Green power marketing is catching on in California. Working Assets, which runs various progressive businesses including a long-distance phone service company, is teaming up with Green Mountain Energy Resources to sign up residential customers. Green Mountain is the only national energy provider to target the home market in California since the state's electricity market was deregulated on April 1. Working Assets hopes to provide one-fifth of Green Mountain's customers and in return the electricity provider will donate 1% of its sign-up revenue to environmental groups. One-fourth of Working Assets 300,000 phone customers are in California. In April Toyota Motor Sales Corp also announced it would buy 100% renewable energy (Windpower Monthly, June 1998) and now yet another company, "cleen n green" is targeting the state's residential market with renewables power, including wind. The firm is owned by Preferred Energy Services, which helps customers such as MCI Corp and the Silicon Valley cities of San Jose and Santa Clara cut their electricity bills. "There's a niche of people we feel are willing to pay a slight premium over the [current] utility cost to get renewable power," says president Rick Kohl, who used to work for the major utility PG&E.