Al Gore recently gave a speech discussing the environment and telling us what we needed to do to save energy. There are eight alternative energies that we could use.
General Renewable Energy Resources: Which is energy generated from natural resources—such as sunlight, wind, rain, tides and geothermal heat—which are renewable (naturally replenished)General, Solar Thermal,
Solar Electric (Photovoltaic),Wind,Hydroelectric,Biomass,Alternative Fuels,
Ocean Thermal Energy Conversion (OTEC),Wave Energy,Tidal Energy, and Geothermal Energy.
Solar Energy Resources:Solar Cells are really called "photovoltaic" or "photoelectric" cells) that convert light directly into electricity. In a sunny climate, I can get enough power to run a 100W light bulb from just one square meter of solar panel. This was originally developed in order to provide electricity for satellites, now many of us own calculators powered by solar cells. Solar water heating, When the heat from the sun is used to heat water up in glass panels on my roof, this means you don't need to use so much gas or electricity to heat my water at my home.
Solar Furnaces, Use a huge array of mirrors to concentrate the Sun's energy into a small space and produce very high temperatures.They have one at Odellio, in France, used for scientific experiments. It can achieve temperatures up to 33,000 degrees Celsius.
Wind energy resources,
Wind is simple air in motion. It is caused by the uneven heating of the earth’s surface which is created by the sun. Since the earth’s surface is made of very different types of land and water, it absorbs the sun’s heat at different rates.
During the day, the air above the land heats up quicker than the air over water. The warm air over the land expands and rises, the heavier and cooler air rushes in to take its place, creating winds. At night, the winds are reversed because the air cools more rapidly over land than over water. In the same way, the large atmospheric winds that circle the earth are created because the land near the earth's equator is heated more by the sun than the land near the North and South Pole. Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines
Nuclear energy resources: Nuclear power is generated using Uranium, which is a metal mined in many parts of the world. The first large-scale nuclear power station opened at Calder Hall in Cumbria, England, in the year 1956. Some military ships and submarines have nuclear power plants for engines. Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you'd get from burning fossil fuels.
Hydroelectric Energy Resources:
The first house in the world to be lit by hydroelectricity was Crag side House, in Northumberland, England, in 1878. There are many hydro-electric power stations, providing around 20% of the world's electricity. The name comes from "hydro", the Greek word for water.How does it work?
A dam is built to trap water, usually in a valley where there is an existing lake. Water is allowed to flow through tunnels in the dam, to turn turbines and thus drive generators.
The dam is much thicker at the bottom than at the top, because the pressure of the water increases with depth. Hydro-electric power stations can produce a lot of power very cheaply.
When it was first built, the huge "Hoover Dam", on the Colorado river, supplied much of the electricity for the city of Las Vegas; however now Las Vegas has grown so much, the city gets most of its energy from other sources. There's a good explanation of how hydro power works at www.fwee.org. There are many suitable sites around the world, hydro-electric dams are very expensive to build. However, once the station is built, the water comes free of charge, and there is no waste or pollution. Although the dams are very expensive, after the dam is built, you'll be saving lots and lots of money.
Biomass Energy Resources:
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. Sugar cane is grown in some areas, and can be fermented to make alcohol, which can be burned to generate power.
Alternatively, the cane can be crushed and the pulp (called "bagasse") can be burned, to make steam to drive turbines. Other solid wastes, can be burned to provide heat, or used to make steam for a power station.
"Bio conversion" uses plant and animal wastes to produce fuels such as methanol, natural gas, and oil.
We can use rubbish, animal manure, wood chips, seaweed, corn stalks and other wastes.
How does it works?
The fuel is burned, which heats water into steam, which turns turbines, which in turn drive generators, just like in a fossil-fuel power station.
Sugar cane
Sugar cane is harvested and taken to a mill, where it is crushed to extract the juice. The juice is used to make sugar, whilst the left-over pulp, called "bagasse" can be burned in a power station.
The station usually provides power for the sugar mill, as well as selling electricity to the surrounding area.
Advantages
It makes sense to use waste materials where we can.
The fuel tends to be cheap.
Less demand on the Earth's resources.It's all about saving energy and money and as a nation we need to figure out the best way to do that.
Geothermal energy
The centre of the Earth is around 6000 degrees Celsius - hot enough to melt rock. Even a few kilometres down, the temperature can be over 250 degrees Celsius.
In general, the temperature rises one degree Celsius for every 36 metres you go down.
In volcanic areas, molten rock can be very close to the surface.
Geothermal energy has been used for thousands of years in some countries for cooking and heating.
The name "geothermal" comes from two Greek words: "Geo" means "Earth" and "thermal" means "heat".
How it works
Hot rocks underground heat water to produce steam. We drill holes down to the hot region, steam comes up, is purified and used to drive turbines, which drive electric generators.
There may be natural "groundwater" in the hot rocks anyway, or we may need to drill more holes and pump water down to them.
The first geothermal power station was built at Landrello, in Italy, and the second was at Wairekei in New Zealand. Others are in Iceland, Japan, the Philippines and the United States.
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