Car2Flex

The transport sector, especially road traffic, represents a high level of environmental pollution. With 23.7 million tonnes of CO2 equivalent and thus a share of 45.8%, the transport sector was the largest emitter of greenhouse gas in the latest climate protection report (2019) by the Umweltbundesamt GmbH -Emissions outside of emissions trading. Electromobility offers a possible solution to reduce this burden. However, smart and sustainable mobility concepts are needed to integrate electromobility into the energy system of tomorrow.

The lead project Car2Flex deals with three different user groups in electromobility: private users, e-vehicle fleets (e.g. in companies) and e-car sharing in apartment buildings. The focus is on the question of how – according to the mobility needs of the respective groups – the increasing share of electromobility can best be integrated. In addition, the Car2Flex concepts are intended to create new economic incentives. For example with solutions that increase the self-consumption of PV electricity (PV = photovoltaics) through intermediate storage in the battery of a vehicle. This optimized, flexible battery use can increase the share of renewable energy generation and use and save costs.

Optimized use of renewable energies through smart charging and discharging of e-cars

In the Car2Flex project, bidirectional DC charging points (direct current) are used, for example for the direct use of PV electricity, which can be used directly as direct current and no longer has to be converted into alternating current. Thanks to the bidirectional function, the charging station can also draw power from the car battery and not just the other way around, as is usual. Specially developed algorithms for optimized charging strategies, for example to reduce network peaks and to integrate between aggregator and booking platforms, are used here. A participation process with users and other relevant stakeholders (e.g. housing developers, charging station operators, etc.) accompanies the developments. The needs of private individuals and companies are taken into account.

A special focus in the Car2Flex lead project is also on e-car sharing providers. They own a large number of e-cars and can use the booking system (app) to track where, at which charging station and with what state of charge each e-car is located around the clock. Every single electric car offers the potential for additional flexibility, as it can be charged when there is excess electricity and discharged when there is a need for electricity. This is particularly interesting for aggregators who summarize (aggregate) individual flexibilities and market them.

The information generated about the various mobility behaviors helps to make more precise predictions as to how e-cars can be optimally integrated into the network. They provide information about when the e-cars are charged, how much they are moved on average and how much charge they will then need again.