The home of the not-too-distant future may be connected to the grid, but power is expected to flow in two directions. Energy systems, including solar panels, wind turbines and fuel cells (with battery backup), will make electricity at home, perhaps even more than the house needs. And the car in the garage will be tapped as another source of energy storage, ready to send electricity anywhere it’s needed, including to the local utility to help manage loads.
This vision is being pursued most dramatically in Japan, where such companies as Nissan, Toyota, Panasonic and Sharp are presenting startlingly original concepts for how our at-home lives might evolve. Some are going further and planning to enter the marketplace. Meanwhile, American companies such as General Electric [GE is the sponsor of Txchnologist.com—Ed.] are pursuing parallel tracks.
Smart appliances and zero emissions
Panasonic may be known for 3-D televisions in the U.S., but its green side is very apparent on the Japanese market. There, it sells smart air conditioners that can scan the room they’re in, count the number of people present and register if they’re relaxing or working out, then adjust its cool air output accordingly. A company refrigerator learns its owners’ patterns and goes into low-power mode during quiet times.
I was able to tour the Panasonic Eco Ideas House in Tokyo, which achieves zero CO2 emissions by generating electricity with a rooftop five-kilowatt solar panel and a fuel cell running on liquefied natural gas. A five-kilowatt-hour lithium-ion battery pack stores energy during the day from the solar panel, for use at night.
Slats in the walls carry in air from beneath the house that is warmer in the winter and cooler in the summer. It’s an affordable answer to home geothermal air-conditioning systems. Appliances, from the refrigerator to the tea maker (it’s Japan, after all), are insulated with a thin vacuum layer to improve their efficiency. That’s not available at Home Depot yet, but the LED lighting through the Eco Ideas House is—and it consumes a sixth of the energy of incandescents.
The house’s fuel cell produces electricity from the hydrogen-rich natural gas supply—a concept that’s increasingly practical in the U.S., where the price of natural gas is the lowest in the world. GE, a fuel-cell pioneer that developed systems for the Apollo space missions, explored a home hydrogen unit with partner Plug Power that would have launched in 2001, but its electricity production turned out not to be competitive with that produced by traditional utilities at that time. Today, it might work, and in Japan home-based fuel cells are subsidized with a half-price government subsidy, which brings their cost down to approximately $11,000. More than 5,000 are in homes now.
Government support helps. Korea is also emphasizing zero-emission energy from fuel cells, and has the world’s largest hydrogen installations already in place. Capital city Seoul plans to replace a nuclear power plant with 230 megawatts of stationary power.
Cars give back to the grid
Back at the Eco Ideas House, an AC/DC power manager handles the home’s diverse energy sources. During my visit, there was an early version of the Toyota Prius plug-in hybrid in the garage, charging on home-brewed electricity. But cars can do more. Nissan is launching its “Leaf to Home” system in Japanese showrooms starting this month. It’s a box that looks something like a central air conditioner, but it’s a fast car charger with two-way power flow.
The new unit can charge a Leaf in four hours, but it also connects the car’s quick-charge port to the grid, using the 24 kilowatt-hours of electricity in the battery pack to provide backup power to the home. Nissan says Leaf to Home can keep the average Japanese household supplied for two days, but Americans have larger houses and use a lot more power, so results would be less here. A standard Prius can also be used for this purpose and might actually last longer—despite a much smaller pack—because the gas engine acts as a generator to keep the batteries charged.
The system costs an affordable $4,800 with government subsidies, but another $3,800 for installation. Nissan and partner Nichicon hope to sell 10,000 units in the first fiscal year.
Toyota is a partner (with Hitachi, Japan Wind and Panasonic) in Japan’s Rokkasho Smart Grid Village that was launched two years ago with the hope of commercializing the systems it’s testing. The six homes, each with a plug-in Prius, has echoes of Disney’s EPCOT. The homes are interconnected and share power. At the heart of the system is Toyota’s “Smart Center,” which collates data from the household-linked electric vehicle charger to coordinate that large load with the home’s own needs. One way it does that is by controlling when the energy-efficient “EcoCute” water heater runs. It’s smart-phone enabled, so homeowners can always check on their car’s state of charge and power draw.
Major electronics company Sharp is also into eco-houses, and built an energy showcase in Osaka, Japan, in 2011. Thanks to a total makeover involving appliances, lighting and insulation, it’s total energy consumption is about two-thirds that of an average home, with an approximately 30 percent electricity savings. A system similar to Toyota’s Smart Center monitors charging for the Mitsubishi i electric car that’s along for the ride. As in most smart-grid applications, the homeowner gets instant information on each appliance’s power consumption. When you shut off lights, you’ll see the difference on your phone or computer. Just having that awareness is likely to lead to 15 percent energy savings, says Sharp.
The Osaka house is conventional, but the “Stairs House” in Shimane Prefecture is anything but. In place of a roof is a set of wide stairs designed for outdoor lounging, as the house uses passive heating and cooling to maintain a low energy profile.
Finally, Honda is using solar power to generate hydrogen that can refuel the company’s fuel-cell cars, such as the FCX Clarity, that the company plans to commercialize as early as 2015. The home-based station is designed to provide enough hydrogen for 10,000 miles of annual commuting. The system makes hydrogen during the day while the sun is shining and refills the car overnight. No battery backup is needed.
GE has already commercialized a system that uses solar power to recharge electric vehicles. I visited the company’s Plainville, CT., installation, which has six charging bays and the capacity to plug in as many as 13 electric vehicles (EV) per day. GE is buying at least 12,000 Chevrolet Volts, and I saw five of them charging at once in Plainville. But GE’s solar EV chargers can be scaled down or up for customers.
GE, which makes the WattStation EV charger, is partnering with Urban Green Energy to hook EV chargers to the futuristic Sanya Skypump, an innovative streetlamp with built-in off-grid solar and wind-turbine power generation. The partnership has municipal customers in mind, but GE also envisions a home-based unit that incorporates the wind turbine.
These concepts may sound like science fiction, but the great thing is that they’re up and working now. And some are either on the market or are about to be.
Top image: Honda uses solar to produce hydrogen for its fuel cell cars. Courtesy Honda.