Pacific Gas & Electric says its residential and business customers can voluntarily join a ClimateSmart program that will calculate a customer’s energy use and set a monthly charge for PG&E projects to fight global warming by offsetting the customer’s emissions, Reuters reports.

PG&E will put the money into two projects managing forest preservation and converting methane from livestock manure into biogas energy. The utility has put out an RFP for offset programs, which must be in California and approved by the California Climate Action Registry.

PG&E said it expects the program to receive about $20 million in its first three years.

The California Public Utilities Commission approved the program in December.