Here are a few things to consider when wading into energy efficiency finance:
1. Returns to energy efficiency upgrades accrue out of negative cashflow (money not spent), which means its hard/impossible to put a legal "box" around the financial returns to the project, contra solar investments, where there is a meter and it's usually possible to slice and dice who gets what.
2. Energy efficiency upgrades also pose a problem with respect to collateral. In our case, although we had the right to take back our LED lamps, the value of what we got back, even in the best case, would have been negligible. Most EE upgrades are even less inviting as collateral, like insulation or HVAC upgrades.
3. There are simpler, but more balkanized (i.e., different not only from state to state, but even utility to utility, or city to city) financial incentives for energy efficiency upgrades. This poses a challenge for finance as a differentiator for energy efficiency. Simpler incentives mean the value of a third-party financier who abstracts away these problems is less valuable; and more balkanized incentives mean that is harder in any case for a third-party to offer solutions that scale geographically. Again, contra solar, where the federal tax incentives mean that it’s almost necessary for a third-party with tax equity appetite to finance a portion of the investment, and since it’s at the federal level it scales across the US.
My advice would be to do some careful thinking about how and why your financial offerings are better than what you could do financing them on a credit card or through a normal bank loan.
In addition, I would put some serious thought into whether or not finance is the true barrier for energy efficiency projects. Again unlike solar, these things are inside the home/office/whatever, not outside, so bring up aesthetic concerns as well as comfort concerns. Other things, like HVAC systems, are usually replaced when they break.
Anyway, I hope this is useful and that you get a lot of projects done!