In theory, all of the world's electricity could come from a renewable source, such as solar or wind, if only we had enough batteries to store it. Wind and sunshine are intermittent, so unless the electricity gets used as it's being generated, it goes to waste.
On top of that, the demand for electricity rises and falls. So, if a utility company were going to store extra energy onto batteries, it would also need to be able to pull that energy off to accommodate demand.
Imagine a day when millions of people are driving around in plug-in electric vehicles. Each of those cars has a battery. Each of those car owners has to plug into the grid to charge the battery.
So why not create a system where cars plug into the grid to charge their batteries and where utility companies can use those batteries to store excess electricity or draw out electricity when demand on the grid is high?
And then take it one step farther: generate a large percentage of the electricity using renewable sources. Now you'e reducing emissions at the power generation facility and eliminating them at the car.
This kind of large-scale, rechargeable battery network is called vehicle-to-grid technology, or V2G.
V2G is still a decade or so away, but quite a few people are working away on it from a bunch of different angles. We picked out 10 electric car projects that are contributing to the vehicle-to-grid concept.
10. Better Place
Launched: October 2007
Vehicle: Renault-Nissan
Where: California, Israel, Denmark, Australia, California, Hawaii and Canada
What: Not exactly a vehicle-to-grid project, Better Place is a company with an electric car concept that takes inspiration from the mobile phone network. With a mobile phone plan, you get a phone and a choice of buying different quantities of minutes. Better Place's idea is to sell cars with different amounts of electricity. Drive a lot? Buy a lot of electricity. Drive just a little? Buy less. The company plans to have a network of charging stations and battery switch stations (in the event a subscriber doesn't have time for a charge) up and running in a partner country by 2010. And although their business plan does not include a vehicle-to-grid component in the near future, Better Place's partnerships with car and utility companies and their focus on battery switching will drive innovations in three of the major areas critical to V2G.
9. Austin Energy V2G Pilot
Launched: January 2008
Vehicle: Toyota Prius Plug-in Hybrid
Where: Texas
What: The Austin, Tex-based utility is field-testing two plug-in hybrid electric that have a communication module developed by Seattle-based V2Green,
recently acquired by Gridpoint, in Arlington, Va. The module uses a
wireless connection to provide a two-way communication between a
utility company and the car to manage the flow of
electricity. During periods of peak demand, charging can be delayed or slowed down to lessen the impact. And during period of low-demand, the cars can charge. Such capabilities could encourage utility companies to seek out more sources of renewable energy.
"Plug-in hybrid or electric vehicles can certainly enable more wind," said Larry Alford, manager of distributed generation. "Wind blows mostly at night here in Texas so we can charge the electric vehicles at night."
8. Plug-in Vehicle Trial
Launched: October 2008
Vehicle: Toyota Prius Plug-in Hybrid
Where: North Carolina and Florida
What: The Advanced Transportation Energy Center at North Carolina State University in Raleigh, N.C., has partnered with Advanced Energy,
a nonprofit agency, Duke Energy and Progress Energy to test the impact
of plug-in vehicles on the grid. Each of twelve hybrid-electric Toyota
Priuses in the trial has the V2Green module
Researchers understand that before V2G can be released, certain
intermediary goals have to be reached. For that reason, they are
addressing the issue in three stages. The first is smart charging,
where a vehicle's charge rate is controlled remotely based on the
driver's need and grid conditions. Next, is vehicle-to-building, where
a remote-controlled charger would be able to feed power back to the
home to provide back up power. And, finally, vehicle-to-grid.
7. Seattle's Plug-In Hybrid Demonstration Project
Launched: May 2008
Vehicle: Toyota Prius Plug-in Hybrid
Where: Washington
What: The utility company Seattle City Light is field-testing 13 plug-in hybrids and their potential impact on the power grid. According to Scott Thomsen, strategic advisor, Seattle City Light is one of the country's largest carbon-neutral utility companies. As a result, they have a lot of potential for a zero-emission vehicle-to-grid system. Like the cars in the Austin project, the Seattle cars are also equipped with V2Green's onboard communication. Performance data gathered is sent via a wireless network to the Idaho National Laboratory, where it is collected and analyzed. The cars are not equipped to deliver electricity back to the grid.
6. SMART@CAR Launched: October, 2008
Cars: Toyota Plug-in Hybrid Prius
Where: Ohio
What: SMART@CAR is a project of the Center for Automotive Research at The Ohio State University. The basic idea is to bring businesses and organizations together to research sustainable vehicles. The focus is on electric vehicles and plug-in hybrid electric vehicles . Studying the way these vehicles interact with the electrical grid, including the V2G scenario, is one aspect of the research. The idea is to analyze residential, commercial and industrial use, examining everything from cost to how the cars will affect the grid. SMART@CAR is also looking at scenarios in which plug-in hybrids provide power directly to buildings. Another of SMART@CAR's projects focuses on the communications and technology standards that will be necessary to bring V2G to market. The group plans to have 10 to 20 PHEVs on the roads in Columbus, OH, by the end of the year.
