Tioga Energy, a San Mateo, Calif. company that facilitates affordable power purchase agreements between solar energy generators and commercial, government and non-profit consumers, has raised $1 million in debt and rights, according to a filing with the SEC.

This type of power purchase agreement allows energy providers and consumers to agree to a rate that is compatible with or less than market rates. Tioga goes as far as to install and maintain rooftop solar panel systems or other solar properties. Its customers do not pay for either of these services, only the energy generated in the form of a long-term fixed rate. These agreements are becoming increasingly popular -- now covering up to 75 percent of newly-installed solar systems.

Tioga last raised capital in 2007, closing a $14 million first round of funding from Nth Power, Draper Fisher Jurvetson, NGEN Partners, Rockport Capital Partners, Kirlan Venture Capital and DFJ Frontier.