Batteries of electric vehicles get their energy from the power grid. They are also capable of sending the stored energy back into the electrical power grid as a component of a smart electric grid instead of being simply a consumer of energy.
The Car as Storage
On the average, consumers use an electric car for only about an hour a day. In effect, it stands idle for the rest of the day, which could be effectively used as temporary battery storage. The electricity stored in the vehicle battery could be sent to the power grid during the period of increased energy demand. The stored energy in your electric vehicle could even power your home during the peak hours of energy use. This is the idea behind the Vehicle-to-Grid (V2G) technology that is currently tested by the U.S. Department of Defense and various technology and energy companies.
The Vehicle-to-Grid technology aims to regulate the frequency of the electric supply, reduce the cost of electricity purchased during peak times, and increase the power output of the grid. Electric car batteries store electricity when they are not in use. The technology will make it possible to transfer back the energy to the grid during the car’s idle times.
Separate Studies, Opposing Views
The concept for this new technology is the offshoot of two separate studies conducted on the subject by Dr. Kotub Uddin at the University of Warwick and by Dr. Mattieu Dubarry at the Hawaii Natural Energy Institute. One study suggested that pumping energy back from the battery into the grid could damage the car batteries. The other one suggested that pumping back energy into the grid has the potential to improve battery life. The two scientists were able to show that their seemingly contradictory studies point to the same outcome – pumping back energy into the grid stabilizes energy supply.
The two authors agreed that to make the new technology economically viable, it requires the optimization of V2G technology between the requirements of the electric vehicle owner and the capability of the electric grid. It requires a balanced approach between the vehicle owners and the grid system.
There are obstacles ahead prior to perfecting and adoption of the technology. It is necessary to convince electric vehicle manufacturers that the use of EV batteries to store energy will not diminish the performance of the vehicle or the miles traveled. The EV manufacturers need assurance also that the electric grids would be willing to pay for the features.
The testing phase of the technology by the Defense Department found support in California where the electric utility company Edison International partners with them and the State of California in determining the viability of the concept.
A separate project led by the Electric Power Research Institute, together with regional transmission organizations and EV manufacturers, is conducting an Open Vehicle-Grid Integration Platform software system to test the viability of the technology. The VGI technology, a cloud-based translation system, will enable utility companies to communicate with vehicles produced by different EV manufacturers.
On the part of the EV manufacturers, they have developed communications standards that are unique for their respective vehicles. The next step will be the development of a standardized utility interface that will act as a universal translator that will allow utility companies to communicate with all EVs.
It is still a long way to go before V2G becomes an integral part of the electric grid system, however, researchers are taking steps towards that goal.