Commercial solar in the Canton of AargauSolar duty from 300 m².

Rules for businesses in Aargau

When new buildings with more than 300 m² of countable building area are built, federal law requires a solar system on the roof or facade (Art. 45a EnG). Aargau sets out the exceptions in § 26a of its Energieverordnung. The modules must cover at least 20 percent of the countable building area. You are exempt if you may not build in zones with heightened townscape requirements, or if the system is economically disproportionate. That is the case if it does not pay for itself within 25 years or produces less than 70 kWh per m² a year. For halls, warehouses and workshops, the system is therefore part of the planning.

For existing buildings, you notify the municipal council (Gemeinderat) of roof systems through the EVEN platform. The deadline is 30 days. Ground-mounted systems, protected buildings and protection zones need a building application. We put the documents together.

Large energy consumers (Grossverbraucher)

Aargau implemented the federal large-consumer article in 2012 (§ 3 and § 10 Energiegesetz, § 27 Energieverordnung). A large consumer is a site that uses more than 0.5 GWh of electricity or more than 5 GWh of heat a year. The options are the universal target agreement with the federal government, the cantonal target agreement and the energy consumption analysis.

Subsidies and one-off payment

The federal government pays the one-off payment (Einmalvergütung) through Pronovo, graded by system size. We submit the application and, on request, pre-finance the subsidies. The cantonal 2026 subsidy programme does not support the system itself directly. It has a photovoltaic bonus if the roof or facade of a building with a building permit from before 2000 is insulated at the same time. The application must be submitted before work starts. For depreciation in business assets, your tax adviser can advise you.

Self-consumption in your business

If you produce or cool during the day, you use the solar power directly. We read out your load profile data and size the system accordingly. A battery storage unit or an EV charger for company vehicles raises self-consumption further.