One asset of e-mobility is how perfectly it can be combined with renewable energy. Electric vehicles can be driven and charging stations can be fed with electricity from PV systems. Ideally, electric vehicles are charged with solar power directly from the owner’s roof. Electric vehicles are notably more efficient than conventional fuel-burning vehicles. A PV system with a capacity of three kilowatts peak in a single-family home in Germany can provide enough power annually to operate an electric car for around 14,000 kilometers emission free. This will be of particular interest for all those PV system owners who will lose their eligibility for EEG subsidies in 2021 or later, once their installations are more than 20 years old. For them, completely new business models such as the operation of solar filling stations are also in the works, with many suppliers having already developed the necessary software. Innovative areas of business are also opening up in many other sectors. Some solar technology suppliers are expanding their business activities and cooperating with manufacturers to offer electric vehicles for sale or lease.
Avoiding grid congestion with energy management and battery storage systems
A field test in Fellbach, Germany, tested the functionality of grid management in conjunction with electric vehicles. The Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) has developed a household energy management system that optimizes electric vehicle charging to maximize the supply of self-generated power from photovoltaic installations. The system develops and monitors charging schedules, taking into account yield forecasts and the household load. This intelligent, foresighted control technology enabled the photovoltaic system to provide 86 percent of the charging power needed on a sunny day. Without the charging algorithm, it would have only achieved 46 percent.
With e-mobility, grid congestion can be prevented for the most part through intelligent coordination of renewable energies and storage systems. A current study conducted at the TU Braunschweig has shown that, by employing solar installations connected to battery storage systems, around 60 percent of all homes connected to the power grid in neighborhoods of private one- and two-family houses can be supplied by their own 11 kW charging stations for electric cars. This significantly relieves stress on the normal power grid. As of now, most new solar power systems are being installed with a battery storage system, according to the German Solar Association (BSW-Solar).
More and more initiatives are being started and ideas implemented. For instance, a new employee parking garage at an IT company in Neckarsulm, Germany, has been outfitted with a 750 kW PV rooftop installation, which provides most of the energy necessary to power 50 charging spots. Load management enables the power to be precisely distributed. For instance, if one employee were to need more charging power and another less, the load management would adjust the system accordingly. It can even decide if self-generated solar power should be used or if supplementary power should be purchased from the public grid.
Releated Conference Sessions:
Power2Drive Forum, Hall C3: Expert talks about „PV & e-Mobility“ chaired by the German Association for Solar Mobility (bsm), Thursday, May 16, 2:30 – 4 pm
Picture: Clickcon Photovoltaik Montagesysteme