There are various sources of energy that are used for generating power. Today, many new forms of energy sources are being discovered but none of them can be used to provide the power to help modern life function. Some of the forms of renewable energy are explored in this section.
HYDROPOWER
Hydropower is an efficient form of energy source wherein a single plant can generate more electricity than 1000 wind turbines. This form of energy is emission-free. However, there are problems that do arise because the building of hydropower plants requires huge acres of land. In Brazil, the Belo Monte dam will flood virgin Amazonian forest. In China, the Three Gorges Dam resulted in the displacement of a million people. Flooded vegetation and soil at the bottom of the reservoir can decompose to release methane gas – each molecule of which traps 25 times more heat energy than carbon dioxide.
SOLAR
The decreasing cost of solar panels means that it is becoming an increasingly viable alternative to fossil fuels. Solar energy is another efficient and sophisticated form of energy which is used. Solar farms can be built on less productive land. Some of the problems associated with solar energy is that it cannot be used in places where there is no direct source of the sun. At night time when electricity demand can peak, solar power cannot help – unless it has been stored from the day using batteries or some other form of storage technology.
WIND
Wind farms are also becoming more popular as the price of the turbines decreases. Wind turbines produce electricity whenever enough wind is blowing, unlike solar, but are unable to respond to peaks in demand or at times of low wind. Onshore wind farms typically make good use of land and offshore wind farms can also often be situated close to large cities, thus reducing the cost and inefficiency of transmission. The London Array is the largest offshore wind farm in the world and is under 100 km from London. However, expansion was stopped due to the impact on migratory birds that can be killed by the turbines.
GEOTHERMAL
Geothermal energy is derived from the Earth’s internal heat. On a large scale, underground reservoirs of steam and hot water can be tapped through wells that can go a mile deep or more to generate electricity. Unlike solar and wind energy, geothermal energy is always available, but it has side effects that need to be managed, such as the rotten egg smell that can accompany released hydrogen sulphide.
NUCLEAR ENERGY
About 11 per cent of the world’s electricity is generated through Nuclear Energy. Countries like United States, France, China, Russia, and South Korea generate the most nuclear power. Nuclear energy is an emerging renewable energy source which powers space exploration, sterilizes medical equipment and provides potable water through desalination.
