Biomass Energy

For those who don't know what Biomass is, it is energy that is generated using organic minerals from the earth that can be either renewable or nonrenewable. Wood was once our main fuel. We burned it to heat our homes and cook our food. Wood still provides a small percentage of the energy we use, but its importance as an energy source is growing thin. Wastes such as animal manure, wood chips, seaweed, corn stalks, and even trash can even be broken down into usable energy. "Bioconversion" uses plant and animal wastes to produce "Biofuel" such as methanol, natural gas, and oil.

Advantages: It makes sense to use waste materials where we can. The fuel tends to be cheap, and there is less demand on the fossil fuels. 

Disadvantages: Collecting or growing the fuel in sufficient quantities can be difficult. We burn the biofuel, so it makes greenhouse gases just like fossil fuels do, and some waste materials are not available all year round. 

http://www.darvill.clara.net/altenerg/biomass.htm#intro

Hydro Power

Hydro energy is simply energy that is taken from water and converted to electricity. Hydro energy can be obtained by using many methods of capture. The most common method of using energy from water is a hydroelectric dam, where water coming down through an area causes turbines to rotate and the energy is captured to run a generator. Power can also be generated from the energy of tidal forces or wave power, which uses the energy created by waves.

One downside to using hydro energy is that it can sometimes change the natural flow of the water which can make it possible to harm plants and animals in the water. It can also damage areas and wildlife, as when creating a hydro electric dam, areas must be flooded. 

Other reasons that many want to use hydro energy is that it is cheaper than using other methods to convert energy to electricity. It is also reliable and can be used almost immediately when turned on to meet the demand for electricity. Therefore, you must weigh the pros and cons before deciding to use hydro energy to supply their demand for electricity.

Solar Energy

Solar energy has been used by humans for thousands of years.  For example, ancient cultures used energy from the sun to keep warm by starting fires with it.  They also kept their homes warm through passive solar energy designs. But isn't solar energy expensive to maintain? In fact, An economic breakthrough occurred in the 1970's when Dr. Elliot Berman was able to design a less expensive solar cell bringing the price down from $100 per watt to $20 per watt.  This huge cost savings opened up a large number of applications that were not considered before because of high costs.  These applications included railroads, lighthouses, off-shore oil rigs, buoys, and remote homes.  For some countries and many applications, solar energy is now considered a primary energy source, not an alternative.

Solar energy is one of the only sources known to man to be able to last all day and all night. Because although the sun only stays out for a portion of the day, the panels absorb the sun's energy and stores it so that it may used when the panel itself isn't. Researchers have developed cells with more than 20% efficiencies.  20% efficient means that out of the total energy that hits the surface of a solar cell, about 20% is converted into usable electricity.

http://www.youtube.com/watch?v=EsiFzFDI54Q
http://www.makeitsolar.com/solar-energy-information/01-solar-history.htm