chapter  1
Solar Cells and Their Generations
Pages 54

Energy plays a very important role in the socioeconomic growth and energy security of a country. The U.S. Energy Information Administration’s Annual Review 2011 identified industrial, residential and commercial, transportation and electric power generation as the prime sectors for energy consumption that account about 21%, 11%, 28%, and 40%, respectively, of total energy consumption [1]. An almost similar report was presented by the European Commission on Energy in 2011, where transportation, industry, household, services, and agriculture were found to share 32%, 25%, 27%, 14%, and 2%, respectively, of total energy consumption. Most energy is drawn from the fossil fuels like coal, oil, and natural gases, which have been buried in the Earth’s crust for over millions of years. These fuels are formed from the remains of the dead plants and animals that are trapped and decomposed under the soil. In principle, these fossil fuels should be called renewable sources of energy, but because they take millions of years in generation and are depleting faster than their production, they are called nonrenewable. An estimate by the U.S. Energy Information Administration shows that a large percentage of energy is derived from fossil fuels where they share ~83% of world energy consumption, out of which petroleum, coal, and natural gases account for about 37%, 20%, and 26% shares, respectively. Nuclear energy is another nonrenewable energy that shares 8% of the world’s total energy consumption. The rapid depletion in fossil fuels and imbalance in the energy demand and supply is responsible for the hike in inflation rates. According to the 2011 annual report of the European Commission on Energy, to meet the energy demand 35.1% of energy was derived from petroleum and solid fuels accounted for 15.9% of energy. Nuclear power and natural gases accounted for 13.5% and 25.1%, respectively, whereas 9.8% of total energy consumption was derived from renewable sources. The world’s energy consumption is increasing very rapidly in every sector of day-to-day life. Fossil fuels are limited in quantity and the population growth is adversely causing rapid reduction in the available energy per capita. Regular consumption of fossil fuels is expected to have severe harmful effects on the climate. Worldwide use of fossil fuels produces a billion tons of CO2 (a greenhouse gas), which causes an increase in the Earth’s surface temperature and contributes to serious concerns like global warming and climate change. Additionally, the combustion of fossil fuels increases environmental pollution, which has very harmful effects on the health of every living being. For example, in 2013 the pollution in the city of Harbin, China, due to coal-powered plants increased to more than 40 times than the set daily target by the World Health Organization [2], which led China to take some serious steps toward minimizing the use of fossil fuels and use of alternate

energy sources. In order to prevent pollution and the climate change, the use of alternate energy sources like renewables is now required. China started investing a large sum of money in the development of renewable energy and it has now become the biggest investor in the world for renewable energy production.