As an effect, the number of cogeneration plants, which produce electric power and steam, increased. These plants are encouraged by the law, on the basis that they harness thermal energy (in the form of usable steam) that would be otherwise wasted if electricity alone was produced. PURPA also became the basic legislation that enabled renewable energy providers to gain a toehold in the market, particularly in California, where state authorities were more aggressive in their interpretation of the statute. The portion of the act dealing with cogeneration and small power production appears in US code in Title 16 – Conservation, Chapter 12 – Federal Regulation and Development of Power, Subchapter II – Regulation of Electric Utility Companies Engaged in Interstate Commerce, Sec 824a-3 – Cogeneration and Small Power Production.