The document discusses various models for financing clean energy projects. It describes programs that provide unsecured loans for home energy upgrades through partnerships with contractors. Larger secured loans may also be available. Loan terms typically range from 2-10 years. Interest rates are usually between 0-8.99% with some programs offering lower rates. Credit enhancements like loss reserves help mitigate risks. Successful programs tend to be simple, accessible through contractors, and have flexible financing options tailored to different project sizes and sectors.