-¿Cómo funciona su coche V2G?
-Es un automóvil como todos que funciona a través de la energía eléctrica y capaz de tomar corriente cuando no está en funcionamiento: almacena electricidad suficiente para alimentar varias casas durante unos 30 minutos.
-¿Cuántas casas abastece?
-La energía almacenada por la batería del vehículo puede cubrir la demanda de siete u ocho bloques de viviendas durante alrededor de media hora. A finales de este año esperamos poder contar con seis vehículos para demostrar la viabilidad de conectarse conjuntamente a la red.
-¿Cuánto cuesta el enchufe?
-El coste aproximado por tener instalado el enchufe grande es de unos 600 dólares. Nuestros planes actuales pasan por agregar la tecnología V2G al autobús con célula de combustible de hidrógeno que utilizamos en los desplazamientos de la universidad de Delaware, donde doy clases.
-¿Falta concienciación para apostar definitivamente por el coche eléctrico a nivel social?
-Yo creo que hay demanda ya, ahora mismo, no sé en qué porcentaje, lo que pasa es que no hay coches y los que hay, son carísimos. De nuestro modelo sólo tenemos uno, seamos claros, pero nosotros no desarrollamos coches, hacemos prototipos para probar nuestras investigaciones. De todos modos, hemos avanzadas conversaciones con un fabricante interesado en fabricar ya en breve en torno a 300 al año.
-¿Es una utopía soñar hoy por hoy con una implantación masiva del coche eléctrico como sustituto para el vehículo de gasolina?
-No es un sueño, es una necesidad porque no hay petróleo suficiente para todo el mundo de forma ilimitada. Además, la electricidad es una forma de energía más ecológica y eficiente porque la mayoría de la energía llega mediante el movimiento del vehículo, no por la combustión como las gasolinas.
-¿Pero es realista pensar que se va a sustituir el coche de gasolina?
-Yo manejo uno ya, el prototipo que hemos desarrollado, el V2G (vehículo a red). Usa la capacidad que tienen las baterías de los coches para almacenar energía y devolverla y suministrársela a la propia red cuando la necesite bien sea por contratiempos, apagones… Muchos coches en un país entero suministrando a la red significarían una capacidad generadora nada desdeñable. porque nuestro coche permite el flujo de electricidad desde la batería del automóvil hacia las líneas de distribución eléctrica y viceversa.
-¿Es esa la principal novedad que introduce su prototipo?
-Es que es algo más que un vehículo, es una idea, un concepto de futuro. El coche alimentando a la propia red suministradora, en la línea de la energía solar. La tecnología funcionará a gran escala ya que por término medio el 95% de todos los automóviles están estacionados en un momento dado; el uso diario de un automóvil en países como EE UU es de una hora al día como promedio.
-¿Se trataría de aprovechar ese tiempo muerto del coche?
-Un automóvil de gasolina estacionado no realiza ninguna tarea. Si existe una batería que almacena electricidad y un enchufe capaz de alternar rápidamente entre la emisión o la recepción de energía, entonces el automóvil estará trabajando incluso cuando esté aparcado, y resultará más valioso que un automóvil de gasolina convencional. Yo tengo ya un gran enchufe en casa y otro en la universidad. Es un enchufe de 240 voltios que permite la recarga completa de la batería, con autonomía para unos 200 kilómetros, en sólo dos horas. Pero un enchufe más pequeño de 110 voltios, el estándar en ciertos países, también proporciona una carga completa, aunque después de funcionar durante unas 12 horas.
-¿Cuál es el principal problema al que se enfrenta el coche eléctrico para su implantación?
-El principal que las grandes compañías y grandes fabricantes de coches no están todavía acostumbrados y preparados para fabricarlos a gran escala. El segundo es la pila, la batería, que no tiene duración suficiente para hacer funcionar el coche. Hablo de su longevidad, de su vida efectiva, de su durabilidad. Pero eso es algo que se puede resolver investigando. Sólo es cuestión de tiempo su desarrollo.
-¿Considera crucial el apoyo de las administraciones con dinero público para lanzar el coche eléctrico como alternativa factible?
-Sin duda. En Estados Unidos se trabaja ya con el cálculo de producir un millón de vehículos eléctricos para 2015 siempre contando con dinero público.
