Balance of plant - Optimization of a plant's equipment aimed at maximizing energy, water efficiency, as well as minimizing pollution and waste.

Basic industries - Collection of enterprises that produce the refined basic materials necessary for manufacturing consumer goods and that use raw materials from extractive industry.

Batteries - Combination of electrochemical cells that store electricity.

Battery electric vehicles (BEV) - Vehicles that completely rely on electricity storage batteries as a power source and are driven by electric motors.

Battery storage - Electrochemical cells that can be used to store energy. They are able to be charged using electricity and then discharged to produce electricity.

Biochemicals - Chemicals that are naturally existing and occur without artificial aid.

Biodiesel - Non-petroleum-based diesel fuel that utilizes either vegetable oil or animal fat.

Bioethanol - Ethyl alcohol (an alternative to gasoline) is produced from certain agricultural crops through a microbial sugar fermentation process.

Biofuels - Solid, liquid or gaseous fuels derived from biological materials (e.g. sugar cane or feedstock). Biodiesel and bioethanol are the most common types of biofuels used in automobiles.

Biogas - Type of biofuel that is produced by the breakdown of organic matter via fermentation, producing mainly carbon dioxide and methane, or the gasification of wood matter, producing nitrogen and hydrogen.

Bioheat - Fuel comprised of a blend of heating oil and biofuel used mainly for home heating applications.

Biological flocculation - Process where pollutants in water are concentrated together in the form of flakes, which are used in the purification of drinking water and treatment of sewage.

Biological wastewater treatments - Treatment methods that usually seek to reduce the organic and nutrient content (notably nitrogen and phosphorus) of wastewater.

Biomass - Renewable energy source comprised of living or recently dead biological material (plant or animal matter) that can be converted into fuel.

Biomass co-firing - Process that generates power plant electricity by simultaneously burning biomass with coal.

Biomass combustion - Burning of biomass to generate power plant electricity.

Biosphere - Term used to describe the entire global ecological system and the relationship of its inhabitants.

Building energy intensity- Measurement of a building’s energy efficiency calculated as units of energy per square meter.

Building integrated heat and power - Combination of heating and power generation solutions that could be integrated into a building. Some of which include solar photovoltaic cells, wind turbines and solar water heaters.

Building integrated photovoltaics (BIPV) - Application of solar photovoltaic materials, whether crystalline or thin-film, into actual building structures. This normally replaces conventional building materials in parts of the building envelope such as the roof, skylights or facades.

Build-operate-transfer (BOT) - Arrangement wherein the government awards a franchise license to a private sector company (including foreign companies) for a certain period of time. This in turn permits the construction and operation of a specific public infrastructure project, which is eventually transferred to the government free of charge when the concession period expires.

Bus rapid transit (BRT) - An efficient bus system resulting from improvements in infrastructure, vehicles, and schedules.