Geothermal energy can be used directly as heat for many applications such as building and district heating, industrial process heating, commercial uses such as greenhouse heating and temperature control of water for fish farming, bathing and swimming, and many other uses. Many applications are well developed and are economically viable, while others are challenged by implementation difficulties and unfavourable economics. The Direct Use Annex will address all aspects of the technology with emphasis on improving implementation, reducing costs and enhancing use.