It's common to question exactly how your home's electricity use relates to greenhouse gas (GHG) emissions. In contrast to the straightforward combustion of fossil fuels that occurs when we drive, we don't always recognize the emissions that enter the atmosphere due to our everyday electricity use.
However, the environmental impact of energy-efficient practices at one's home can be significant: the U.S. domestic sector produced approximately 19% of national GHG emissions in 2016. Of that, 69% of residential emissions resulted from electricity use, with direct fossil fuel combustion for home heating making up the other 32%. Considering that such a large percentage of household GHG emissions are tied to electricity usage, it becomes clear that home energy efficiency measures can result in significant reductions in GHG emissions.
In most cases, the money you save from implementing energy-efficient measures translates directly into fewer GHG emissions due to the nature of electricity generation. For instance, electricity for lighting makes up around 20% of the average electricity bill. If you replace your incandescent lightbulbs with Energy Star-qualified CFL bulbs, you can reduce the amount of electricity you use to light your home by 75%. If one incandescent lightbulb were replaced with a CFL bulb in every American home, it would save enough electricity in a year to power 3 million homes, reducing annual emissions by taking 800,000 cars off the road. CFL bulbs also offer environmental benefits in reducing mercury emissions, combatting a growing concern in freshwater and marine habitats.
Most electricity generation in the United States today occurs in thermal power plants, which burn fossil fuels like coal and natural gas, biofuels, or nuclear energy to heat water and produce steam. The steam spins a turbine to produce electricity, which feeds into the utility grid. When we burn fossil fuels for electricity, we also produce greenhouse gas emissions that contribute to climate change.
Most US electricity generated in utility-scale facilities is from coal or natural gas. Another chunk comes from nuclear power plants. All of that electricity generation produces around a third of US energy-related carbon dioxide emissions – the single most significant contributor to GHG emissions in the country. As you improve your home's energy efficiency, you need less electricity and thus rely less on carbon-intensive power plants. This reduces your home's demand from the plant, which benefits the environment by reducing carbon dioxide emissions.
Fortunately for you, there are local, state, and federal energy incentive programs to help you become an energy-savvy consumer. The best-known program is the ENERGY STAR program, founded in 1992 by the U.S. Environmental Protection Agency (EPA) to promote energy-efficient consumer products and combat climate change. The ENERGY STAR certification for energy efficiency now also includes homes, buildings, and productive facilities.
ENERGY STAR has provided energy bill savings and emissions reductions to homeowners and businesses on an unprecedented scale. It's the most successful voluntary energy conservation program in history regarding economic benefits and reduced emissions.
In 2014, the ENERGY STAR program saved consumers $31 billion on energy bills. That is equivalent to 5% of total U.S. electricity demand and the annual GHG emissions of 38 million homes. For the individual homeowner, this translates to an average savings of $4.50 per dollar on energy spending through ENERGY STAR.
Reducing your energy use can lower the amount of electricity your utility needs to produce, which you can effectively reduce your greenhouse gas emissions (and your carbon footprint) with energy efficiency measures. In addition to the direct financial and environmental benefits of implementing energy efficiency measures, coupling energy efficiency with other "green" practices can offer even further advantages.
For example, savings on your electricity bill can be diverted into charging electric vehicles, contributing to household savings on fuel and electricity expenditures. Solar panel owners can also generate higher surpluses of net metering credits, cutting annual energy costs even further. Due to the variety of benefits, implementing energy-efficient practices at home should be and has been a growing priority among energy-savvy homeowners and renters alike.