Alternate+Energy

 What are the Alternatives? Alternative energy resources are almost always renewable. They are eco- friendly and do not present any dangerous consequences for our future.


 * [[image:http://tonto.eia.doe.gov/energy_in_brief/images/charts/Renew_consumption.png width="450" height="269" caption="Pie chart showing: Total=101.605 quadrillion BTU; Petroleum 40%; Natural Gas 23%; Coal 22%; Nuclear Energy 8%; Renewable Energy 7%. Total Renewable Energy=6.830 quadrillion BTU; Biomass 53%; Hydroelectric 36%; Geothermal 5%; Wind 5%; Solar 1%. Note: Sum of components may not equal 100 percent due to independent rounding. Source: EIA, Renewable Energy Consumption and Electricity Preliminary 2007 Statistics (May 2008)."]] ||

Biomass ** Biomass is organic material made from plants and animals. Biomass is a renewable energy source because trees and crops are constantly being grown, and waste will always exist. Some examples of biomass fuels are wood, crops, manure, and even garbage. Energy is most commonly retrieved from biomass by burning it. Though it produces some smoke pollution, it accounts for much less than fossil fuels. Biomass fuels provide about 3 percent of the energy used in the United States. People in the USA are trying to develop ways to burn more biomass and less fossil fuels. Using biomass for energy can cut back on waste and support agricultural products grown in the United States. Wood- The most common form of biomass. For years and years, wood was the only source of energy for used by the world. Since the mid 1800's the U.S and other developed countries have lowered their use of wood. Biomass continues to be a major source of energy in undeveloped countries. In the United States wood and waste (bark, sawdust, wood chips, and wood scrap) provide only about 2 percent of the energy we use today. Nearly 84% of the wood and wood waste fuel used in the United States is consumed by the industry, electric power producers, and commercial businesses. The rest, mainly wood, is used in homes for heating and cooking in fireplaces and furnaces. Many manufacturing plants in the wood and paper products industry use wood waste to produce their own steam and electricity. This saves these companies money because they don't have to dispose of their waste products and they don't have to buy as much electricity.

MSW- Municipal Solid Waste is garbage that comes from plants and animals. (Leaves, tree branches, food scrappings) These wastes can be converted to energy in two different ways: in waste-to-energy plants, or by intaking biogas. Waste-to-Energy plants simply burn garbage to create steam to heat buildings or to generate electricity. The other way to obtain energy from MSW in to capture biogas. Biogas is the methane that is released by organic materials in landfills. Some tanks called digesters are used by some farmers to take methane gas and use it as a fuel source. Ethanol and Biodiesel- Ethanol is formed from the sugars found in many grains such as corn, sorghum, wheat, potato skins, rice, sugar cane, sugar beets, and even yard clippings. Because it is extremly expensive, scientists are looking for a way to make it from trees and more common plants. Biodiesels are made from vegetable oils and grease, and fats. It is a very fast growing alternative energy source because it is biodegradable, renewable, and easy to find. Burning biomass is more environmentally friendly than fossil fuels in many ways. First of all, it produces much less carbon dixide. Also, its use lowers the emissions of carbon monoxide, sulfer, and methane, which are other harful greenhouse gases. Other economic pros include saving money for handling most wastes, and the recession of landfills.

**Solar** The sun has the potential to be a great energy source. The sun, an average star, is a fusion reactor that has existed over 4 billion years. It provides enough energy in one minute to supply the world's energy needs for one year. In one day, it provides more energy than our current population would consume in 27 years. In fact, "The amount of solar radiation striking the earth over a three-day period is equivalent to the energy stored in all fossil energy sources." Solar energy can be converted to electricity in two ways: Photovoltaic PV cells change sunlight directly into electricity. Solar Power Plants - indirectly generate electricity when the heat from solar thermal collectors is used to heat a fluid which produces steam that is used to power generator. The major disadvantages of solar energy are:


 * The amount of sunlight that arrives at the earth's surface is not constant. It depends on location, time of day, time of year, and weather conditions.
 * Because the sun doesn't deliver that much energy to any one place at any one time, a large surface area is required to collect the energy at a useful rate.

