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Visible light is only one type of EM wave. We use different kinds of electromagnetic waves for many different purposes.

There have been studies that prove the many benefits of substituting fossil fuels (petroleum, etc) with biofuels such as biodiesel and ethanol. In its simplest sense, such biofuels are biodegradable which means they are derived from organic materials. They are naturally renewable. It can create numerous jobs since our own farmers can practically make them domestically. Consequently, our reliance on foreign sources of fossil fuels will be significantly reduced. Moreover, these biofuels emit nontoxic and cleaner emissions in comparison to traditional fuels. These alternative fuels also do not promote global warming, since the carbon they emit is taken back to the environment.

biofuel is far more simple and easy to use

Power density: Power from a solar array is limited by the size of the vehicle and area that can be exposed to sunlight. While energy can be accumulated in batteries to lower peak demand on the array and provide operation in sunless conditions, the battery adds weight and cost to the vehicle. The power limit can be mitigated by use of conventional electric cars supplied by solar (or other) power, recharging from the electrical grid.

biofuel

a gaseous, liquid, or solid substance of biological origin that is used as a fuel

By the time it reaches Earth's surface, the energy in sunlight has fallen to about 1,000 watts per square meter at noon on a cloudless day. Averaged over the entire surface of the planet, 24 hours per day for a year, each square meter collects the approximate energy equivalent of almost a barrel of oil each year, or 4.2 kilowatt-hours of energy every day. Deserts, with very dry air and little cloud cover, receive the most sun—more than six kilowatt-hours per day per square meter. Northern climates, such as Boston, get closer to 3.6 kilowatt-hours. Sunlight varies by season as well, with some areas receiving very little sunshine in the winter. Seattle in December, for example, gets only about 0.7 kilowatt-hours per day. It should also be noted that these figures represent the maximum available solar energy that can be captured and used, but solar collectors capture only a portion of this, depending on their efficiency. For example, a one square meter solar electric panel with an efficiency of 15 percent would produce about one kilowatt-hour of electricity per day in Arizona.

global potential is enormous: over 400 billion liters annually, well more than double the amount of diesel the US burns every year.

Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol.

How Does Wind Energy Work? The diagram below shows a simplified version how a wind turbine converts the kinetic energy in the wind to electrical energy around the country. If you can't see the diagram you will need to download flash to see it. The wind blows on the blades and makes them turn. The blades turns a shaft inside the nacelle (the box at the top of the turbine) The shaft goes into a gearbox which increases the rotation speed enough for... The generator, which uses magnetic fields to convert the rotational energy into electrical energy. These are similar to those found in normal power stations. The power output goes to a transformer, which converts the electricity coming out of the generator at around 700 Volts (V) to the right voltage for distribution system, typically 33,000 V. The national grid transmits the power around the country.

One of the main disadvantages is the initial cost of the equipment used to harness the suns energy

A solar energy installation requires a large area for the system to be efficient in providing a source of electricity

pollution can degrade the efficiency of photovoltaic cells. Clouds also provide the same effect, as they can reduce the energy of the suns rays

Price projections vary among fuel cell developers, but most are targeting costs below $1,500/kW

Maintenance costs of a fuel cell are expected to be comparable to that of a microturbine, ranging from $0.005-$0.010/kWh (based on an annual inspection visit to the unit).

At the current price, units are only used in high value, "niche" markets where reliability is premium, and in areas where electricity prices are very high and natural gas prices are low.