(1) The purpose of this law is to enable a sustainable development of the energy supply and to promote the further development of technologies for the generation of heat and cold from renewable energies, in particular in the interest of climate protection, the conservation of fossil resources and the reduction of dependence on energy imports. (2) In order to achieve the purpose of paragraph 1 while maintaining economic viability, this law aims to contribute to increasing the share of renewable energies in final energy consumption for heating and cooling to 14 percent by 2020.  1a Exemplary function of public buildings