When an especially high electricity bill arrives in the mail, it's enough to just adjust the dials on the thermostat and the refrigerator, right? Maybe not. It turns out it's the tangle of electronics near the television that's the fastest growing segment of energy use.

Most of the electronics, including laptops, smart phones and tablets, require an Internet connection. Our networking equipment—primarily modems, routers and cable/DSL gateways—which a majority of American homes now have, are also an energy drain. A new report by the Natural Resources Defense Council (NRDC) and Ecova [PDF] found that residential networking costs Americans more than US $1 billion a year, but could be cut by a third using already existing technology. The cumulative energy use, about 8.3 billion kilowatt-hours of electricity, is the equivalent of three large power plants.

“Small network devices suck roughly the same amount of energy around the clock, whether or not you are sending or receiving any data,” said Noah Horowitz, a NRDC senior scientist, in a statement. “But there are steps that manufacturers can—and should—take to make sure these devices are no longer energy vampires.”

Two existing industry standards can help increase the energy efficiency for modems and routers: IEEE 802.3az Energy Efficient Ethernet (EEE) for Ethernet ports, and IEEE 802.11e, which governs automatic power save delivery (APSD).

The standards allow the devices to enter a low-power sleep state when no data is being moved around the network but then quickly wake them up and send data if necessary—quickly enough that consumers shouldn't notice the difference. Without such as sleep mode, a modem's annual energy use is similar to that of a 32-inch flat screen TV. 

home networking efficiency

The U.S. Environmental Protection Agency is working on an Energy Star specification, but it does not require modems and routers to meet the EEE standard, according to the NRDC report. The EEE standard could be also used for increased efficiency in computer, printers and other connected devices.  

Ecova and NRDC found that networking devices that were labeled as energy efficient did draw the least power. In nearly all cases, it is more efficient to use a gateway that combines modem and routing functionality rather than to have separate devices.

A small but growing piece of the energy consumption from home networking is Optical Network Terminals (ONTs), which are usually attached to the outside of the home to translate optical signals into electronic signals for customers with high-speed fiber optic service. There are about six million ONTs compared to about 40 million modems in the United States.

The difference in efficiency across all the devices tested was related to variation in capability (such as a device that can send 1 gigabit per second, compared to 100 megabit per second). But when the study normalized for feature differences, it found that the top 25 percent of devices used one-third less energy. Some of the devices simply always operated at a lower power, while others went into sleep mode when network traffic was low. If all of the residential networking equipment were replaced with more efficient models, the savings would be $330 million annually.

Thus the efficiency goals are not a pie-in-the-sky dream. Even though the EEE standard was supported by only two of the 23 routers tested in the study, manufacturers told NRDC it will become pervasive in the next few years. The first generation of EEE devices is expected to save between 5 and 20 percent of system power, but next-generation designs could save up to 80 percent. Such gains in efficiency would offset any increases that will come from faster data transfer rates. NRDC recommends that the government make home networking standards mandatory.

Home networking, however, is just one part of the puzzle. There are also moves afoot for more efficient Wi-Fi, and the U.S. Department of Energy is currently hashing out the first mandatory energy efficiency standards for cable set-top boxes and televisions. On an even larger scale, there is an international effort to make all information and communication technology networks more efficient by a factor of 1000 compared to 2010 levels.


Images: art12321/iStockphoto, NRDC

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This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

The number of charging stations in Utrecht has risen sharply over the past decade.

“People are buying more and more electric cars,” says Eerenberg, the alderman. City officials noticed a surge in such purchases in recent years, only to hear complaints from Utrechters that they then had to go through a long application process to have a charger installed where they could use it. Eerenberg, a computer scientist by training, is still working to unwind these knots. He realizes that the city has to go faster if it is to meet the Dutch government’s mandate for all new cars to be zero-emission in eight years.

The amount of energy being used to charge EVs in Utrecht has skyrocketed in recent years.

Although similar mandates to put more zero-emission vehicles on the road in New York and California failed in the past, the pressure for vehicle electrification is higher now. And Utrecht city officials want to get ahead of demand for greener transportation solutions. This is a city that just built a central underground parking garage for 12,500 bicycles and spent years digging up a freeway that ran through the center of town, replacing it with a canal in the name of clean air and healthy urban living.

A driving force in shaping these changes is Matthijs Kok, the city’s energy-transition manager. He took me on a tour—by bicycle, naturally—of Utrecht’s new green infrastructure, pointing to some recent additions, like a stationary battery designed to store solar energy from the many panels slated for installation at a local public housing development.

