The core activity of Energiehof AG is to build and operate solar power plants on unused roof surfaces to produce solar power. In doing so, the company assumes the costs for the system and offers the building owners various options, such as free use of solar power, discounted solar power, a fixed or variable income, or the takeover of the solar system after a few years. The company markets this as "roof rental", where the building owners make their unused roof surfaces available for a limited time.