When Sunrun got started, no one wanted to issue loans for residential solar. It was a new unproven technology, and the accounting departments at places big enou

When Sunrun got started, no one wanted to issue loans for residential solar. It was a new unproven technology, and the accounting departments at places big enough to provide these kinds of loans at scale just didn't know how to factor the risk. The article calls these TPO's, but in the industry the more common term is PPA's -- Power Purchase Agreements. That's more how large solar farms work -- they find a buyer willing to pay a fixed price over 20 years and use that contract to raise money in the capital markets. Sunrun kinda took that model and applied it residential, because that's what the financial industry that could supply the capital knew. Now that we're a few more years into this grand energy transition, PPA's are falling out of favor. Now that the capital markets see this home solar thing is more or less as reliable as promised, has expected depreciation, etc., personal loans are becoming the more common way of buying home solar.