A megawatt is enough energy to power about 650 homes.
According to the city, Riverside has doubled its solar output and currently has more than 320 solar residential, commercial and city projects generating solar energy.
Businesses and residents can partake in rebate programs to assist offsetting installation costs of solar generation systems.
Two businesses cited by the city pushed Riverside over the 4 MW mark: Hamblins Auto on Cypress Ave. and Champion Lumber Company on Chicago Ave. both have 34.96 solar kilowatt systems.
According to the city, Riverside Public Utilities began funding solar projects at city facilities in 2002. It has offered residential rebates since July 2003 and commercial rebates since January 2008. In that time, more than $14 million has been provided toward the development of solar generation in the city.
"This is another important milestone clearly indicating that Riverside is a model solar city," said Riverside Mayor Ronald O. Loveridge in a news release. "Reaching this target confirms that our residents and business owners in Riverside are committed to their roles as stewards of the community and the environment."