Renewable energy

1. The process of using electricity to split water into hydrogen and oxygen gas
5. Heat energy extracted from Earth's internal molten rock and radioactive decay
10. Designing a building's orientation, windows, and thermal mass to collect solar heat without mechanical devices
11. A device that converts the kinetic energy of moving air into mechanical or electrical power
13. An electrochemical device that combines hydrogen with oxygen to produce electricity, with water and heat as byproducts
15. A semiconductor device that converts sunlight directly into DC electricity
16. A group of many wind turbines connected to the same electrical grid
17. A system that transfers heat between a building and the stable temperature of the ground

2. Energy derived from the gravitational pull of the moon on Earth's oceans
3. A solar technology that uses pumps or fans to circulate heat-absorbing fluid
4. A simple, glazed box containing dark absorber plates used to heat water or air for residential use
6. A renewable energy technology that exploits the temperature difference between warm surface seawater and cold deep seawater
7. A fuel made from living or recently living organisms, such as ethanol or biodiesel
8. A technology that uses mirrors or lenses to focus sunlight onto a receiver to generate high-temperature heat for electricity
9. Energy derived from organic plant and animal materials, including wood, crops, and manure
12. Electricity generated by burning organic matter such as wood chips, crop waste, or landfill gas
14. Energy generated from moving water, typically using dams or run-of-river systems