2A. Alternative Energy Energy sources that are still in development. They require further research to see if they are cost-effective and non-polluting.
3B. Tidal PowerTides – movement of water in the oceans and seas caused by the gravitational attraction between the sun, Earth, and moon.
4B. Tidal PowerTides change twice each day, and this energy can be used to turn turbines.Similar to a hydroelectric dam
5B. Tidal PowerUsed nearly a thousand years ago to power mills in France and BritainCurrently used in France, Russia, and Canada to generate electricity.
6B. Tidal Power Disadvantages: Expensive to build and maintain Few suitable locations available
7C. Ocean Thermal Energy Conversion (OTEC) Natural temperature differences occur in the tropics, with warm surface waters and cold deep waters.Warm surface water is used to create steamCooled off by cold deep waters
8C. Ocean Thermal Energy Conversion (OTEC) The steam turns a turbine to generate electricity.Currently being experimented with in Japan.
9C. Ocean Thermal Energy Conversion (OTEC) Disadvantages:Not cost-effectiveThe power needed to pump cold water up from the deep ocean used one-third of the electricity the plant producesPossible environmental consequences
10D. Hydrogen The most abundant element in the universe When burned, it forms water vapor.Possible fuel cells used in cars
11D. Hydrogen Disadvantages: Water vapor is a major greenhouse gas Requires much energy to produce
12E. Energy Efficiency (EE) The percentage of energy put into a system that does useful workEE (%) = energy out x 100energy in
13E. Energy Efficiency (EE) Most energy that is lost is in the form of heat.Most inefficient machines: internal combustion enginesHybrid cars are much more efficient
14F. Energy Conservation Saving energy Everyone’s responsibility By turning off lights, unplugging appliances, and carpooling, bicycling, or walking, you can save a lot of energy!