isn't really any excess energy, unless you are storing excess energy (e.g., in batteries, etc.). Otherwise, because we're working in power, you're just not generating what you're not using. That's the concept of spinning reserve, you're just not running full-tilt: https://en.wikipedia.org/wiki/Operating_reserve

If we insist on answering the question as-is: if you have a big area with large potential to generate electricity, just build the power resource and connect it to the grid, and bid on the local real-time & futures power market in your interconnection region. If the numbers don't look good for you, maybe you can mine crypto, but in reality you'll actually get a better return on your investment by investing in energy storage and playing the market with your generated energy to shift its use to peak times on the grid.

This isn't the answer that people are suggesting, because it's not glamorous.

On a smaller scale, I’m on off-grid solar and I potentially have 20kWh excess generation a day on solar (+/- 100%). Any exciting ideas regarding what I could shove that into?

Carbon Capture and Hydrogen Electrolysis will make Syngas (methan + CO ) Which can be formed into multiple organic compounds (fuels, etc) It seems like the capital costs is something like $0.75 per gallon of gasoline on a respectable scale. (skylon study). The electrical cost is where the real cost of synfuels.

Or, on a small scale, you could charge an electric car. :)

Electrowinning scrap metals to purify them? Electric kiln for pottery? Crushing rocks into gravel?

As renewables drop in price, the connection becomes a greater part of the cost.

I don't think this will make long term sense as a result.

You really want places with sun, and wind, and good grid connections to industry with power needs to make the most of the opportunity and then you can make green hydrogen to export as well, but that also requires good transport connections.

That export opportunity currently depends on legislation though as current alternatives beat it on price if they're allowed to ignore their externalities.

Power to Gas. Use the electricity to make hydrogen and then ammonia. You will need water though…but not that much.

Melting and mining nearby resources.

Renting out remote controlled streaming geofenced battery charging model cars.

Autonomous radio telescope.

Mining crypto. There's no issues with burning energy that would otherwise go to waste anyway.