Hydroelectric Power
To produce of energy from water, you must build a dam on a large river that has a large drop in elevation. The dam stores lots of water behind it in the reservoir. Near the bottom of the dam wall there is the water intake. Gravity causes it to fall through the penstock inside the dam. At the end of the penstock there is a turbine propeller, which is turned by the moving water. The shaft from the turbine goes up into the generator, which produces the power. Power lines are connected to the generator that carry electricity to your home and mine. The water continues past the propeller through the tailrace into the river past the dam. By the way, it is not a good idea to be playing in the water right below a dam when water is released


 * Hydropower is the most important and widely-used renewable source of energy.
 * Hydropower represents 19% of total electricity production.
 * Canada is the largest producer of hydroelectricity, followed by the United States and Brazil.

Advantages to hydroelectric power:

It's renewable
 * Fuel is not burned so there is minimal pollution
 * Water to run the power plant is provided free by nature
 * Hydropower plays a major role in reducing greenhouse gas emissions
 * Relatively low operations and maintenance costs
 * The technology is reliable and proven over time

Hydroelectric power also has some disadvantages:


 * High investment costs
 * Hydrology dependent (precipitation)
 * In some cases, inundation of land and wildlife habitat
 * In some cases, loss or modification of fish habitat
 * Fish entrainment or passage restriction
 * In some cases, changes in reservoir and stream water quality
 * In some cases, displacement of local populations

Nuclear
Uranium is a common element on Earth. It's been around since the planet formed. Uranium-238 (U-238) has an extremely long half-life (the time it takes for half its atoms to decay) of 4.5 billion years. Therefore, it's still present in fairly large quantities. U-238 makes up 99 percent of the uranium on Earth, while uranium-235 (U-235) makes up about 0.7 percent of the remaining uranium found naturally. Uranium-234 is even rarer, formed by the decay of U-238. U-238 goes through many stages of decay in its life span, eventually forming a stable isotope of lead, so U-234 is just one link in that chain. Uranium-235 has an interesting property that makes it handy for the production of both nuclear power and nuclear bombs. U-235 decays naturally, just as U-238 does, by alpha radiation: It throws off an alpha particle, or two neutrons and two protons bound together. U-235 also undergoes spontaneous fission a small percentage of the time. However, U-235 is one of the few materials that can undergo induced fission. If a free neutron runs into a U-235 nucleus, the nucleus will absorb the neutron, become unstable and split immediately.

There are many advocates for nuclear because it produces very few quantities of CO2. Historically, mining and purifying uranium hasn't been a very clean process. Even transporting nuclear fuel to and from plants poses a contamination risk. And once the fuel is spent, you can't just throw it in the city dump. It's still radioactive and potentially deadly. On average, a nuclear power plant annually generates 20 metric tons of used nuclear fuel, classified as **high-level radioactive waste**. When you take into account every nuclear plant on Earth, the combined total climbs to roughly 2,000 metric tons yearly. All of this waste emits radiation and heat, meaning that it will eventually corrode any container and can prove lethal to nearby life forms. As if this weren't bad enough, nuclear power plants produce a great deal of **low-level radioactive waste** in the form of radiated parts and equipment. Eventually spent nuclear fuel will decay to safe radioactive levels, but it takes tens of thousands of years. Even low-level radioactive waste requires centuries to reach acceptable levels. Currently, the nuclear industry lets waste cool for years before mixing it with glass and storing it in massive cooled, concrete structures. In the future, much of this waste may be transported deep underground. In the meantime, however, this waste has to be maintained, monitored and guarded to prevent the materials from falling into the wrong hands. All of these services and added materials cost money-- on top of the high costs required to build a plant. Nuclear waste can pose a problem, and it's the result of properly functioning nuclear power plants. When something goes wrong, the situation can turn catastrophic. The Chernobyl disaster is a good recent example. In 1986, the Ukrainian nuclear reactor exploded, spewing 50 tons of radioactive material into the surrounding area, contaminating millions of acres of forest. The disaster forced the evacuation of at least 30,000 people, and eventually caused thousands to die from cancer and other illnesses