The renewable energy and energy efficiency industry, in the tradition of electronics, biotechnology, and other technology-driven investment waves, is the newest industry to attract the attention of investors and economic developers worldwide. The industry is broadly defined by technologies and services that reduce or eliminate the environmental impact of primary energy production, energy consumption and electricity generation.

The industry can be divided into two broad subsectors, each focused on complementary but distinct areas: renewable energy and energy efficiency.

The renewable energy industry is focused on the production of energy forms that are environmentally sustainable and that reduce the environmental impacts of energy production. Companies in this subsector focus on several key areas of the energy infrastructure, including manufacturing of clean energy production equipment like solar panels, wind turbines and components, and biofuels, providing cost-effective, non-polluting machinery for electricity production or cleaner transportation fuels. While this emerging industry has traditionally been analyzed in terms of energy production technologies, energy efficiency's importance to the overall industry has risen dramatically.

The energy efficiency industry is driven by advances in green building and energy and water conservation technologies, battery technologies and energy storage, smart grid technologies, superconducting electrical transmission lines, and a wide variety of electronic, mechanical, and industrial processes and services.