Why is energy trend shifting to Renewable energy?

Energy is the basic foundation of any nation and it determines its economic stability. Since prehistoric times man is using energy to fulfill his basic needs. Although, the renewable energy resource, the solar energy, is present since the inception of this planet and one can use solar electricity but the human being is using fossil fuels as the primary source of energy than the solar energy.

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 KW-hr = 3412 BTU

Yes, it is true that solar energy is available at free to all without making any efforts while fossil fuels need extraction from the underneath of earth’s surface but still these are used heavily. The following main reasons are responsible for their heavy use:

(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:

• You can drive your car at night
• You can cook any time

Whereas solar energy is only available in daytime when the sun is shining, its intensity varies every month, moreover during cloudy weather and in winters, its intensity is reduced and hence affects the performance the solar panels. Also, due to the rotation of the earth, the position of the sun keep on changing, therefore the angle and the orientation of the solar panels have to to be changed in order to receive maximum energy from the sun. Therefore, in order to keep energy available 24 hours of time, one need to keep the energy storage devices like solar batteries which can be charged through solar energy in day time and provide backup to the system during night and other times when the solar insolation is affected due to bad weather conditions.

(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:

S.No	Energy source	Energy consumed to produce 1 KW-Hr of energy	Efficiency
1	Coal	3.07	33%
2	Petroleum	3.14	32%
3	Natural gas	2.33	43%
4	Nuclear	3.06	33%
5	Solar	6.00	15% - 17%

 

You can calculate the efficiency of the solar panel using the following formula:

• Efficiency (%) = Output power from the solar panel/ 1000 Watts/m2 x Area of solar panel

Where 1000 W/m2 is the power received by the earth in the square meter of area when weather is clear and the sun is shining. The power received by the solar panel depends upon its dimensions that is Length x Breadth.
Let us take an example: The solar panel which produces 300 watt of power has the following dimensions:

• Length = 1.96 meters
• Breadth = 0.99 meter

The efficiency can be calculated as follows:

• Efficiency = 300 Watts/ 1000 Watts/m2 x (1.96 x 0.99) m2 x 100= 15.5%

That is the reason we don’t see many cars and the homes powered by solar energy.

(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 earth’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:

• Carbon mono oxide
  
• Nitrogen Oxide
• Ozone
• Sulphur di oxide
  
• Lead
• Mercury
• Particulate matter

These pollutants have following hazardous effect on the health and the environment:

• It affects lungs which lead to breathing and respiratory problems
• Asthma
• Eye, Nose and throat infections
• Affects immune system leads to lowering of immune system
• Reduces the oxygen supply in the blood
• Cancer
• Early aging
• Digestive problems
• Affects brains nervous system
• Damage crops and vegetation
• The gases sulphur dioxide and the nitrogen oxide reacts to the water molecules results in acid rain. Acid rain damages trees, vegetation, buildings, statues and monuments.
• Harmful to wildlife and aquatic life

(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.

• 1 Toe = 11630 KW-hr
  
• 1 MToe = 11630 x 106 KWhr or 1.163 x 1010 KWhr

A CAGR of around 2% increase per year
(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.

Conclusion:

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.

Related Articles:

• Future potential of solar energy in India
• How silicon solar cells generate electricity?
• What is your energy portfolio this summer?