The 21st Century is likely to be the century in which mankind finally exploits renewable energy sources to their full potential. The joint concerns of global warming and the dangers of economic dependence on fossil fuels have already pushed many nations to explore alternative methods of power, such as using wind turbines and solar panels. Scientists are also striving to improve ways of harnessing other natural energy sources such as marine algae and organic waste materials. This piece will look at the top 10 forms of renewable energy.
The ability of waves to travel large distances without losing energy makes them a potential source of renewable power. Mankind’s attempt to harness the power of waves is still in its early stages and various types of experimental offshore wave farms have been developed across the world. Another way in which the world’s seas and oceans can be used to generate electricity is through tidal power. This alternative energy source involves taking advantage of the energy released by the ebb and flow tides, which are created by the moon’s orbit around the earth.
Hydrogen is the most abundant element in the universe. This gas is used to propel rockets in the space industry and can be utilised to power everyday vehicles such as cars and buses. It has also been used in the development of rechargeable batteries. Its main drawback is that it is highly flammable. Presently, it is extracted from fossil fuels, but in the future it could be produced as a renewable and inexhaustible source of energy. Several car manufacturers are now producing vehicles that run on hydrogen, with some experts predicting that it will one day replace petroleum as the main source of fuel.
Wind power exploits the kinetic energy produced by currents of air using turbines. It is a widely used but controversial form of alternative energy. Large wind farms are often needed to generate electricity that can be used on a wide scale and many people complain that they negatively impact on ecosystems and spoil the beauty of natural landscapes. Smaller scale turbines, which have a minimal visual impact, can be employed on private properties as a method of contributing to the household electricity supply.
Geothermal power is the harnessing of thermal energy released by the earth. It is a very economical resource and completely natural. The process does release gases that are said to contribute to global warming but the levels are still much lower than those created by the burning of fossil fuels. Indeed, geothermal power could actually help significantly cut carbon dioxide emissions if deployed on a wide scale in place of fossil fuels. The equipment used to gather thermal energy is installed below ground and thus does not have any visual impact. One of the most efficient methods of harnessing thermal energy is drilling in areas with water as this element is a good conductor of heat.
When fresh water in rivers mixes with salt water from seas and oceans large amounts of energy are released. This type of alternative energy is known as osmotic power, salinity gradient power or blue energy. The process of harnessing this energy by combining the different forms of water is still in the experimental stage and only a few osmotic power stations have been built across the world. Such power stations, ideally placed at river months flowing into the sea, can be built partially or totally below the surface, thus minimising the visual impact on the local environment. A possible environmental drawback to the process is the discharge of water with high salinity levels which could negatively impact on plants and animals.
A number of technologies have been developed to convert the organic waste into energy. One method involves the collection of the methane gas that is released during the decomposition process. Methane can be used as a fuel to run vehicles or power motors that generate electricity. The gas is burnt and disappears during this process. Power plants which harness biogases can be run at a relatively low cost.
Cooking oil pollutes the environment if it is poured down the drain after use. Experts recommend that you place residual cooking oil in bottles before disposing of it at recycling centres. Various processes have been devised to convert cooking oil into a sustainable energy. Even though its production is more expensive than the processing of hydrocarbons, the main advantage of its use is that it is a renewable source of energy. Tests have already shown that biodiesels can be used to completely or partially power vehicles ranging from aeroplanes to buses.
The fermentation of sugar results in a compound that can be used as fuel called bioethanol. However, this method of producing energy has proved to be very controversial. For some experts, bioethanol is a sustainable energy source that offers environmental and economic advantages when compared to fossil fuels. However, many environmentalists argue that it leads to deforestation as producers seek to create more agricultural land in order to cash in on demand. Others have argued that the use of sugar to make bioethanol causes rising food prices. Vehicles in many countries are already run on bioethanol and the United States and Brazil are the world’s main producers of the fuel.
Research is currently ongoing into finding a cost-effective way of processing algae into a biofuel. One of the main advantages of algae is that it can be found in almost any type of aquatic ecosystem. Drinking water is not used in its cultivation and it can be placed in any type of soil. The metabolism of algae is based on capturing carbon dioxide and sunlight for growth. Thus while carbon dioxide is released when algae is brunt as a fuel, the effects are counteracted by harvested algae which removes this greenhouse gas from the atmosphere.
The energy that we receive from the sun is more than enough to satisfy the entire world's power needs. Its use by mankind as a power source dates back to ancient times and it is currently one of the most widespread forms of renewable energy. Electricity production can be achieved using solar radiation to heat liquids which in turn produces steam that turns turbine generators. Another method is through a process known as photovoltaics. This involves solar energy being converted directly into electricity. The cost of this process has decreased with technological advances, making it competitive with conventional energy sources.