As the electric grid cleans up its act, the grid to get off of will be the natural-gas grid, according to experts studying ways to reduce carbon emissions. But to convince people to cut that cord, electric technologies may have to do everything gas can do—better.
About 68 percent of fossil-fuel use in single-family homes goes to space heating, according to a recent study by the Rocky Mountain Institute. Another 19 percent goes to water heating.
Those tasks can be efficiently performed by electric heat pumps, and RMI found that switching to heat pumps now would already reduce carbon emissions in most of the country.
But there are other tasks performed by gas in the home, and homeowners could save even more emissions—and possibly more money—by finding electric replacements for those, RMI found, and severing their connection to the gas grid entirely.
“One of the benefits we see in making the home all-electric is that the customer can discontinue gas service altogether,” said Mike Henchen, a manager with RMI’s electricity practice. “In one of the states there’s a monthly fixed charge of over $30 for access to the gas system, and that monthly charge goes away entirely when the home becomes fully electrified, and so that’s an additional opportunity for savings.”
That means finding better electric alternatives to the smaller jobs that gas performs, cooking and clothes drying, which produce about 13 percent of a home’s carbon emissions. According to RMI, those alternatives are:
1 Induction Cooking
“If we’re advocating all-electric buildings—especially converting older buildings to become all-electric—we have to address the fact that there are people who enjoy cooking with natural gas.”
Homeowners may be reluctant to convert their heating systems if they have to retain an expensive connection to the gas system anyway for cooking.
“I recognize the preference many people have—the emotional attachment they have—to gas cooking,” he said. “I believe electric induction cooking is a highly capable alternative for people who enjoy the amount of control they have in their heating as they cook on the stove, and it’s equally capable.”
Induction cooking employs an electric coil to create a magnetic field that directly heats the cookware. It delivers heat quickly, unlike a conventional resistance coil, and is said to be 70 percent more efficient than gas or conventional electric, in part because it heats the cookware directly and wastes no energy heating the cooktop itself or the air around it.
According to Henchen, it offers a cook the same nuanced control over heating food that gas does.
“However, there’s a large inertia and a perception that gas cooking is the best option, especially for higher-end customers, and that will be a real barrier to customer adoption, and so increasing interest and excitement around induction cooking would be one strategy,” Henchen said.
Induction cooking is already widely available on the market. The second technology is still in development:
2 Ultrasonic Clothes Drying
Clothes drying “is smaller but not far behind cooking in terms of energy usage,” Henchen said. Nationwide, clothes dryers use 1 percent of the nation’s energy, according to the Department of Energy.
“And again there is a new technology that is an alternative there.”
Ultrasonic dryers use sound waves to vibrate the water out of fabrics, drying them without heat and producing a cool mist. DOE collaborated with General Electric and the University of Florida to develop a prototype ultrasonic dryer.
The prototype dries clothes in about half the time of a conventional dryer, and could save U.S. consumers an estimated $900 million in energy costs over a 10 year period, according to DOE.
RMI found that carbon emissions would drop immediately in much of the country if homeowners electrified now, because in many locations the grid is already carrying clean energy. The emissions could drop to zero, however, when these products are combined with rooftop solar.
