Bioenergy refers to the energy that is derived from organic matter, such as plants, and animal waste. When it comes to synonyms for bioenergy, there are a few options that could be used. One alternative is biopower, which refers to the use of biomass to generate electricity. Another synonym is biomethane, which refers to a purified form of biogas that can be used as a fuel source. Biofuel is another popular synonym for bioenergy, which refers to the liquid fuel that is produced from biomass, such as ethanol and biodiesel. Finally, there is also the term biothermal, which refers to the heating and cooling energy that can be obtained from organic matter.