|Also called: renewable energy a form of energy derived from a natural source, such as the sun, wind, tides, or waves|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|a gadget; dingus; thingumbob.|
usable energy derived from replenishable sources such as the Sun (solar energy), wind (wind power), rivers (hydroelectric power), hot springs (geothermal energy), tides (tidal power), and biomass (biofuels).
Learn more about alternative energy with a free trial on Britannica.com.