Why Banning Gas Stoves Could Use Even More Gas

By OlegDoroshin @ Shutterstock.com

At the Cato Institute, Peter Van Doren explains why banning natural gas stoves in homes will wind up using more gas. He writes:

In Blue America, electricity is in and natural gas is out. The movement to ban natural gas service in new construction started in Berkeley, California in 2019 and has spread to other localities including New York City. The rationale is that burning natural gas has CO₂ emissions. The unstated implication is that electricity does not.

But the largest single source of electricity in the Unites States is natural gas combustion. In 2021, 38 percent of electricity came from generators powered by natural gas. So, currently the choice is not between electricity and natural gas, but between the use of natural gas directly in the home and use as a fuel at an electric generation facility. Banning natural gas use in the home only makes sense if increasing home electricity use burns less natural gas, and thus emits less CO₂.

Natural gas is used to generate electricity using three technologies. The first makes steam that is used to spin a turbine that drives a generator that makes electricity. The second burns natural gas to spin a turbine directly like a jet engine that then drives a generator. The third, which is a combination of the first two technologies (and is called combined cycle), burns natural gas to spin a turbine directly and also captures the waste heat to make steam and spin another turbine that drives a generator.

Electricity generation is not 100 percent efficient. Thus the energy content of electricity produced through natural gas combustion is less than the energy content of the natural gas used in generation.[1] The heat rate of an electricity generator is the amount of energy used to generate one kilowatt hour (kWh) of electricity. The ratio of the heat content of electricity (3412 British Thermal Units (BTUs) per kWh) to the heat rate of a generator measures the heat lost during the generation process. In 2021 the heat rates in BTUs of natural gas used to generate one kWh of electricity in the U.S. ranged from a high of 11,068 for turbines to 7,580 for combined cycle. Thus, less than a third (3412/11068 or 31 percent) of the natural gas heat content is available from electricity generated from turbines and 45 percent (3412/7580) from combined cycle. And in states such as California, the ironic effect of the use of solar generation is a shift in the composition of natural gas generation away from more efficient combined cycle towards less efficient turbines because of the need to rapidly increase generation at sunset, which is not possible with combined cycle generation.

Any discussion of the CO₂ emissions reduction arising from mandating conversion of end uses to electricity must consider the heat lost during electricity generation. For conventional electric stoves, dryers, hot water heaters, and heating, the heat loss is large. The available heat for use in the home is limited by the heat content of electricity, which is less than half of the heat content of the natural gas used to generate it. Thus, natural gas is used in far greater amounts through electricity generation than would be used if it were burned in residences for those uses.

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