Natural gas is a colorless, odorless mixture of hydrocarbons, consisting mostly of saturated light paraffins like methane and ethane.
As coal and oil are being demonized for their carbon emissions, natural gas has gained in popularity due to its lower carbon footprint. Though usually considered a fossil fuel, natural gas can also be made from renewable sources.
Natural gas is an abundant energy resource, especially in the United States. It accounts for almost 30% of energy consumption in the US, out of which 40% is used to generate electricity. The bulk of the remaining 60% is used for cooking, heating, and meeting industrial energy needs.
Though natural gas is a reliable and pollution-free alternative to fossil fuels to power vehicles, only a minuscule 1% of it is used in transportation. When compared to diesel vehicles, the pollution and carbon emission of natural gas-run vehicles is minimal.
With newer discoveries and improvements in technology, natural gas production is at an all-time high in the US. It is now the world’s leading producer of natural gas and can meet its natural gas demands from domestic supply.
Moreover, the US Energy Information Administration estimates that the country holds 6,800 trillion cubic feet of natural gas reserves, which will last for the next hundred years, accounting for the same rate of consumption.
Natural gas is relatively clean, efficient, cost-effective, and abundant. But does this mean we should continue to use it? This article takes a look at the pros and cons of natural gas.
How is natural gas extracted?
Natural gas occurs in the crust of the earth when the remains of plants and animals decompose under the ground. It typically is found in shale and other kinds of sedimentary rock formations. Sound waves and gravitational pulls are used by experts to detect the presence of natural gas underground.
Once identified, deep wells are dug in the ground to reach the natural gas reserve, usually at a depth of around 6,000 feet. Pipelines are used to extract the gas. The extracted gas is transported to power plants for further processing and distribution.
As of now, we have been extracting natural gas from reserves near the earth’s surface. Most probably the gas formed much deeper down and rose up through permeable rocks. Wherever the gas encountered impermeable geographical formations, such as sedimentary rocks, it got trapped and formed reservoirs.
However, deeper down there must be vast reserves of natural gas. We just need the technology and expertise to extract it.
Another form of natural gas is the renewable kind formed by the anaerobic decomposition of organic matter. Biogas can be produced from dead plants and animals, animal waste, sewage, and industrial byproducts. This typically contains less concentration of methane but still can work the same way as extracted natural gas.
Natural gas energy: Pros and Cons
Advantages of natural gas
1. It is abundant.
As the data detailed above, the United States has abundant known reserves of natural gas. At the current rate of consumption, it will last us for 100 years. As the US can meet its natural gas demands from domestic supply, it helps with energy self-reliance.
2. It is economical.
The presence and abundance of natural gas closer to the earth’s surface and the current technology used in its extraction make natural gas an affordable source of energy. The estimated cost of natural gas that is available for extraction and use in known reservoirs is just around $3 per cubic foot. Natural gas prices have always been lower than that of gasoline.
3. It is convenient.
Natural gas, unlike the other two fossil fuels, is versatile in its uses. It can be used for a variety of domestic needs like cooking and heating. Besides, it can be used for electricity production and in vehicles as compressed natural gas (CNG). It has a wide range of applications in industries as well. One of the biggest advantages of natural gas is that it can reach the consumer through pipelines.
4. It is safe.
Natural gas is non-toxic, ie, not poisonous if inhaled in well-ventilated settings. However, in confined spaces, if it leaks and displaces the air, death by suffocation is a possibility. Consumers also need to remember that it is inflammable. So, it is also a fire hazard. If protocols are followed, natural gas is a safe fuel in domestic as well as commercial and industrial settings.
5. It is efficient.
Natural gas is considered more efficient than the other two fossil fuels, oil and coal. The efficiency of a fuel source is measured by the amount of energy generated per unit. Methane burns more efficiently than coal as undesirable byproducts are minimal. This also means less pollution. Natural gas has an efficiency of 92%, compared to 29% for coal and 31% for oil.
