Alternative energy

Alternative energy is derived from sources other than traditional fossil fuels, though these sources need not be renewable or green to be alternative. Some alternative fuels recognized by the Energy Policy Act of 1992 are biodiesel, electricity, ethanol, hydrogen, methanol, natural gas and propane. The problem with several of these alternative fuels is that they still use materials that create harmful emissions and are environmentally costly to produce and transport. This makes it very important to support alternative energy sources and technologies that are also renewable and green.

Renewable energy sources effectively utilize natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. Renewable energy technologies range from solar power, wind power, and hydroelectricity to biomass and bio-fuels for transportation.

While renewable energy sources like wind and solar power are becoming more familiar as the discussion around alternative energy steadily increases, the facts about sources like biomass have remained somewhat mysterious. Biomass refers to living and recently dead biological material that can be used as fuel or for industrial production. Most commonly, biomass refers to plant matter grown for use as bio-fuel, but it also includes plant or animal matter used for production of fibers, chemicals or heat. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum. Biomass can be produced by low-tech processes like composting, or very high-tech processes like Pyrolysis (the heating of organic wastes in the absence of air to produce gas and char.

Upon death or combustion, a plant's carbon- atmospheric carbon initially converted into biological matter by photosynthesis- is released back into the atmosphere as carbon dioxide (CO2). When biomass is used as a direct replacement for fossil fuels, it still puts the same amount of CO2 into the atmosphere. However, when biomass is used for energy production it is widely considered carbon neutral, or a net reducer of greenhouse gasses because of the offset of methane that would have otherwise entered the atmosphere.

About 13% of primary energy comes from renewable sources, with most of this coming from traditional biomass like wood burning. Hydropower is the next largest source, providing 2-3%, and modern technologies like geothermal, wind, solar and marine energies together produce less than 1% of total world energy demand. The technical potential for their use is large, exceeding all other readily available sources.

Active Solar - Active solar is an application, that uses electrical or mechanical equipment (typically pumps and/or fans) to assist in the collection and storage of solar energy for the purpose of heating, cooling (buildings, liquids, or gases), or making electricity.

Alternative energy - Alternative energy substitutes for traditional, often non-renewable sources of energy such as oil and coal. Alternative energy includes, but is not limited to solar, wind, hydro and geothermal power, as well as mixtures of alcohol-based fuels with methanol, ethanol, compressed natural gas and others.

Cogeneration - Cogeneration is a process in which power is produced by a gas-fired engine and generator set. Heat produced as part of this process is used as heating and/or cooling media. A cogeneration plant is often referred to as a combined heat and power plant.

Daylighting - Daylighting is the use of natural light to supplement or replace artificial lighting.

Fuel Cell - A fuel cell is an electrochemical device in which hydrogen is combined with oxygen to produce electricity with heat and water vapor as by products. Natural gas is often used as the source of hydrogen with air as the source of oxygen. Since electricity is produced by a chemical reaction and not by combustion, fuel cells are considered to be green power producers. Fuel cell technology is quite old, dating back to the early days of the space program. Commercial use of fuel cells has been sporadic, however, the use of fuel cells in automobiles and buildings is expected to increase in the next decade.

Geothermal Energy - Geothermal energy is a form of energy produced through drilling and harvesting heat trapped deep within the earth. Extraction methods include bringing water that has been superheated below ground to the surface, or pumping water deep into the earth to become heated and then pumped out again.

Light Shelf - A light shelf is a horizontal device positioned (usually above eye level) to conserve energy by reflecting daylight onto the ceiling and beyond. The light shelf may project into the room, beyond the exterior wall plane, or both. The upper surface of the shelf is highly reflective, i.e. having 80 percent or greater reflectance. Light shelves are also effective shading devices for windows located below them.

Passive solar - Passive solar is the use of sunlight for energy without the need for mechanical devices. Capturing sunlight in this way can be used to create heat for stored or immediate use, and to create air movement for ventilation.

Photovoltaic Cell - A photovoltaic cell device that converts sunlight directly into electricity. Photovoltaic (PV) cells are silicon-based semiconductors and are often referred to as solar cells. PV cells were developed in the mid-1950's and have become cost effective where it is difficult to extend conventional power lines. PV cells are often used for remote motorist call aid boxes, irrigation systems and navigational lights.

Solar Energy - Solar energy is obtained by capturing the suns rays and is utilized for heating and powering. The three most common methods of using solar energy are: Passive Solar, Active Solar, Solar Photovoltaic (PV) Systems.

Solar Insolation - Solar insolation is the amount of direct, diffuse and reflected sunlight reaching an area exposed to the sky. Solar insolation maps of your area can be used to help you size a solar electric (PV) system to meet your energy needs during the periods of the year with the shortest amount of sunshine for your location.

Wind Energy - The Sun heats the earth unevenly, creating thermal air pockets. In order to achieve equal temperatures around the earth these air pockets move about the earth as wind. The energy that travels in the wind can be captured through the use of wind turbines and converted to provide electricity.

Wind Turbine - A wind turbine is a device that converts the kinetic energy of the wind into mechanical energy that can be used to drive equipment such as pumps. The addition of a generator allows the wind's kinetic energy to be converted into electricity.