Natural Gas

Odorless, invisible natural gas is perhaps dangerously mysterious. In fact, manufacturers have long added a distinctive sulfuric scent to the fuel so that consumers can more easily detect a leak. Although we can’t see it, touch it, or smell it, it has a huge effect on our daily lives. Where does it come from?

Like its fellow fossil fuels, natural gas is the result of organic matter that has been crushed under layers of sand and rock and left to compress and heat up by the warmth of the earth’s core for hundreds of millions of years. So, what causes organic material to become natural gas instead of coal or oil? First, the type of organic material. Generally, the more of the organic material (dead organisms) that developed into a fossil fuel was plants, the more likely it is to develop into coal. If the organic material was mostly animals, it is more likely to become oil or natural gas. So, while coal deposits develop mainly from ancient swamplands, natural gas and oil deposits originate from what used to be the sea floor.

What causes the same organic material to develop into natural gas instead of oil? A couple of factors. If the organic material – or biomass – on the sea floor had a higher proportion of dead plants compared with dead animals, it’s more likely to develop into natural gas. Likewise, more heat produces lighter oil – and even more heat than that produces natural gas. That’s why natural gas deposits and oil deposits are so often one and the same. Natural gas rises above a layer of oil, or finds its way into pockets of porous rock.

How does Natural Gas create energy?

Natural gas can produce electricity and heat. It’s not uncommon for industrial and commercial sites to use it for both electricity and heat, which is particularly efficient. To convert it into electricity, power plants use one of three methods: a steam generation unit, gas turbine, or a combination of the two.

In steam generation units, the natural gas is burned in a water boiler to produce steam. The steam turns a turbine, which powers a generator. In gas turbines and combustion engines, the heat produced by burning natural gas powers a turbine directly. Steam generation units are a bit more efficient than gas turbines, but the most efficient type of unit combines both these methods. In combined cycle units, a gas turbine generates heat to power a generator directly. Meanwhile, a steam generation unit picks up any excess heat from the gas turbine and uses it to heat water into steam.

What’s the environmental cost of Natural Gas?

As far as fossil fuels go, the processing of natural gas is efficient and clean. Natural gas power plants emit carbon dioxide – the greenhouse gas that causes global warming – at a rate up to 60 percent lower than that of a typical coal plant.

Drilling and transportation is a different story. Aside from damaging local ecosystems, the extraction of natural gas runs the risk of methane leaks. The same holds true of transporting it through pipelines. And methane is a more powerful greenhouse gas than carbon dioxide, trapping heat at a rate 86 times stronger over a period of 20 years. To avoid leaks, energy companies and government initiatives would need to invest in stronger precautions. We don’t prevent them effectively enough now to offset the environmental cost, but it is possible.

What are its common uses?

As of 2011, natural gas accounted for 30 percent of energy consumption in the United States. Our use of natural gas has not been declining – in fact, we tend to use more of it than we produce domestically every year. Policy tends to see natural gas as the lesser of three evils, the only clean-burning fossil fuel, so it’s relatively popular. Most of natural gas use (about 38 percent) is electricity production, but it’s also a big industrial fuel source, with another 30 percent of our use of the fuel in industrial sites. Other uses include residential (17 percent) and commercial (12 percent), according to data from the Energy Information Administration.

How much does Natural Gas cost?

Natural gas is vying for coal’s position as the cheapest fossil fuel, and government regulation, fueled by public opinion, seems to be making it so. Over the past decade, natural gas has crept closer and closer to coal’s low price as the price of coal has steadily increased. This trend is projected to continue, with regulations and incentives rewarding natural gas plants’ lower carbon dioxide emissions.