Germany?s power grid could already handle 1 million electric vehicles

Germany’s utility industry believes that the federal government’s objective of having roughly 1 million electric vehicles on the country’s roads by 2020 would not pose any problems for the electricity grid. The future development of Smart Grids offers new perspectives and opportunities. In the future, electric vehicles could be used to as storage devices and help balance supply and demand. This would also ensure better integration of green electricity.

Smart meters would make it possible to charge the vehicles’ batteries at times when renewables output exceeds system demand, such as on windy nights. The vehicles could be powered by green electricity owing to planned increases in the country’s renewables capacity. These are the key findings of the interim report that the National Electromobility Platform’s “Charging Infrastructure and Network Integration Working Group” submitted to the German federal government on November 30, 2010. The working group is chaired by Klaus-Dieter Maubach, a member of the E.ON AG Board of Management, and Wolfgang Dehen, a member of the Siemens AG Managing Board and CEO of Siemens Energy Sector.

The members of the working group expect rapid advances in charging technology. By 2020, cable-free inductive charging and higher-voltage direct-current charging will make charging faster and more convenient. This would make e-mobility more attractive to motorists and increase its applications.

“It would be a mistake to set the technology bar too high for charging stations,” Klaus-Dieter Maubach says. “What we need right now are pragmatic, cost-effective solutions that will make e-mobility viable in the marketplace.” The volume of data exchanged between a vehicle and the network can be gradually expanded going forward. Because a smart charging infrastructure will not be necessary until a certain number of vehicles are on the road, deploying this infrastructure is a medium-term objective. The charging infrastructure installed now should be capable of being retrofitted with smart technology so that it can later be integrated in a smart grid.

Integrating up to 1 million electric cars by 2020 will generally not be problem for the power grid. Only in cases of a locally high density of electric cars could isolated segments of the grid be overloaded and possibly require upgrading. Nevertheless, the addition of new load (like electric vehicles) and especially the growth of intermittent generation resources (like renewables) are fundamentally transforming the energy system. Today’s infrastructure can only support this transformation to a limited degree. “Deploying smart controls across the network is necessary, in part to ensure that electric vehicles can be powered by green electricity. Smart-grid technology is already available today,” Wolfgang Dehen says. “Germany must rapidly lay the groundwork for deploying a smart grid.” The working group recommends that the necessary investments should be factored into Germany’s incentive-based network regulation scheme.

The government’s target number of electric cars could easily be powered by renewable-source electricity. One million electric cars would consume at most 2 billion kilowatt-hours of electricity a year. According to current forecasts of renewables growth, Germany will produce significantly more than 100 billion kilowatt-hours of green electricity in 2020. Theoretically, this would be enough to supply 50 million electric vehicles.

The report of the National Electromobility Platform’s “Charging Infrastructure and Network Integration Working Group” can be downloaded from the German federal government’s website and is available on request from Siemens and E.ON.