In energy efficiency and conservation: all types of energy available commercially including natural gas (liquid natural gas and liquid oil gas), all heating and cooling fuels (including district heating and district cooling), coal, transport fuels, and renewable energy sources. [Section 4(f), Energy Efficiency and Conservation Act of 2019; Rule II(h), Department Circular No. DC 2019-11-0014, Implementing Rules and Regulations of Republic Act No. 11285 (Energy Efficiency and Conservation Act)]
In energy generation, solid waste: the power derived from the utilization of physical or chemical resources [Section 4(i), NSWMC Resolution No. 669, Series of 2016, Guidelines Governing the Establishment and Operation of Waste-to-Energy Technologies for Municipal Solid Waste]