-¿Otro problema es que no se ha dado con un modelo único de coche eléctrico, que se trabaja en prototipos cada uno distinto y no se ha logrado unificar modelos que permitan su irrupción en el mercado a gran escala?
-El primer paso es contar con una instalación y suministradores para el coche a gran escala instaurados en múltiples lugares de repostaje. Mi coche, por ejemplo, puede recargarse con un enchufe de los ya existentes para grandes maquinarias, pero sus prestaciones son bajas comparado con su potencial: para recibir gran potencia eléctrica eso no está desarrollado tecnológicamente, porque permitiría cargas, recargas y alimentaciones más rápidas. Que no se tarde toda una noche sino poder hacerlo en una hora.
-¿Y pesa también la rentabilidad?
-Hasta que no se vea claro ese aspecto probablemente no llegará su definitiva implantación, como en tantos otros aspectos. Interesa que no contamine pero también que interese económicamente, tanto al usuario como al productor, porque el usuario cobrará por la electricidad que suministra a la red.
-¿La industria no se implica más porque teme que sea costosa su producción en serie?
-Hacer un coche elétrico es caro porque hay pocos y sus componentes, la electrónica de potencia, también lo son. Pero sólo es cuestión de innovación tecnológica y de avanzar en las investigaciones.
-¿Las petroleras mirarán con buenos ojos el que podría ser el final de su hegemonía de negocio?
-Hay compañías que se resisten a este tipo de propuestas porque no están en el negocio, pero no son sólo empresas petroleras. Creo, con todo, que es muy difícil para ellos tapar ya o evitar que se conozcan todos estos avances; pero si pueden, lo seguirán haciendo. Que no quepa duda. Pero no se pueden tapar más sus avances.
-¿Cómo es su prototipo?
-Tenemos sólo uno. Lo uso unos días para desplazarme y familiarizarme con él. Tengo enchufes en casa y en la universidad y puedo ir con él de una a la otra. Dispongo de autonomía para conducir 200 kilómetros, ir de Delaweare a Washington, pero no regresar. En mi opinión, su capacidad de aceleración actual es incluso superior a la que procura el motor de gasolina. No es menos eficiente. Hemos trabajado en el proyecto desde hace más de una década, 1997.
-¿Cuándo se podrá decir que estará implantado el coche eléctrico?
-Yo considero que hacia 2018 es una fecha razonable que la gente pueda comprarlo y usarlo en cualquier lugar.
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What is V2G?
Electric-drive vehicles, whether powered by batteries, fuel cells, or gasoline hybrids, have within them the energy source and power electronics capable of producing the 60 Hz AC electricity that powers our homes and offices. When connections are added to allow this electricity to flow from cars to power lines, we call it "vehicle to grid" power, or V2G. Cars pack a lot of power. One typical electric-drive vehicle can put out over 10kW, the average draw of 10 houses. The key to realizing economic value from V2G is precise timing of its grid power production to fit within driving requirments while meeting the time-critical power "dispatch" of the electric distribution system.
V2G Concept
The V2G concept is that battery, hybrid, and fuel cell vehicles all can send power to the electric grid, power that all three already generate internally. For battery and plug-in hybrid vehicles, the power connection is already there. For fuel cell and fuel-only hybrids, an electrical connection must be added. Red arrows indicate electric flow from vehicles to the grid.
Vehicle-to-grid (V2G) describes a system in which power can be sold to the electrical power grid by an electric-drive motor vehicle that is connected to the grid when it is not in use for transportation. Alternatively, when the car batteries need to be fully charged, the flow can be reversed and electricity can be drawn from the electrical power grid to charge the battery.
Vehicle-to-grid can be used with such gridable vehicles, this is, plugin vehicles (this is, electric vehicles as Battery Electric Vehicles (BEV) or Plug-in hybrid electric vehicles), with grid capacity. Since most vehicles are parked an average of 95 percent of the time, their batteries could be used to let electricity flow from the car to the power lines and back, with a value to the utilities of up to $4,000 per year per car.
One notable V2G project in the United States is at the University of Delaware, where a V2G team headed by Dr. Willett Kempton has been conducting on-going research. Their goals are to educate about the environmental and economic benefits of V2G and enhance the product market. Other investigators are the Pacific Gas and Electric Company, Xcel Energy, the National Renewable Energy Laboratory, and the University of Warwick.
