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 Efficiency

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

Flex-Fuel Boilers

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

Biomass

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

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

Cellulosic Ethanol

Ethanol made from plant material

Geothermal Energy

Energy drawn from the internal heat of the earth, either through geysers, fumaroles, hot springs, 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