Non-renewable energy is energy derived from sources that are finite in nature. This means that one day we will run out of energy from non-renewables. The most common non-renewable energy resource is fossil fuels. Fossils fuels like coal are burnt to supply energy for various activities. The use of non-renewable energy leads to pollution and degradation of the environment. 

Renewable energy, or clean energy, comes from natural sources that are being constantly replenished. The processes that give rise to renewable energy can never cease to exist. Solar and wind are the two most popular forms of renewable energy. We can say that they are renewable because the sun shines every day, and the wind blows constantly. 

Oil: Formation and Exploration

The first non-renewable resource that can also be considered the primary energy source in today’s world is Oil. Oil is a fossil fuel formed when ancient dead plants and algae sank to the sea or ocean floor. Here they were buried under sediments for millions of years. Therefore over time, due to the heat and pressure associated with continuous burial, their remains were converted into what we today call oil or petroleum.

Oil exploration is the search by an organization for petroleum deposits. It involves two key processes:

1. Locating sites that could potentially contain oil
2. The drilling of wells to extract oil from the site.

A geological survey is important to obtain data about the subsurface. After that, Geologists use this data to communicate the potential presence and size of the oil reserve under the surface.

Natural Gas

Natural gas is another fossil fuel that was formed the same way oil did. Plants and animals remain buried for millions of years under high heat and pressure. Methane (CH₄) is the most popular natural gas. Natural gas and oil commonly occur in association. It is often found dissolved in oil at high-pressure reservoirs. Based on their mode of occurrence, natural gas is divided into three types:

1. Conventional natural gas is found trapped in large cracks in rocks or spaces between rocks.
2. Unconventional natural gas occurs in the tiny pore spaces of sedimentary rocks like shale and sandstone.
3. Associated natural gas is natural gas that is found along with deposits of oil.

Note: Associated gas is also sometimes called ‘wet gas’ due to its association with oil. ‘Dry gas’ is natural gas found not associated with oil.

https://www.eia.gov/energyexplained/natural-gas/

Note: The process of formation of natural gas, oil, and coal is the same.

Liquefied Petroleum Gas

Liquefied Petroleum Gas (or LPG) is a gas that is converted to a liquid under low pressures. LPG is not normally stored in its natural gaseous state. It is always distributed to consumers in its liquid state. LPG is a highly flammable gas and can burn when ignited. It commonly contains a mixture of butane and propane. There are many different commercial and industrial applications that use LPG. LPG is used in cooking gas stoves, ovens, heaters, and fireplaces. Its industrial applications include hot air balloons.

Compressed Natural Gas

Compressed Natural Gas (CNG) is natural gas, methane, that has been compressed to less than 1% of its volume. It is today popular as an eco-friendly alternative to diesel and other fuels used in vehicles. CNG is non-toxic to the environment, and its use can decrease carbon monoxide emissions by 90-97%. Vehicles that run on natural gas create much less noise pollution than those that run on diesel. It is one of the cleanest fuels in the market today. The use of diesel leads to the release of tiny soot particles in the air that cause asthma and other respiratory diseases. Swapping diesel for CNG can reduce the number of respiratory diseases contracted and decrease air pollution.

Coal Reserves and Coal Gasification

As of 31^st December 2020, the world had 1,156 billion tons of coal reserves. The top five countries that contain most of the world’s coal reserves are:

1. United States of America – 22%
2. Russia – 15%
3. Australia – 14%
4. China – 14%
5. India – 15%

The world has around 133 years of coal reserves left. (Note: Undiscovered reserves of coal being not  )

Even though coal is more abundant and cheaper than natural gas and oil, it releases much more carbon dioxide into the atmosphere when used. Coal gasification is a green technology that converts solid coal to gas. The gas can further be converted to electricity, hydrogen, and other energy products. Coal is converted to gas under heat and pressure and by breaking it down into its chemical elements. The ‘syngas’ produced as a result of this process is made up of primarily carbon monoxide and hydrogen. Coal gasification is a green technology because the gas can be used more than once.

Environmental Impacts of Non-Renewable Energy Consumption

Energy consumption defines the total amount of energy that the world’s populations use. It is a measurement of energy usage from all sources. The International Energy Agency (IEA) has set a goal of limiting the warming of the planet to 2⁰C. This goal has become increasingly difficult to achieve each year as governments, agencies, and corporations do not take necessary actions. A large portion of the emissions that contribute to a warming planet comes from the use of non-renewable energy sources, i.e., fossil fuels. The use of fossil fuels comes with a range of damaging environmental impacts such as:

• It emits carbon dioxide and methane, which greatly contribute to a changing climate.
• Air pollution is due to the release of mercury, sulfur dioxide, and other particle matter. These cause irreparable damage to plant and animal species, further causing a loss of biodiversity. Air pollution also negatively affects public health.
• Oil spills from leaks in pipes or wells in seas. Not only do they harm marine fauna and flora, but they also cause economic losses to island countries and regions along the coast that benefit from tourists.

Future Energy Options and Challenges

We depend on a continuous supply of energy to maintain our quality of life. Therefore, with a severely changing climate, it has become important and urgent to implement practices that utilize renewable forms of energy. Experts have predicted that in the next five years, there will be an increase in the use of energy derived from wind and solar power plants. The price of these forms of energy is reducing every day due to the long lifetime of such energy projects. Governments worldwide offer subsidies to people looking to install solar panels on their roofs. With the decreasing cost of renewable energy, corporations will directly sign contracts with solar and wind power plants for their energy supply.

However, even with the cost of renewables predicted to decrease, there is still (and will be) a large section of the population that continues to rely on fossil fuels. Estimations have placed the world’s energy consumption to have increased by 50% by the year 2040. The cooling of the planet is going to be the biggest challenge for governments and world leaders.

Renewable Energy Resources

Renewable energy comes from sources that are replenished naturally. They are inexhaustible sources of energy. Below are a few renewable sources:

• Solar: Solar is, by far, the most popular renewable source of energy. Solar panels capture the heat and radiation from the sun and then converted it to electricity.
• Wind: Generated due to uneven heating of the Earth’s surface. Windmills are equipment that captures the energy from wind and converts it to electricity.
• Geothermal energy: Geothermal energy is the heat present within the Earth’s interior. By the use of this energy, we can heat water in storage and generate electricity.
• Hydropower: Derived from moving water. Hydropower plants convert mechanical energy into electrical energy.