For many years, energy agencies have alerted Americans to the importance of energy efficiency. A variety of tags and certifications, backed by financial incentives, encourage us to understand our equipment buying options. We know that it makes sense to spend a little more on a product so that we can save money and energy throughout its useful life.
These efforts continue to reduce per capita energy use for both natural gas and electric customers. And the more energy we save, the lower our impact on the environment.
The Whole Story
But focusing on product efficiency only reveals half the story. To get the whole picture, it’s important to look at what’s called the full fuel cycle. That means understanding how much energy is retained – or lost – from the energy’s source until its final use in your water heater, oven or home heating system.
And with the full fuel cycle in mind, direct use of natural gas comes out a winner in the energy efficiency race. For instance, by the time you turn on your electric appliance, up to 68 percent of the energy value from the original fuel has been lost. So the full fuel cycle efficiency is about 32 percent. The full fuel cycle efficiency of a natural gas appliance is about 92 percent – a substantial difference.
- Even with advances in renewable power, most electricity in the U.S. is generated by either coal or natural gas.
- We lose some of the energy benefits of those fuels as they are transported to the power plant.
- The major energy loss occurs during generation itself when potentially useful energy is lost in the form of heat as the fuel is burned to crank an engine or turn a turbine.
- Finally, we lose more energy over the electric transmission lines. So for every 100 MMBtu of fuel that leaves the mine or well, only 32 MMBtu is left to power our electrical appliances.
These fuel choices have important environmental implications. On average, the house fueled by natural gas is responsible for about one-third fewer greenhouse gas emissions than a comparable all-electric home (American Gas Association, Dispatching Direct Use: Achieving GHG Reductions with Natural Gas in Homes and Businesses, Nov 2015). Furthermore, the more fuel we waste, the more we need to produce and transport – processes that also affect the environment.
We are approaching a future when a combination of wind, solar, wave energy and usable storage will reduce our reliance on fossil fuels. Until then, one of the most effective ways we have to save energy and reduce carbon emissions today is to use natural gas directly in our homes, businesses, and vehicles wherever gas is available. We have the ability to maximize these benefits using today’s technologies.
Graphic courtesy of American Gas Association