Winds are created by the unequal heating of the earth's
surface by the sun. When considred on a global basis winds contain
vast quantities of potentially useful energy. According to the U.S.
Department of Energy, the world's winds could potentially supply as
much as 3,900 quadrillion BTUs of energy each year, which is more
than ten times the total world energy demand.
A wind energy system is any mechanism that transforms kinetic
energy into useful mechanical or electrical energy. Electrical
wind systems, commonly called wind turbine generators (WTGs) are
used to generate electric power. WTGs are similiar to hydro turbines,
execpt they are driven by moving air rather than water. Today, there
are approximately 25,000 wind turbines generating 2,600 megawatts
and producing five billion kilowatts-hours of electricty a year.
Wind energy is very clean. Because it produces energy without the
emission ot air pollutants or greenhouse gasses.
The most economical application of wind electric turbines is in
groups of large machines with rotor diameter 30 m on up. Which are
called "windfarms." Today a 50-megawatt
windfarm can be completed in 18 months for five cents/kWh. In a typical
windfarm, a converter changes the electricity produced by the turbines
into power with a voltage and quality compatible with local transmission
grid.
With the increasing dependence on fossil fuels in addition to ther
well known negative environmental impacts. Wind energy is becoming and
increasingly important factor.
Solar power is another alternate energy source theat has many applications. It is used in homes as a source of heat as well as energy. In Europe there are several completey solar powered homes built whigh the public can tour. They have data taken on them telling the power generated and conjsummed per year. Showing that a solar house is a feasible way of living. SOLAR HOUSE
The sun's rays can also power automobiles, sending them up to 75mph. There are many schools and organizations who sponser contests to see who can design and build the fastest solar powered vehicles. Solar energy cells are expensive and this is one of the contributing factors in its small amount of usage. Only 100,00 families are using solar-powered lighting. This is out of the over 5 Billion people in the world. The average price per kilowatt hour of electricity in the United states is 7 cents oer KWh. But is can go up to 30 cents per KWh during peak periods in many parts of the nation. Many developing countries obtain energy from batteries, ant the cost of several dollars per KWh. Obviously, solar power is going to be more conpetitive than this in the long run. Nuclear Engineers beware!
Alternate energy
Solar Cells
Geothermal
American Solar Energy Society