Env Science #3 Sustainable Energy

Light-Emitting Diodes (LEDs)- A semiconductor light source

Passive Houses- Highly insulated, virtually airtight buildings heated primarily by passive solar gain and by the energy released by people, electrical appliances, cooking, and other ordinary activities

Passive Heat Absorption- The use of natural materials or absorptive structures without moving parts to gather and hold heat; the simplest and oldest use of solar energy

Active Solar System- A mechanical system that uses moving parts or pumped fluids to collect, concentrate, distribute, or store solar energy

Concentrating Solar Power System- A facility that captures solar energy to generate steam, which turns a turbine to produce electricity 

Power Tower- A high temperature concentrating solar power system in which thousands of mirrors arranged in concentric rings around a tall central tower track the sun and focus light on a heat absorber to generate steam, which drives an electrical generator

Photovoltaic Cells- An energy-conversion device that captures solar energy and directly converts it to an electrical current

Feed-in Tariffs- Require utilities to buy surplus power from small producers at a fair price. These tariffs are generally essential to individual solar installations

Wind Turbines- Large windmills that produce electricity

Conversion Effciency- How much input energy is converted to useful work

Capacity Factor- How much of the theoretical maximum is produced over time

Low-Head hydropower- Small-scale hydro technology that can extract energy from small headwater dams; causes much less ecological damage

Biomass- The total mass or weight of all the living organisms in a given population or area

Flex-fuel Boilers- Boilers that can use a variety of different fuels; coal, oil, biomass, etc

Cogeneration- The simultaneous production of electricity and steam or hot water in the same plant

Methane- CH4; the simplest hydrocarbon and the main component of natural gas

Biofuels- Fuels such as ethanol, methanol, biodiesel, or vegetable oils from crops

Cellusloic Ethanol- Ethanol made from plant material

Geothermal Energy- Energy drawn from the internal heat of the earth, either through geysers, fumaroles, hotsprings, or other natural geothermal features, or through deep wells that pump heated groundwater

Fuel Cells- Mechanical devices that use hydrogen-containing fuels such as methane to produce an electric current. Fuel cells are clean,quiet, and highly efficient sources of electricity