6. It is more eco-friendly than fossil fuels.
As natural gas burns more efficiently than coal and oil, less of it gets wasted away unlike fossil fuels. This means fewer carbon emissions and less air pollution. The combustion of natural gas doesn’t give rise to fumes, soot, or dust. Among the fossil fuels, natural gas is the most preferred as it is the cleanest and greenest of the three.
7. It has an infrastructure in place for use.
We have been using natural gas for the last couple of centuries. The technology and infrastructure already exist and are well-developed, making it easier to harness and use it. This means it is easier to ramp up its use in domestic, commercial, and industrial settings without too much investment.
8. It is easier to transport.
In its gaseous form, natural gas is easily transported through pipelines. Though it can be transported in containers, due to its expanded volume, it is not cost-effective. If transportation by pipeline is not a feasible option, usually natural gas is transported in its liquified form. Whether across oceans or by road, liquified natural gas is easier to transport in containers.
Disadvantages of natural gas
1. It is nonrenewable.
Being one of the fossil fuels, natural gas is a nonrenewable energy source. This means that as we use up the known reserves, it doesn’t get replaced or replenished at the same rate. Just like other fossil fuels, natural gas needs millions of years and a special kind of geological conditions including high temperature and pressure for its formation. Even if it gets replenished in a million years, the rate of replenishment is not fast enough to maintain the same reserve capacity.
2. It is costlier to transport and store.
In comparison with oil and coal, natural gas is more expensive to transport. Laying pipelines is a high investment initiative. Besides pipelines, if it needs to be transported in gaseous form by land or across oceans, due to its large volume, the cost will be higher. Storage of natural gas is also expensive for the same reason. The volume of natural gas in its gaseous state is four times that of gasoline. Natural gas is usually transported in a liquified state to overcome this obstacle.
3. It has harmful byproducts.
On combustion, natural gas burns cleaner than the other two fossil fuels. This doesn’t mean that there are no carbon emissions. Natural gas combustion generates greenhouse gasses including carbon dioxide. However, if it is used to replace conventional fossil fuels, it can help in reducing the overall carbon emissions. Natural gas emits 30% less CO2 than oil and 45% less than coal.
Natural gas is mostly methane and this may leak into the atmosphere at the time of extraction or from the wells, storage tanks, pipelines, and processing plants. Methane, being a greenhouse gas, is harmful to the environment, leading to global warming and climate change.
At the time of extraction as well, natural gas creates environmental hazards. It is not possible to extract natural gas alone from the earth. The extracted mixture will contain hydrocarbons like ethane, butane, and propane and non-hydrocarbon components like sulfur, nitrogen, helium, carbon dioxide, and hydrogen sulfide. All these need to be removed before we can use natural gas.
4. It has to undergo a long and expensive refining process.
As mentioned earlier, natural gas is extracted as a mixture of various toxic and non-toxic components. All these need to be removed through tedious processing. This requires manpower and time and is expensive.
5. It is highly inflammable.
As methane is the primary component of natural gas, it is highly combustible. This makes it dangerous and risky at various stages of handling from extraction onwards. As the gas is colorless, odorless, and tasteless, it is hard to detect a leak, adding to the risk factor. However, as it is lighter than air, it disperses easily in the air, in well-ventilated places.
6. Its extraction affects the environment.
From exploration to drilling and production, the extraction process of natural gas harms the environment in multiple ways. Natural vegetation gets disturbed and destroyed and the soil gets contaminated and damaged. Drilling causes air pollution, besides creating disturbances for people and wildlife and contaminating water resources. Noise pollution is another problem for us to deal with.
Among fossil fuels, natural gas is the cleanest and cheapest and for the time being, highly abundant. As we try hard to shake off our dependence on oil and coal, natural gas is considered the first step toward a cleaner energy source.
Like everything else, natural gas also comes saddled with its own set of advantages and disadvantages. However, in the current scheme of things, natural gas is our best bet for a cheap, reliable, and cleaner source of energy.
But long-term prospects of the natural gas industry don’t look bright. We need to look for cleaner, greener, renewable, and sustainable energy sources – something better than natural gas.