California Code, Public Utilities Code - PUC § 224

“Heat corporation” includes every corporation or person owning, controlling, operating, or managing any heating plant for compensation within this state, except where heat is generated on or distributed by the producer through private property alone solely for his own use or the use of his tenants and not for sale to others.

“Heat corporation” shall not include a corporation or person employing landfill gas technology for the production or generation of heat for its own use or the use of its tenants or for sale to a heat corporation or state or local public agency.