It would be pretty tough to get exposure to solar panel equity by any means - aside from providing a great experience, we actually will be pretty much the next closest thing to owning solar panels if you don't have a suburban home.

We are different from investing in a utility for two reasons. First, you'll own simple direct ownership in a panel, not in an entire organization and all its bureaucracies and stakeholders. I want it to be as close to a consumer product as possible, to feel personal, not like an investment. Second, you panel will slowly depreciate over time and eventually be liquidated where a utility is hypothetically perpetual.

Aside from that, utilities typically pay $.04 or so for power generated. We'll likely have a behind-the-meter arrangement with a commercial power purchaser (like a factory or hospital), which can boost the return but be somewhat more risky.

So... worse in every possible way, and you want an emotional connection to replace return on investment.

Nearly all public utilities are traded on the open markets. In the normal course of things, the minimum investment is either one dollar (if your broker supports fractional share trades) or one share (generally less than $200: there are few companies that like to follow Berkshire Hathaway's practice).

None of them, to the best of my knowledge, are currently planning on being 100% solar. It's unlikely, although a 100% renewable company is pretty likely to either now exist or happen shortly. Hydro-Quebec is, courtesy Wikipedia:

hydroelectricity (96.78%)

wind (2.16%)

biomass, biogas and waste (0.75%)

nuclear (0.19%)

thermal (0.12%)

I haven't looked into solar panels but I have some money invested in a 'wind infrastructure fund' which perhaps is the kind of thing you'd be interested in. Market cap of £2.5bn

https://www.greencoat-ukwind.com/