More than 50,000 California households have signed up for Property Assessed Clean Energy (PACE) financing since state legislators passed a law in 2008 allowing residents to borrow money for such things as solar panels and energy-efficient windows. The financing method, authorized by cities and counties, and funded by venture capital-backed startups like Renovate America Inc, Renew Financial LLC and Ygrene Energy Fund Inc, is then paid off through special assessments on property tax bills.