By Kiran Gupta
In today's era of environmental consciousness, the efficiency of appliances within the home has come into question. Multiple US states have attempted to pass legislation removing natural gas hookups from new construction, but few have gone through. Removing natural gas hookups from homes will have implications with major appliances, including stoves, furnaces, and dryers. This begs the question; does phasing out gas appliances reduce our environmental impact?
So far, six states have successfully passed or are progressing with gas bans or electrification codes. California, Colorado, New York, Massachusetts, Vermont, and Washington have already passed measures and account for 24% of the national residential gas use and 20% of commercial use in 2020. Conversely, 20 states, representing 31% of combined residential and commercial gas use, have enacted laws prohibiting local restrictions on building gas usage.
To appreciate the drive for natural gas bans, it's essential to examine the corresponding environmental and health repercussions. The EPA reveals that residential and commercial emissions comprised 13% of total U.S. emissions in 2019, with around 80% originating from natural gas combustion. Found in approximately 60% of American homes, natural gas is a prevalent utility.
Indoor natural gas combustion poses health risks, including the release of harmful gasses like nitrogen dioxide, carbon monoxide, and formaldehyde. Studies, such as one from 1992, have linked such exposure to a 20% increase in children's respiratory illness risk. Lack of EPA regulations concerning indoor gas release further worsens the issue. Additionally, studies have found that stoves can leak natural gas, even when they are turned off. These leaks release benzene, a known carcinogen into the home.
Environmental groups make good arguments for phasing out gas stoves, but it is important to examine the true environmental impact of burning natural gas in homes, and the role of natural gas in the US. The average US household consumes between 70 and 90 therms per month of natural gas. That is up to 290 cubic feet of natural gas per day, equivalent to 2.28 gallons of gasoline. In the average car with a fuel economy of 25 mpg, one could drive up to 60 miles. The average American commute length of 41 miles per day uses less fuel than the equivalent natural gas used within a home.
Natural gas is used extensively in the US for energy production, making up 39.8% of total production. That is the single largest source of energy. Unless the US starts producing much more energy from renewable sources, replacing natural gas appliances with electricity just changes where the natural gas is burned - from the home to outside power plants. This helps to reduce unhealthy emissions in the home but ultimately uses more power.
Let’s take a look at heating a home with electricity. A natural gas power plant must first burn natural gas to create electricity. These power plants can range from 33% to 60% efficiency. Another 5-7% is lost in transmission on the way from the power plant to one’s home. Finally, the home furnace converts electricity to heat. On paper, electric furnaces are 100% efficient because they convert all electric power to heat, which is used to heat the house. However, using electricity to heat an entire house is very taxing, the furnace for the average house uses about 13 kWh of electricity. That is comparable to a Level 2 electric car charger. Home gas furnaces, on the other hand, can be up to 95% efficient. Natural gas is much more efficient at heating, as burning it creates heat. It is far more inefficient to burn natural gas at a power plant to create heat, then convert it to electricity, only to convert it back to heat at a house.
In 2022, the US produced 35.81 trillion cubic feet of natural gas. However, a large portion of that gas was mined unintentionally. When drilling for oil, natural gas deposits can be broken, causing the gas to be released. In fact, 20-25% of all natural gas is produced from oil wells. Reducing the demand for natural gas by removing it from buildings does not reduce the amount of gas produced, as long as oil production remains constant. In fact, the US already exports natural gas, these legislations would only increase exports, allowing other countries to burn the gas.
There are some methods that we can take to reduce the amount of natural gas emissions. When drilling for oil, natural gas is released. However, unlike oil, which is extracted in liquid form, natural gas is in gaseous form. This makes storage challenging and expensive. To prevent releasing volatile organic compounds into the air, it is burned, known as flaring. In 2022, the US flared 419.75 Billion cubic feet of natural gas. That is 23 million tons of CO2 emissions with nothing beneficial in return. For reference, all the passenger cars in the US produced 374.2 Million metric tons of CO2.
Capturing the gas released from these flares, or at least burning it for something useful, would significantly reduce the amount of useless CO2 produced. Researchers at MIT have developed a method of producing methanol, a liquid fuel with many uses, from natural gas on site at oil rigs. With free natural gas, methanol production would be roughly $1.00/gallon, much lower than the current market price. This allows for the excess natural gas to be used for something useful, instead of just burning it off. Other companies are attaching containers filled with bitcoin mines to these flares, taking advantage of the free energy while mining cryptocurrency.
In conclusion, the debate surrounding the use of natural gas in homes raises complex questions about efficiency, health, and environmental impact. While legislation seeks to phase out natural gas from new constructions, the broader implications on energy consumption, emissions, and alternative utilization of natural gas require careful consideration. Innovations in capturing or repurposing natural gas, as well as a balanced approach to energy sources, could forge a path towards a more responsible and sustainable energy future for all.