Introduction to Energy – Energy resources and forms of Energy-Renewable Energy and Non-renewable energy- Scope

Energy resources

World energy resources can be divided into fossil fuel, nuclear fuel and renewable resources. The estimates for the amount of energy in these resources is given in zettajoules (ZJ), which is 10²¹ joules.

Fossil fuel

Reserves of fossil fuel are estimated as:

S.no	Fuel	Energy reserves  (ZJ) (2009)
1	Coal	19.8
2	Oil	8.1
3	Gas	8.1

 

Scope of renewable and non renewable sources of energy

Non-renewable energy sources are those sources that drain fossil reserves deposited over centuries resulting in depletion of these energy reserves. These energy cannot be replenished with in human lifespan. The main non-renewable energy sources are coal, oil and natural gas

1. Coal : Coal is the most abundant form of fossil fuel available on earth. They were formed by the decay of old plants and animals several centuries ago. coal is major source of fuel for electricity generation as of today. Most power stations on earth require huge reserves of coal to produce electricity continuously without break. When coal is burnt, it produces heat that is used to convert the water into stream. Coal contains excessive amount of carbon. When it is burnt to produce power, it mixes up with oxygen to produce carbon dioxide. Carbon dioxide is one the gas responsible for global warming. The use of coal and other fossil fuels have only increased since they were discovered. Their excessive extraction and use has resulted in degradation of environment and ecological imbalance. Though coal is still available in big quantity on this earth but it is predicted that it won’t last for more than 40-50 years if switch is not made to green or clean energy.

According to the International Energy Agency the proven reserves of coal are around 909 billion tonnes, which could sustain the current production rate for 155 years, although at a 5% growth per annum this would be reduced to 45 years, or until 2051. With the Fischer- Tropsch process it is possible to make liquid fuels such as diesel and jet fuel from coal. In the developed countries, 49% of electricity generation comes from burning coal.

2. Oil : Oil is available in abundance in most of the middle east countries including Saudi Arabia, Kuwait, Iran, Iraq and UAE while some limited oil wells are present in North America and Canada. Most of the countries still have their huge dependency on these countries for their oil requirements. Like coal, it was also made out of dead plants and animals that had lived millions of years ago. When plants and animals died they were covered with thick layer of mud and sand which created huge pressure and temperature. These fossil fuels coal, oil and natural gas are result of those conditions only.

Wide usage of oil and oil related products has resulted in massive air pollution. It is a major source of fuel that is used in vehicles. Due to the process of combustion, harmful gases like carbon dioxide are released when oil is burnt. Everyday around 19.7 million barrels of oil is consumed in United States alone. Oil is transported to other nations using pipelines or ships. Leakage in ships leads to oil spill which affects animals and plants that live inside or around the sea. Just couple of years back, a ship containing oil of British Petroleum (BP) caused oil leakage which resulted in killing of many whales, fishes and small animals that live inside the sea.

It is estimated that there may be 57 ZJ of oil reserves on Earth. The peak of extraction will occur in 2020 at the rate of 93-million barrels per day (mbd) resulting in severe price increase.  The antithesis of sustainability is a disregard for limits, commonly referred to as the Easter Island Effect, which is the concept of being unable to develop sustainability, resulting in the depletion of natural resources. The  estimate, assuming current consumption rates, current oil reserves could be completely depleted by the year 2050.

 

3. Natural Gas : Natural gas is a mixture of several gases including methane, ethane, propane and butane. It burns completely and leaves no ashes. It causes almost no pollution and is one the cleanest form of fossil fuel. Of these gases, methane is highly inflammable. It has no color, taste or odor. This is the reason that some chemicals are added to it before it can be supplied to individual homes so that a leakage can easily be detected. Middle Eastern countries particularly Iran and Iraq hold high reserves of natural gas. The beauty of this source of fuel that it causes almost no pollution, cheap and environment friendly.

 

4. Nuclear Energy : Nuclear energy is has become a hot technology today. More and more countries are switching to nuclear energy to fulfill their future energy demands. Around 16% of world’s electricity production comes through nuclear energy. Nuclear power plants use Uranium as a fuel to extract energy from it.

The energy can be released through either of the two processes: Nuclear Fission or Nuclear Fusion. Nuclear fission is the most common technique to harness nuclear energy. U-235 element is bombarded with slow moving neutrons which break the atom and releases energy. The atoms that got split are then again hit by neutrons to produce mass amount of energy. Like fossil fuels, nuclear does not produces any greenhouse emissions. Nuclear power plants produce some sort of nuclear waste called radioactive elements.

These elements emit strong radiations and must be buried deep underground so that they don’t affect human life. Couple of nuclear disasters has already occurred in past including Chernobyl and Island Three Miles. In the recent past, there is the case of the disaster, which happened in Japan back in 2010. These disasters have again raised several questions on safety of nuclear power plants and people who work in these plants. Despite this, several power stations are coming up in different parts of the world. Another downside of nuclear energy is that it can be used to make nuclear bomb. Therefore, these remain targets for various terrorist organizations.

