As appliances and electric meters get smarter, researchers are teaching them to talk to each other in ways that could help you use electricity more efficiently
In the future, you’ll be able to talk to your electric outlet and people won’t think you’re crazy.
During the previous century, the electric utility system operated in a relatively straightforward way. Electricity was generated at a power plant, flowed through transmission lines, then through distribution lines to the customer.
The system worked strictly one-way. It was as if telephones were only good for hearing announcements, with no way to talk back to the person at the other end.
Electric meters only measured the amount of current flowing through, and required a human being to read and report the numbers once a month.
A few years ago, some utilities began testing a new kind of electric meter. These meters could send information back through the power lines to the local utility each day. Because the new meters could talk back to the utility and report their own readings and locations, people called them “smart” meters.
Smart meters were the first step toward a new power system for the new century.
A second step involves innovations in appliances, thermostats, and other equipment, making some of them “smart,” too.
Today, you can buy programmable thermostats that make it possible to give your furnace or air conditioner instructions about what temperature to maintain during the week and over the weekend, whether you’re at home or not. You can set your VCR to record a TV movie while you’re asleep. Many other appliances have sensors and special features that allow them to function independently based on human instructions.
But are these appliances really smart?
Not as smart as they could be.
Right now, meters and appliances live in separate worlds. They cannot communicate with each other.
But scientists and engineers are trying to figure out ways for appliances and equipment to communicate in a two-way fashion with the electric meter and the electric utility company. This new system would still allow humans to make choices, but would also include some automated features.
Developers call it a “smart power delivery system.”
Adding information to electricity
So far, we’ve seen two ingredients for this new power system, smart meters and smart appliances. The key to success involves adding a third ingredient: information about the price of electricity.
Most people don’t realize that electric utilities have to pay different prices for the electricity they buy to send to customers depending on circumstances like time of day.
If people could know more about the true cost of electricity at a certain time, whether it’s higher or lower than usual, they might shift their electricity use to a different time to save money—both for the electric utility and for themselves. Spreading electricity use out more evenly around the clock could lead to big savings at power plants and delay expensive new construction.
So the third step to achieving the smart power delivery system is actually a very smart meter combined with very smart appliances and equipment that use price information to work together. The meter would be able to communicate the price of the electricity flowing through it, and the other devices could then use that information to carry out money- and energy-saving instructions from humans.
Taking full advantage of those money- and energy-saving instructions would require a complicated fourth step that goes beyond the technical skills of the scientists. That would involve working with government regulators to design a new system of electric rates that would allow appliances to take advantage of the most efficient times to use electricity.
But that’s a story for another column. First things first.
How information saves money
To see how very smart meters and very smart appliances work together, you have to understand some of the words frequently used in the electric utility industry. Although the words are common enough, many have special meanings when they’re used to talk about electricity.
Let’s start at your home. For most residential electric consumers, the rate (most people call it the price) of the electricity you use remains constant over long periods of time.
The rate is what you, the consumer, pay per kilowatt-hour for the electricity you use. (Depending on local circumstances, there may be some other items on your bill as well.)
Your electric meter measures how much electricity you use. How much electricity you use during the billing period, multiplied by the rate, determines what you pay each month. Your basic rate stays the same for many months, but your use changes from month to month.
Now let’s go all the way back to the power plant. When electricity is being generated and sent out through the transmission and distribution lines, power plant operators must match the amount of electricity being generated as closely as possible to the amount of electricity people want at that moment. That’s called demand. The amount of power needed to meet that demand is called the load.
At different times of day and at different times of the year, the demand for electricity increases or decreases. Peak demand is when people want the most electricity.
Here’s where money comes back into the discussion. It is often much more expensive than normal for the utility company to generate enough electricity to meet the needs of electricity users during peak demand times. But most residential customers pay a rate that is based on the average of the utility company’s costs over a long time period as it generates that electricity and delivers it to you.
In some parts of the country, large industrial customers and some residential customers have a tiered rate structure. In one tier, the rate is called the peak demand rate (the higher rate); in another tier, the rate is called the off-peak demand rate (the lower rate). These different rates reflect the differences in what it costs the utility to provide electricity during these different times.
Turning ideas into reality
What if any electric customer could have a very smart meter that knew what the higher price of electricity would be at 4:00 this afternoon during peak demand, and could also predict the lower price tonight at 10:00 during off-peak demand?
What if your appliances could have that same information and turn themselves on or off to save you money?
Researchers at the Living Lab for Energy Efficiency in Knoxville, Tennessee, call this “getting prices to devices.” Program Manager Brian Fortenbery and other electrical engineers there have racks of equipment set up to test how appliances and meters can talk to each other.
“Right now, a lot of different manufacturers are trying different things and we’re testing some of those here in our labs,” Fortenbery says. Some devices being tested are intended for home use and others for commercial use.
As an example, you could instruct your air conditioner to stop running for an hour anytime the price of electricity reached a certain limit you set. You could also tell your water heater to maintain a lower temperature during the higher rate portions of the day, then go back to the warmer temperature when electricity is cheaper.
Different manufacturers are trying different approaches, often with unique technology. Some patented items are proprietary, which means only one company can use it; all components would have to use the same manufacturer’s system. Another problem with everybody coming up with their own approach is that the individual pieces might not be able to communicate or react with each other.
“We think there will eventually be a gateway for all this information to go through,” Fortenbery says, “but we don’t know yet what that gateway will be.” It might be something that’s part of the next kind of electric meter, or it might involve adding Internet communications to all parts of the system.
Instead of each company coming up with something different, independent engineers working in many states hope to find a system that works well in many situations, then make that available to everyone else. That’s called an “open source.” If manufacturers can agree on standards and working methods, then the new smart power delivery system could have interchangeable components, rather like the way computer systems and their extras are now almost completely compatible with “plug and play” built in as standard.
Research at the Knoxville lab is helping determine what works in some life-like situations—and how to fix any disturbances that these new devices might accidentally create in our familiar, reliable system.
“A lot depends on what changes occur in the marketplace regarding electricity prices,” Fortenbery says. “Within the next five to 10 years these new devices could be commonplace.”
Next month: The role of renewable energy