Planning and execution of construction work, in particular renovations of old buildings, new and conversion constructions, renovations; planning, construction and operation of plants in the field of renewable energies; trade, development and sale of alternative solar energy systems, wind energy systems, panels, solar cells and solar modules as well as offering corresponding services; in this context, it can rent, sell or lease suitable areas for the creation of photovoltaics and photovoltaic components; acquisition or sale of real estate.