NRG Energy Inc., the worst-performing member of the S&P 500 Utilities Index this year, said it will form a renewable energy unit and sell wind assets to its existing yield-focused business.

The biggest U.S. independent power producer will place its home solar, electric car charging unit and large-scale solar development business in a so-called GreenCo, the Princeton, New Jersey-based company last week in a slide presentation for investors posted on its website. The GreenCo will be created on Jan. 1, 2016.