V2G is a version of Battery-to-grid power applied to vehicles. There are three different versions of the vehicle-to-grid concept:
* A hybrid or Fuel cell vehicle, which generates power from storable fuel, uses its generator to produce power for a utility at peak electricity usage times. Here the vehicles serve as a distributed generation system, producing power from conventional fossil fuels or hydrogen.
* A battery-powered or hybrid vehicle which uses its excess rechargeable battery capacity to provide power to the electric grid during peak load times. These vehicles can then be recharged during off-peak hours at cheaper rates while helping to absorb excess night time generation. Here the vehicles serve as a distributed battery storage system to buffer power.
* A solar vehicle which uses its excess charging capacity to provide power to the electric grid when the battery is fully charged. Here the vehicle effectively becomes a small renewable energy power station. Such systems have been in use since the 1990s and are routinely used in the case of large vehicles, especially solar-powered boats.
The concept allows V2G vehicles to provide power to help balance loads by "valley filling" (charging at night when demand is low) and "peak shaving" (sending power back to the grid when demand is high). It can enable utilities new ways to provide regulation services (keeping voltage and frequency stable) and provide spinning reserves (meet sudden demands for power). In future development, it has been proposed that such use of electric vehicles could buffer renewable power sources such as wind power, for example, by storing excess energy produced during windy periods and providing it back to the grid during high load periods, thus effectively stabilizing the intermittency of wind power. Some see this application of vehicle-to-grid technology as a renewable energy approach that can penetrate the baseline electric market.
It has been proposed that public utilities would not have to build as many natural gas or coal-fired power plants to meet peak demand or as an insurance policy against blackouts. Since demand can be measured locally by a simple frequency measurement, dynamic load leveling can be provided as needed.
V2G could also be used as a buffer during power outages. As the New York Times explains:
“ [After a power outage, a Florida man] plugged his Toyota Prius into the backup uninterruptible power supply unit in his house and soon the refrigerator was humming and the lights were back on. “It was running everything in the house except the central air-conditioning” … As long as it has fuel, the Prius can produce at least three kilowatts of continuous power, which is adequate to maintain a home’s basic functions”.
However, at the present time many electric vehicle conversion owners, whose battery of choice is still lead acid with limited cycle lives and capacity, would prefer to use them to power their cars rather than load-balance the electricity grid.
Future battery developments may change the economic equation, making it advantageous to use newer high capacity and longer-lived batteries in BEV/PHEVs and in grid load balancing and as a large energy cache for renewable grid resources. Even if cycled daily, such batteries would only require replacement/recycling every 55 years or so. Since BEVs can have up to 50 kWh worth of battery storage they represent somewhat more than the average homes daily energy demand. Even without a PHEV’s gas generation capabilities such a vehicle could be utilized for emergency power for several days (V2H or Vehicle-to-home). As such they may be seen as a complementary technology for intermittent renewable power resources such as wind or solar electric.
University of Delaware
Dr. Willett Kempton, Dr. Suresh Advani, and Dr. Ajay Prasad are the researchers at University of Delaware who are currently conducting research on the V2G technology, with Dr. Kempton being the lead on the project. Dr. Kempton has published a number of articles on the technology and the concept, many of which can be found on the V2G project page. The group is involved in researching the technology itself as well as its performance when used on the grid. In addition to the technical research, the team has worked with Dr. Meryl Gardner, a Marketing professor in the Alfred Lerner College of Business and Economic at the University of Delaware, to develop marketing strategies for both consumer and corporate fleet adoption.
Electric cars that pay By Mark Clayton | Staff writer of The Christian Science Monitor
So, you’re thinking of buying one of those gas-electric hybrid cars like the Toyota Prius or Honda Insight. They’re trendy, conserve fuel, and reduce pollution. But to really go "green," some entrepreneurs and academics say, you should try a Volkswagen Jetta.
Not just any Jetta. A dark blue one that a California electric-car company has modified so that it not only uses electricity but generates it for other purposes. So, once it’s parked, you plug it in and sell excess electricity to a utility.
It sounds like a good way to meet car payments. But don’t start counting the cash just yet.
