The supply of electrical power is undergoing a fundamental change. Increasing numbers of local, flexible units—such as photovoltaic systems, combined heat and power plants, and so on—generate electricity; however these are often dependent on different variable factors such as sunlight or wind levels.

In addition to fluctuations due to varying power consumption, disparities in the electricity network can occur. At the same time, batteries in electric vehicles offer large storage potential and thus can offer an additional way to compensate for these fluctuations.

The INEES research project, which ran from 1 June 2012 to 31 December 2015, investigated the possibility of achieving a balancing and stabilizing effect on the power grid using a pool of electric vehicles.

Pooling batteries of electric vehicles offers a power storage capability of significant size suitable for mass consumption, which can compensate for fluctuations in the power grid. The vehicles could store excess electricity as well as put surplus energy back into the power grid.

For the one-year fleet trial, SMA Solar Technology AG developed a bi-directional DC-charging station designed as an experimental system in a small production run of 40 devices. Volkswagen AG equipped 20 e-up! battery-electric vehicles (earlier post) with a bidirectional charging function and built in a communication link between the charge controller and the Volkswagen backend computer center.

A mobile phone app was developed as a user interface. Participants in the fleet trial could use this app to see how their personal driving behaviour and the requirements of the electricity market are linked together. They allowed their vehicle battery to be used to support the power grid while basically experiencing no restrictions to their everyday mobility.

An incentive system, developed in the form of a SchwarmStrom (electricity from a cluster, earlier post) bonus, also contributed to the project. Participants received this as soon as they allowed some of their battery capacity to be released for general use.

Lichtblick, an energy and IT company, integrated the released electricity from the vehicles into the energy market using its SchwarmDirigent control software.

The study showed that electric vehicles can provide a safe and secure power reserve for the power grid with a short reaction time.

However, further analysis showed that the provision of balancing electric power by an electric vehicle pool is not economically viable under current conditions.

Planned legislative changes, further technical developments and the transformation of the energy system can significantly improve the economic factor in the future. The Fraunhofer Institute IWES analysis of the distribution networks load has shown that only network grids that are already heavily used today can expect short term shortages. In the medium term fluctuations in demand need to be allowed for when expanding the network.

The INEES research project—a German lighthouse project in electric mobility—was funded by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety.