Public acceptance of photovoltaics and the continued expansion of solar power increasingly depend on more developed land being used for PV. Parking lot PV, an efficient PV application that is now being subsidized, is a case in point: PV can be used on top of carports as well as for extensive canopies over large parking lots.
The advantages are clear: The dual use of developed land, with the canopy providing sun and weather protection and, in conjunction with EV chargers and charging stations, the electricity can be used right where it is generated.
Nowadays, parking lot PV systems offer supply solutions that go way beyond private solar carports. On a large scale, industrial companies and commercial enterprises are able to secure their own supply with solar power, while large parking lot facilities can help build a comprehensive charging infrastructure for e-mobility and, in turn, speed up the transportation transition as a whole. As a positive side-effect, operators gain a considerable boost to their reputation and implement effective measures to reduce carbon emissions in order to fulfill their climate protection obligations, as well as generating added value from parking lot areas. In addition, the roofing protects the surface of the parking lot. With parking lot PV and charging stations, municipalities can make a contribution to the mobility and energy transition.
In spite of all this, parking lot PV still has several hurdles to overcome. Owing to regulatory building specifications, both planning times and standards exceed those for traditional roof-mounted systems. Investment costs are also higher, as specialist roofing structures are included in the calculations.
Researchers at Forschungszentrum Jülich and RWTH Aachen University recently calculated the potential of parking lot PV in Germany based on a geospatial surface analysis, and taking into consideration the current laws and regulations. The study found that when it comes to existing parking lots, the combined technical potential of parking lots with more than 35 spaces is 24.6 gigawatts, that of all existing lots with more than 50 spaces is 22.2 gigawatts, and that of lots exceeding 100 spaces is 22.2 gigawatts. At 5 gigawatts, the state of North Rhine-Westphalia has the highest potential of all German states.
The problem, however, lies in the fact that the obligations adopted in different German states relating to parking lot PV currently only apply to new structures, and not to existing parking lots. Within Germany, new parking lots must be equipped with PV in the states of Baden-Württemberg, North Rhine-Westphalia, Rhineland-Palatinate, Lower Saxony and Schleswig-Holstein. With the Solar Package I, the German government introduced subsidies for parking lot PV by adding the application to the subsegment “special solar installations” in May 2024. Parking lot PV installations are now subject to a maximum bid of 9.5 cents/kWh. Whether or not parking lot PV receives funding from the German government also depends on whether or not the canopy is categorized as a structural component – in which case the remuneration is the same as that for normal ground-mounted systems: 7 cents/kWh.
In France, legislators have gone one step further: In July 2023, a blanket obligation to cover parking lots with a surface area of 1,500 square meters or more with PV. This applies to both new builds and existing lots.
The German state of Baden-Württemberg has shown how subsidies for parking lot PV can be effective by providing 1.5 million euros for 10 projects. The funding underlies the Parking Lot PV Program of the state Ministry of the Environment, Climate Protection and the Energy Sector.
The costs of installing parking lot PV are 50 percent higher than those of roof-mounted systems. This is because the modules must be mounted on a special substructure. The higher costs and the 7 cents/kWh remuneration mean that parking lot PV is only worth-while if it produces synergy effects, such as providing charging points for e-vehicles or reducing the amount of electricity a company has to buy from the grid. And of course, the benefit of having a cover for a parking lot must also be taken into account.
