The fossil fuels are formed due to the gradual decomposition of plants and animals remains which get buried deep into the surface of the earth. This process takes over hundreds of millions of years to get converted into fossil fuel. The fossils fuels are termed as non-renewable resources of energy because our rate of consumption is much higher than their rate of formation or re-cycling.
The three primary sources of fossil fuels are Coal, Petroleum and Natural gas, which are used to generate electricity and are used in mass transportation.
The total energy demand of the world as on year 2014 is 5.4 quadrillion BTU or 5.4 x 1017 BTU (British Thermal Units), and around 77% of this demand is met through non-renewable energy resources, whereas the renewable energy resources (including Hydro) are collectively providing around 23% of the total energy demand and the share of solar energy in the total energy consumption is around 1 %
(1) Any-time availability:
The fossil fuels are extracted under the surface of the earth and this process is called mining. The mining is an expensive,time taking and labor intensive process of extraction of fossil fuels. But once, the fossil fuel is extracted and preserved, it can be used anytime and anywhere. For example:
(2) Energy efficiency:
It is the ratio of the useful energy generated to the total energy consumed by any system. The energy efficiency is generally expressed as Heat rate; it is the amount of energy used by the system to generate 1 KW-hr of energy. The higher efficiency of the fossil fuels as compared to the solar energy is another key driver of their heavy use. The efficiency of various energy sources are as follows:
You can calculate the efficiency of the solar panel using the following formula:
Let us take an example: The solar panel which produces 300 watt of power has the following dimensions:
(3) Fossil fuels are cost effective:
The per unit cost of energy generation by the fossil fuels are less as compared to that by solar energy. The technology used in converting solar energy into electrical energy is costly as compared to that of fossil fuels. The main component in the solar PV system is solar panel which converts solar energy into D.C. electrical energy and which is further converted in A.C. electrical energy through inverter to run our home appliances like fan, cooler, fridges etc.
Harmful effects of Fossil fuels
Although the fossil fuels are energy efficient and cost effective in comparison to their renewable counterparts but their burning is harmful both to the health and the environment. The following harmful effects and limiting factors have created a strong need for the alternate energy option:
(i) Increase in Green house effect:
Our earth receives energy from the Sun and its surface absorbs part of the energy resulting in heating of the earthâ€™s surface. It cools down by reflecting infra red radiations but green house gases (carbon-di-oxide, methane, water vapours, nitrous oxide) absorb some of it, resulting in warming of the atmosphere. The man made green house gases are CFC (Chlorofluorocarbon), HFC (Hydrofluorocarbon) & PFC (Perfluorocarbon). The use of fossil fuels have resulted in the increase in the green house gases which resulted in increase in temperature, approximately, a rise of 1 Degree Fahrenheit in the 20th century due to the heavy use of fossil fuels. The rise in the temperature is casing the melting of the ice in the Arctic region, Antarctica, which is resulting in the increase in the sea level. There is approximately 32,000 Mt of CO2 combustion in the year 2015
(ii) Air pollution
We burn fossil fuels to generate electricity and for transportation. The gases which are emitted by these fossil fuels have the hazardous effects on the health and the environment. The following are the main pollutants which are released upon burning of the fossil fuels:
(iii) Depletion of ozone (O3) layer
The ozone layer is present in the upper atmosphere of the earth called the stratosphere; it acts as a filter and protects us from the harmful ultraviolet radiations called as UV-B radiations. This effect was first detected in 1970 and the emission of Chloro fluorocarbons (CFC) is the main reason behind the depletion of the ozone layer.
The depletion or a hole in the ozone layer means that the harmful UV-B can pass through it and reaches the surface of earth. It can disrupt the biological processes leading to skin cancer, eye damage, affecting growth, early aging, and reduction in the immunity.
(iv) Fossil fuels are limited
Our energy demand is increasing with increase in the population and the rate of consumption of fossil fuels is much higher than the rate of recycling of fossil fuels. With this rate of consumption, the fossil fuels are expected to last for next 100 years or so. This limitation of fossil fuels has created the urgent need to search for the alternate energy option that can fulfill the growing energy needs.
(Data source: www.yearbook.enerdata.net)
The trend is shifting towards Renewable energy (Solar energy)
The harmful effects to the health and the environment by burning fossil fuels have made us to think seriously about it and search for the alternate energy option which is not only environment friendly but also a reliable energy resource and Solar energy is one of the options.
The solar power is effective in meeting energy demand and is one of the cleanest forms of energy with almost no harmful effects to the environment and is not hazardous to health. The use of solar energy will help in reducing the green house effect which otherwise is increasing with the use of fossil fuels. It is available to all the places of the earth without any effort whereas in case of fossils fuels, a labor intensive process called mining is required to extract them from underneath the earth. It can be utilized to generate electricity in difficult terrains like mountainous regions where providing conventional electricity is not economically feasible. The long life and less maintenance cost of the solar panels are making it a lucrative option for the energy source.
The prices of the solar panels are falling continuously since 1977 with average CAGR of 16% and are further expected to fall in future.
This will make solar energy more cost effective as the average cost of the solar power will further decline that will lead to increase in its demand.
The continuous use of fossil fuels has degraded the environment and has done an irreparable damage to it, resulting in melting of glaciers and increase in sea level due to increase in green house effect, acid rains, depletion in the ozone layer. The hazardous effects, of burning fossil fuels, to the health and the environment have attenuated or undermined the benefits of higher energy efficiency and cost effectiveness. Moreover, the environment friendly benefits of solar energy have compensated its lower energy efficiency and higher cost and has put it on the higher side of the paradigm vis-a vis fossil fuels.
Its long life, less maintenance cost and almost uniform performance has the capability to become cost effective in the long run. Moreover, the decreasing prices of the solar panels and the ongoing technological developments in solar photovoltaic field to further increase its efficiency and enhance the feasibility of the solar roof that will further accelerate its growth.