This map of Utrecht shows the city’s EV-charging infrastructure. Orange dots are the locations of existing charging stations; red dots denote charging stations under development. Green dots are possible sites for future charging stations.

“This is why we all do it,” Kok says, stepping away from his propped-up bike and pointing to a brick shed that houses a 400-kilowatt transformer. These transformers are the final link in the chain that runs from the power-generating plant to high-tension wires to medium-voltage substations to low-voltage transformers to people’s kitchens.

There are thousands of these transformers in a typical city. But if too many electric cars in one area need charging, transformers like this can easily become overloaded. Bidirectional charging promises to ease such problems.

Kok works with others in city government to compile data and create maps, dividing the city into neighborhoods. Each one is annotated with data on population, types of households, vehicles, and other data. Together with a contracted data-science group, and with input from ordinary citizens, they developed a policy-driven algorithm to help pick the best locations for new charging stations. The city also included incentives for deploying bidirectional chargers in its 10-year contracts with vehicle charge-station operators. So, in these chargers went.

Experts expect bidirectional charging to work particularly well for vehicles that are part of a fleet whose movements are predictable. In such cases, an operator can readily program when to charge and discharge a car’s battery.

We Drive Solar earns credit by sending battery power from its fleet to the local grid during times of peak demand and charges the cars’ batteries back up during off-peak hours. If it does that well, drivers don’t lose any range they might need when they pick up their cars. And these daily energy trades help to keep prices down for subscribers.

Encouraging car-sharing schemes like We Drive Solar appeals to Utrecht officials because of the struggle with parking—a chronic ailment common to most growing cities. A huge construction site near the Utrecht city center will soon add 10,000 new apartments. Additional housing is welcome, but 10,000 additional cars would not be. Planners want the ratio to be more like one car for every 10 households—and the amount of dedicated public parking in the new neighborhoods will reflect that goal.

This photograph shows four parked vehicles, each with the words \u201cWe Drive Solar\u201d prominently displayed, and each plugged into a charge point.Some of the cars available from We Drive Solar, including these Hyundai Ioniq 5s, are capable of bidirectional charging.We Drive Solar

Projections for the large-scale electrification of transportation in Europe are daunting. According to a Eurelectric/Deloitte report, there could be 50 million to 70 million electric vehicles in Europe by 2030, requiring several million new charging points, bidirectional or otherwise. Power-distribution grids will need hundreds of billions of euros in investment to support these new stations.

The morning before Eerenberg sat down with me at city hall to explain Utrecht’s charge-station planning algorithm, war broke out in Ukraine. Energy prices now strain many households to the breaking point. Gasoline has reached $6 a gallon (if not more) in some places in the United States. In Germany in mid-June, the driver of a modest VW Golf had to pay about €100 (more than $100) to fill the tank. In the U.K., utility bills shot up on average by more than 50 percent on the first of April.

The war upended energy policies across the European continent and around the world, focusing people’s attention on energy independence and security, and reinforcing policies already in motion, such as the creation of emission-free zones in city centers and the replacement of conventional cars with electric ones. How best to bring about the needed changes is often unclear, but modeling can help.

Nico Brinkel, who is working on his doctorate in Wilfried van Sark’s photovoltaics-integration lab at Utrecht University, focuses his models at the local level. In his calculations, he figures that, in and around Utrecht, low-voltage grid reinforcements cost about €17,000 per transformer and about €100,000 per kilometer of replacement cable. “If we are moving to a fully electrical system, if we’re adding a lot of wind energy, a lot of solar, a lot of heat pumps, a lot of electric vehicles…,” his voice trails off. “Our grid was not designed for this.”

But the electrical infrastructure will have to keep up. One of Brinkel’s studies suggests that if a good fraction of the EV chargers are bidirectional, such costs could be spread out in a more manageable way. “Ideally, I think it would be best if all of the new chargers were bidirectional,” he says. “The extra costs are not that high.”

Berg doesn’t need convincing. He has been thinking about what bidirectional charging offers the whole of the Netherlands. He figures that 1.5 million EVs with bidirectional capabilities—in a country of 8 million cars—would balance the national grid. “You could do anything with renewable energy then,” he says.

Seeing that his country is starting with just hundreds of cars capable of bidirectional charging, 1.5 million is a big number. But one day, the Dutch might actually get there.

This article appears in the August 2022 print issue as “A Road Test for Vehicle-to-Grid Tech.”

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