5. e-mobility
Launched: September, 2008
Cars: Mercedes Benz and Smart
Where: Germany and Italy
What: The e-mobility project is a partnership between Stuttgart, Germany-based Daimler AG and utility companies in Germany (RWE AG) and Italy (Enel) to advance technology in electric cars and power grids that will one day accommodate vehicle-to-grid capabilities. Currently two hundred electric cars from Mercedes-Benz and Smart are being deployed in Berlin, Rome, Milan and Pisa. And the respective utility companies are working to install a network of 900 charging points at homes, businesses, parking areas and shopping centers. An in-car communication system will help manage the exchange of data between the car and the utility company and also manage payment. Daimler has also partnered with the Karlsruhe Institute of Technology to establish the e-drive project house, which will study power electronics, control and feedback control systems, and also electric storage units and electrical machines as they relate to V2G.
4. Southern California Edison
Launched: On-going
Cars: Toyota Rav 4
Where: Southern California
What: Southern California Edison, headquartered in Rosemead, Calif., is one of the country's largest utility companies, servicing more than 13 million people in 180 cities. On top of that, it buys between one-eighth and one-sixteenth of the nation's wind and 80 percent of its solar energy. So it's no surprise that the utility is investigating grid-connecting electric-drive technologies. To that end, they have an Electric Vehicle Technical Center, which allows them to evaluate electric vehicle performance and vehicle and fleet operation. In fact, the utility company has 300 electric-powered vehicles in service now. But they are not vehicle-to-grid.
"We've got significant hurdles to get over before we get to that point," said Edward Kjaer, director of electric transportation.
We need two things before that can, said Kjaer, mature, reliable batteries and a smarter grid. To that end, Southern California Edison is working to make improvements in those areas. By 2012, for example, 5 million of its customers will have a smart meter in their homes. And in the company's Garage of the Future, researchers are looking at vehicle-to-home, where electricity and transportation can merge to create energy storage at home.
3. Google RechargeIT
Launched: June 2007
Cars: Toyota Prius and Ford Escape Hybrids and Plug-in Hybrids
Where: California
What: Google.org, the philanthropic arm of Google, is testing and comparing the performance of 17 vehicles -- a mix of hybrid and plug-in electric hybrid engines –- to accelerate the commercialization of plug-in vehicles. In true Google form, the company puts the collected data online for all to view. RechargeIT is a part of the Google's larger effort to reduce greenhouse gas emissions. At the same time that they're investigating the use of plug-in vehicles, they're also exploring breakthrough technologies that produce electricity from renewable energy sources. In just a few years, the RE<C (renewable energy cheaper than coal) initiative could be producing one gigawatt of renewable energy. RE<C along with RechargeIT could have us all plugging into a green grid in no time.
2. SmartGridCity
Launched: October 2008
Cars: Toyota Prius and For Escape Plug-in Hybrids
Where: Colorado
What: Xcel Energy, headquarted in Minneapolis, Minn. wants to convert the entire city of Boulder, Colo., to a smart grid system. The process involves upgrading everything from home energy meters to electrical substations. In addition, the company will need to make the power grid more stable, optimize electricity distribution and add more renewable energy sources to the city's electricity supply. Of the four Toyota Prius and six Ford Escape PHEVs in the fleet, at least three of the vehicles has a special inverter that allows the utility company to pull power from the battery, during periods of peak demand. In phase two of the project, 60 additional hybrid-electric plug-in vehicles will be added with a long-term goal of adding 500 vehicles.
1. The Center for Carbon-free Power Integration
Launched: September 2008
Cars: Toyota Scion XBs
Where: Delaware
What: The Center for Carbon-Free Power Integration launched in 2008, but Willet Kempton, the researcher at the heart of this collaboration, has been involved in V2G research for more than 10 years. This past January, his hard work started making its way into the real world. Newark, Del., became the first city to field test all-electric cars and technology that actually feeds power back into the grid. In fact, Kempton's program is one of the few projects out there with the capability to do so. The ability lies in the propulsion system, which can take the AC current of electricity from the power outlet, convert it to DC to be stored on the battery, convert it to AC to drive the wheels and do the whole thing in reverse to put the electricity back onto the grid.
Why doesn't every electric car do that? "It adds cycles to the battery, which shortens its life," said John Clark, former CEO of V2Green and now a member of Gridpoint's corporate development group.
Clark, like many V2G proponents, say that the proof lies in the battery.
But Kempton's project goes forward. In its first phase, the it's using an all-electric car and two charging stations that can feed electricity back into the city's grid. By the end of 2009, the project should expand to six vehicles.
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