Bonn wants to establish a solar requirement on the roofs of new construction projects via urban development contracts. On Thursday evening, the city planning committee unanimously approved mandatory photovoltaics. Some exemptions would be possible.
In the future, the city will make the installation of photovoltaic systems on roofs mandatory for new construction projects. Following the environment committee on Thursday, the city planning committee also unanimously approved a corresponding draft resolution from the administration. A broad consensus is expected in the city council on September 16.
The administration wants to establish the solar requirement via urban development contracts within the framework of binding urban land use planning. Such contracts are usually made between the public sector and private investors together in the development planning procedure.
This means that, subject to the approval of the city council, all those construction projects for which new building rights are created via a development plan would be covered by the requirement. All current so-called B-plan procedures would be affected as well. Investors would not necessarily have to install and operate such systems themselves. This would also be possible via solar cooperatives or other operators such as the municipal utility. The latter have already concluded corresponding contracts with the city on some municipal buildings.
City describes criteria for exemptions
The urban development contract only allows such a requirement if "the measure is appropriate," according to the administration. For this reason, the city has spelled out some scenarios in which such a requirement could be waived. The contracting party would have to prove that the installation is not possible for economic reasons, that a solar thermal system already provides part of the heat supply, that technical requirements are lacking or that the protection of historical monuments stands in the way of a photovoltaic system. The solar requirement can also be waived in the case of a green roof, which is mandatory for some buildings according to a council resolution from 2010.
With this decision, the city wants to move closer to its goal of becoming climate-neutral by 2035. According to the latest CO2 assessment, electricity in Bonn generates a quarter of total emissions. The solar registry, in turn, indicates that more than half of the city's electricity needs, 53 percent to be exact, could be met by solar installations if all suitable roof surfaces were used for this purpose. Currently, the share of electricity generated by photovoltaic systems is a modest 2.1 percent.
Bonn goes its own way in North Rhine-Westphalia
With the solar requirement, Bonn is taking a special path in NRW. Achim Helbig, responsible for environmental planning at the city, said: "It would be welcome if the solar requirement were to be given a uniform framework either via the state building code or federal legislation, so that not every municipality has to go its own way."
Helbig continued, "We as a city would like to see a mix on the roofs of solar and greening, but today we still have reservations about the economic viability of that combination."
The proposal was aimed at requiring a mix of greening and photovoltaics but if this was not possible due to financial reasons, the administration would decide what made the most sense.
Solar requirement does not apply to existing houses
Andreas Zauke, department head for Zoning and Planning Law, was less than enthusiastic about this political move at the meeting, saying, "We're not happy with it. To determine the economic viability of solar, we have good tools." But when it comes to a green roof, the city lacked the tools to be able to calculate its economic viability. The city administration is expected to keep an eye on whether instruments for calculating the profitability of green roofs will be available in the future.
Existing houses and new houses for which building rights already exist are not covered by the solar requirement. This includes, for example, construction projects on land that is permitted under Section 34 of the German Building Code without a development plan. For private owners, 500,000 euros are earmarked in the future to provide additional incentives for investing in photovoltaic systems. In the two subsequent years, a further 250,000 euros per year are earmarked for that purpose. Orig. text: Philipp Königs Translation: Carol Kloeppel