We have the excess electricity already, but I’m not yet at the legally required amount of solar panels.

At work we are investing in energy storage, both batteries and heat storage and looking for more solutions.

For any but the largest commercial solar/wind providers, batteries and heat storage (or cold storage actually too!) are the best uses of overproduction of electricity. Batteries at your location are 90%+ efficient round trip, meaning for every 1kWh you shove into the battery, even after all the conversion and storage costs, you’ll be able to get 900Wh or more out of the battery when you have a use for it. Many PV tied batteries are upwards of 97% efficient even!

Heat storage is another great use, whether in water (to mitigate need for new energy expenditure to heat water for use), or in thermal batteries for space heating. Although the biggest downside to thermal batteries are their size. If you’ve got spare space then they can be effective in a home or business.

I’m looking at hydrogen, because it’s known tech and I dream of finding a way to use it in a more stable chemical form for storage.

I did the same looking at Hydrogen, and its pretty bleak. Not only is creating hydrogen safely (from electrolysis) difficult, but storage is a nightmare. Any kind of gaseous storage is incredibly difficult because of how small a molecule H2 is, and if you’re storage is inside a building that leakage creates explosion risks.

The safest way I saw to store and consume hydrogen is absorbed into a metal hydride. The problem there is that fillers (because of pressure) are expensive $2k for the cheapest one I saw, and you need many metal hydride cylinders to store any appreciable amount of hydrogen. So they end up being large, heavy and bulky or relatively little energy storage.

For home use, a regular lithium battery is so much more efficient and safe.