Neither big auto-makers nor utility companies have yet seized on the idea, known as "vehicle-to-grid," or V2G. Still, V2G is an idea waiting to happen – and the push toward hybrids today is making it ever more likely, say scientists, entrepreneurs, and economists.
"As electric-drive hybrids begin to penetrate the auto market, you now have distributed power generation on wheels," says Stephen Letendre, an economist at Green Mountain College in Poultney, Vt. "You also have an asset that’s sitting idle most of the time – just waiting to be connected."
Of the more than 235 million vehicles in the United States today, only a few thousand are hybrids. And these lack the extra internal circuitry and external plug necessary to give electricity back.
But if automakers were to make 1 million next-generation V2G vehicles by 2020, they could generate up to 10,000 megawatts of electricity – about the capacity of 20 average-size power plants, according to a 2001 study by AC Propulsion, the electric vehicle maker in San Dimas, Calif., that created the V2G Jetta.
While vehicles could generate plenty of power – studies show they sit idle 90 percent of the time – it would be far too costly to use as simple "base-load" power. Their main value would be in supplying spurts of peak and other specialty "ancillary" power for which utilities pay premium prices. It would be far cheaper for utilities to tap the batteries of thousands of cars, say, than the current practice of keeping huge turbines constantly spinning just to supply power at a moment’s notice, studies show.
And there would be little risk of leaving the office to discover a car with a dead battery. That’s because V2G cars would have on-board controls to prevent their batteries from being drawn below minimum travel needs set by the owner – say, a 50-mile trip.
There are signs V2G is beginning to generate more than just academic buzz.
• In Toronto, a V2G fuel-cell bus is to be in service in March.
• Power company PG&E is working with the electric industry’s research arm and a contractor to develop a fleet of V2G "trouble trucks" that could generate and deliver power to entire neighborhoods when a storm knocks out power.
• DaimlerChrysler has reported it is working on a version of its popular pickup truck with V2G capability for supplying power at a work site.
• AC Propulsion has plans to make as many as 1,000 V2G electric-drive vehicles starting as soon as next year.
• A major Florida city is on the verge of buying more than 50 battery-powered buses, including several that are V2G capable.
But it’s the idea of V2G on a larger scale that most awes Howard Ross, president of Ross Transportation Technology, which is getting set to build the Florida buses.
"There’s enough wind power in three Plains states to provide power to the entire country – but there’s no way today to store that power," Dr. Ross says. "If you have V2G auto storage, you can tap into renewables."
Wide use of V2G electric-drive vehicles could generate enough power to cut the requirement for central generating station capacity by as much as 20 percent by the year 2050, says the Electric Power Research Institute, a utility industry research center in Palo Alto, Calif.
But "if you asked 20 different utilities today what they thought of vehicles putting power back into the grid, you wouldn’t get a very positive response," says Mark Duvall, EPRI’s manager of technology development for electric transportation. "It took a long time to assure the utility industry that it was worthwhile just to plug solar and other items into the grid. It’s going to make them very nervous."
Today’s Toyota Prius battery pack is too small to make it a viable V2G option, says V2G pioneer Willett Kempton, who estimates it would add roughly $400 to a car’s overall cost. In the long run, fuel-cell cars will far exceed hybrids in their electric generating potential, he adds.
www.udel.edu/V2G/docs/Kempton-Letendre-97.pdf
www.udel.edu/V2G/docs/Kempton-Kubo-2000.pdf
www.udel.edu/V2G/docs/V2G-PUF-LetendKemp2002.pdf
www.udel.edu/V2G/KempTom-V2G-Fundamentals05.PDF
www.udel.edu/V2G/KempTom-V2G-Implementation05.PDF
www.udel.edu/V2G/docs/KemptonDhanju06-V2G-Wind.pdf
www.udel.edu/V2G/docs/LetendDenLil-LoadOrResource06.pdf
www.udel.edu/V2G/docs/TomicKemp-Fleets-proof-07.pdf
www.udel.edu/V2G/docs/V2G-Cal-2001.pdf
www.udel.edu/V2G/docs/V2G-Demo-Brooks-02-R5.pdf
www.udel.edu/V2G/docs/ICAT%2001-2-V2G-Plug-Hybrid.pdf
www.ocean.udel.edu/cms/wkempton/Kempton-V2G-pdfFiles/V2G.html
