Renewable Energy Alternatives
Biomass
Biofuels - Liquid fuels from biomass sources
Ethanol - The fermentation of starches or sugars (aka Alcohol).
Biodiesel - Produced from vegetable oil, such as soybean oil.
Biopower - Electricity that is generated by the combustion of biomass
Benefits and Costs of Biomass Energy: Benefits - the carbon produced by the combustion of biomass is the same amount that was removed from the atmosphere by photosynthesis. Costs - Biofuel crops take up land that might be used for growing food or left in its natural condition.
Geothermal
Ground Source Heat Pumps - A ground source heat pump takes advantage of the fact that the temperature of soil a few feet underground stays about the same all year, even though the air temperature changes with the seasons.
Generating Electricity - Geothermal energy can be turned into energy. Steam turns the blades of a turbine which makes a generator produce electricity.
Harnessing Geothermal Energy - The two ways of harnessing energy are deep drilling of wells by man, or geysers.
Using Heat Directly - Hot groundwater can be used directly for heating homes, offices, and greenhouses. Hot water us piped from its source into buildings. Heating groundwater is practical only where geothermal energy sources are nearby.
Benefits and Costs of Geothermal Energy: Benefits - Geothermal power causes far less air pollution than fossil fuel combustion. Costs - Geothermal sources are not always truly sustainable.
Hydropower
Using The Natural Flow Of A River - Water may be diverted through a pipe which carries the water to the turbines. Which does not disturb natural habitats as much.
Using Water Stored Behind Dams - Hydroelectric dams uses moving water to generate electricity. The river water passes through the dam, the water turns the blades of the turbines, which produce electricity.
Benefits and Costs of Hydropower: Benefits - Hydropower is renewable. Costs - Dams interrupt the natural flow of water, they drastically change ecosystems.
Energy From the Ocean - A daily cycle of tidal motion used to create electricity
Tidal Energy - Tidal energy is the use of movement of tidal water to generate electricity
Best Locations - Long, narrow bays
Benefits and Costs: Benefits- Hydropower is renewable, and there is no air pollution. Costs- Dams alter ecosystems, and dams can trap soil.
Thermal Energy From the Ocean- Warm ocean water is generating vapors that spin turbines.
Solar and Wind
Harnessing Solar Energy for Heat
Active Solar Heating- Uses technology to capture, store and distribute the suns energy. Such as solar pannels
Passive Solar Heating- A building designed to capture, store and distribute the suns energy.
Harnessing Solar Energy to Create Electricity
Photovoltaic Cells (Solar Panels) - Converts solar energy directly into electricity.
Concentrating Solar Power - Uses mirrors to focus the sun's rays onto a vessel that contains water.
Hydrogen
Hydrogen As A Fuel Source - H2 can be combusted and used as a heat source. H2 can be created by breaking down water or methane.
Benefits and Costs of Hydrogen As A Fuel Source: Benefits- Hydrogen can be stored and transported and water and heat are the only byproducts. Costs- Hydrolysis is expensive and h2 must be compressed if used to be vehicle fuel.
Fuel Cells- H2 and O2 react to water, producing electricity in the fuel cell's electrodes