As the reserves of nonrenewable fossil fuels like natural gas and petroleum is fast depleting, focus has been shifted to the alternative sources of energy like wind, solar and tidal energy. In the United States , fossil fuels meet 81.6% of the total energy supply, and only a 7.3 % of energy needs are catered by the alternative sources of energy. However, these energy sources are nonpolluting and non-diminishing, which makes it a dependable source of energy in the years to come. It is estimated that the fossil fuels will be largely used up within the twenty-first century, which has brought back the focus on alternative sources of energy for a sustainable global economy.
By endorsing the Kyoto protocol, which spells out an action plan to reduce fossil fuels in a phased manner, many countries in the European Union have reiterated their commitment to shift away from nuclear and fossil fuels- both detrimental to the environment. As a first step, these countries have set an initial goal of generating 12% of its total energy and 22% of its electricity from renewable sources by 2010.
Solar energy is probably the most convenient energy source, which can be utilized as heat or can be converted to electricity using photovoltaic cells. It is a cost effective and non polluting energy source that can be used for heating and lighting homes, offices and streets. Greenhouses and solariums are common examples of the direct use of solar energy,
Tidal energy is another promising source of renewable energy. Water when passed through turbines electricity can be created and it is a clean and renewable source of energy.
Wind power is one so the most ancient forms of energy harvested by man and a windmill can convert it into mechanical energy which can be converted into electricity using generators. The power generation cost in wind energy is slightly higher than hydropower and lower than nuclear power. Alternative energy sources will be the corner stones of the future economy and these cheap and eco friendly forms of energy need to be harvested fully.