The International Atomic Energy Agency estimates the remaining uranium resources to be equal to 2500 ZJ. This assumes the use of breeder reactors, which are able to create more fissile material than they consume. IPCC estimated currently proved economically recoverable uranium deposits for once-through fuel cycles reactors to be only 2 ZJ. The ultimately recoverable uranium is estimated to be 17 ZJ for once-through reactors and 1000 ZJ with reprocessing and fast breeder reactors.

Scope  of Non-Renewable Energy Sources

Non-renewable energy sources have fueled the world’s industrial complex for far too long. It has reached a point where the word is facing rapid starvation in this sector. There are also other associated effects too which also need to be carefully looked at just to make sure things are running as intended. However, this is not the case. With increased exploitation of these fossil fuels, there are many associated environmental effects like land pollution and air pollution which in turn affect both animal and plant life. The far-reaching consequences of non-renewable sources are inexplicable and the trend has to be reversed soon before it is too late to do anything.

Carbon is a major source of fuel in non-renewable energy sources. When combustion takes place, carbon is mixed with oxygen and form carbon dioxide. It pollutes the environment and is responsible for global warming. In last few years, the concentration of carbon dioxide has only increased in the atmosphere. Not to mention, climate change, acid rain and change in seasons are some other effects that has been observed by many people. With so many problems, scarce resources and rising prices, these resources cannot be used for lifetime. The need of the hour is to look for some alternative sources of energy and protect our environment from such harmful gases.

Renewable Energy Sources

Renewable resources are available each year, unlike non-renewable resources, which are eventually depleted. A simple comparison is a coal mine and a forest. While the forest could be depleted, if it is managed it represents a continuous supply of energy, vs. the coal mine, which once has been exhausted is gone. Most of earth's available energy resources are renewable resources. Renewable resources account for more than 93 percent of total U.S. energy reserves. Annual renewable resources were multiplied times thirty years for comparison with non-renewable resources. In other words, if all non-renewable resources were uniformly exhausted in 30 years, they would only account for 7 percent of available resources each year, if all available renewable resources were developed.

Solar energy

Clean, replenished, sustainable and widely available. Renewable energy sources are even larger than the traditional fossil fuels and in theory can easily supply the world's energy needs. 89 PW of solar power falls on the planet's surface. While it is not possible to capture all, or even most, of this energy, capturing less than 0.02% would be enough to meet the current energy needs. Barriers to further solar generation include the high price of making solar cells and reliance on weather patterns to generate electricity.

Wind power

The available wind energy estimates range from 300 TW to 870 TW. Using the lower estimate, just 5% of the available wind energy would supply the current worldwide energy needs. Most of this wind energy is available over the open ocean. The oceans cover 71% of the planet and wind tends to blow more strongly over open water because there are fewer obstructions.

Wave and tidal power

At the end of 2005, 0.3 GW of electricity was produced by tidal power.^[30] Due to the tidal forces created by the Moon (68%) and the Sun (32%), and the Earth's relative rotation with respect to Moon and Sun, there are fluctuating tides. These tidal fluctuations result indissipation at an average rate of about 3.7 TW. The total power of waves that wash against our shores add up to 3 TW.

Geothermal

The estimates range from 35 to 2000 GW of electrical generation capacity, with a further potential for 140 EJ/year of direct use.  The total heat content of the Earth is 13,000,000 YJ.

Biomass

Hydropower

In 2005, hydroelectric power supplied 16.4% of world electricity, down from 21.0% in 1973, but only 2.2% of the world's energy

Even after several years, share of renewable energy in world power production is less than 20%. It is however believed that by 2020, renewable energy will have a major share in world’s electricity production.

Coal mining as predominant as it is, should be limited to save the environment from many other associated effects aside from pollution. This was the major energy source in the early 19th century before plans were made to tap into renewable energy sources. Oil exploration was once the best trade and investment to make.

Nowadays, any discovery is just an environmental disaster in waiting. Geothermal power is another one that gives out lots of energy. The one bad thing is it is a non-renewable source of energy that has vast environmental effects. When carbon monoxide is released in the air, it bonds with oxygen resulting in reduction of percentage of oxygen in that specific area. This is a gas that has the capability to suffocate as it deprives oxygen from its surrounding to form carbon dioxide.

Hints  

1.   As of December 2013 the installed capacity of wind power in India was 20149.50 MW,^[1] mainly spread across Tamil Nadu (7162.18 MW), Maharashtra (3021.85 MW), Gujarat (3174.58 MW), Karnataka (2135.50 MW), Rajasthan (2684.65 MW), Madhya Pradesh (386.00 MW), Andhra Pradesh (447.65 MW)

2.   Muppandal wind farm in Tamil Nadu  is the largest wind farm in india with a current capacity of 1500 MW where as Jaisalmer wind farm is the second largest wind farm situated in Rajasthan with a current capacity of 1250 MW

3.   Thar Desert has been set aside for solar power projects, sufficient to generate 700 to 2,100 gigawatts

4.   Welspun Energy 151MW Neemuch Solar Project – Neemuch, Madhya Pradesh (151 GW.h year^-1)

5.   Charanka Solar Park – Charanka, Gujarat (214 GW.h year^-1)

6.   The energy consumption in India is the fourth biggest after China, USA and Russia.