When residents of Santa Rosa flip a wall switch, they can take a little credit for the lights that come on. In this California city, yesterday’s toilet flush is today’s electricity.
Santa Rosa and Calpine Corporation, an wenergy company, are partners in the world’s largest geothermal wastewater-to-power project. They are using urban effluent to generate clean energy, improving life not only for humans but also for fish. For the city, the partnership has eliminated fines it was paying for dumping wastewater into the Russian River and the $400-million expense of building new wastewater storage facilities. For Calpine, the arrangement has revived geothermal steam fields that were declining from overuse.