Our natural resources are being used up. In the not-to-distant future, alternative energy sources will become a part of everyday life. Solar power, wind power, geothermal energy, tidal dams, and hydroelectric dams will become major contributors in fulfilling our energy requirements. In this activity, you will learn more about alternative energy sources.

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Alternative energy sources are all those things that do not consume fossil fuel. They are widely available and environmentally friendly. They cause little or almost no pollution. Alternative energy sources are renewable and are thought to be "free" energy sources. They all have lower carbon emissions compared to conventional energy sources. Let's take a look at some of these alternative energy sources below.

Solar Power

Solar energy is one the most available sources of energy for the future. The total energy we receive each year from the sun is about 35,000 times the total energy used by man.

At present, solar energy is used on a small scale in furnaces for homes and to heat swimming pools. Solar farms are new — converting sunlight to electricity to add energy to our power lines. Solar energy could be used to operate cars, power plants, and space ships!

Wind Power

Wind power is another alternative energy source that can be used without by-products that are harmful to nature. Similar to solar power, harnessing the wind is highly dependent upon weather and location. Wind power is a renewable source of energy. It does not cause any air pollution. Advancement in technologies has brought down the cost of setting up wind farms. For example, the wind farms of southern Alberta are producing electricity to add to the supply.

Geothermal Power

Geothermal energy is an alternative energy source, although it is not likely to replace more than a minor amount of the future's energy needs. Geothermal energy is obtained from the internal heat of the planet and can be used to generate steam to run steam turbines that generate electricity, which is a very useful form of energy. On a small scale, it can be used to heat individual homes.

The Earth has an internal core temperature of about 4,000 degrees Celsius at the centre. The mantle surrounds the outer core and is only about 70 km (45 miles) below the surface, depending on location. The temperature at the mantle-surface crust boundary is about 375 degrees Celsius.

So, how does this help us? If we drill only 4 km into the Earth, we can reach temperatures of 100 degrees Celsius, which is enough to boil water to run a steam-powered electric power plant. Such drilling is possible but not easy. Fortunately, easier routes known as geothermal hotspots are available to access this power source.

Geothermal hotspots are volcanic features found all around the world. Basically, a hotspot is an area of reduced thickness in the mantle that transmits excess internal heat from the interior of the Earth to the outer crust.

These hotspots are well known for their unique effects on the surface, such as the volcanic islands of Hawaii, the mineral deposits and geysers in Yellowstone National Park, or the hot springs in Iceland and New Zealand. These geothermal hotspots can be used easily to generate electricity.

   

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Tidal Power

Even the power of the tides can be harnessed to produce electricity. Similar to the more conventional hydroelectric dams, the tidal process utilizes the natural motion of the tides to fill reservoirs, which are then slowly discharged through electricity-producing turbines. The largest tide changes in the world are found at the Bay of Fundy located between New Brunswick and Nova Scotia. Tide changes of up to 17 metres can occur. Below is a picture of a dam in the Bay of Fundy.

Water Power

Hydroelectricity comes from damming rivers and using the potential energy stored in the water. As the water stored behind a dam is released at high pressure, its kinetic energy is transferred onto turbine blades and used to generate electricity. This system is enormously expensive to build, but it has relatively low maintenance costs and provides power quite cheaply.