U.S. Bancorp and National Cooperative Bank in Washington, D.C., have jointly financed a $64.4 million fund to help a California company build eight solar projects.

The solar installations, some of which are already underway, will be in Massachusetts and half of them will be in municipal landfills, according to Borrego Solar Systems Inc., the San Diego company that announced the deal Tuesday. Altogether, the eight projects will be capable of providing more than 18 megawatts of power.

National Cooperative Bank, an FDIC-insured savings bank with assets of $1.6 billion, provides banking services for cooperatives and socially responsible organizations. It said it contributed $31.7 million in construction financing to Borrego's new fund.

Minneapolis-based U.S. Bank would not disclose its portion of the $64.4 million investment but confirmed that it's a renewable energy tax credit investment. Borrego itself also contributed to the fund, a U.S. Bank spokeswoman said.

U.S. Bank is an active solar investor and it's the bank's fifth deal with Borrego Solar. In February, Borrego announced it had closed a $47 million renewable energy investment tax credit equity fund with U.S. Bank and East West Bank to build solar projects in California and Massachusetts.

In June, U.S. Bank announced its latest venture with San Mateo-based SolarCity Inc., a company with which the bank has done several deals.

U.S. Bank has invested more than $700 million in renewable energy projects, mostly for solar.

Borrego Solar has developed and installed solar systems in California, New England and the Mid Atlantic. One of its specialties is a solar financing package that enables organizations to get involved with solar energy without having to fund new projects themselves, via power purchase agreements. Power purchase agreements are long-term contracts to buy electricity at a predetermined rate.

Jennifer Bjorhus • 612-673-4683