The innovative approach of “Clean Energy for Tourism” (CE4T) is based on the integrative, systemic optimisation in relation to the three central areas of electricity supply, electricity market and large consumers. CE4T is developing optimisation algorithms, related interfaces and an ICT framework to maximise energy efficiency & integration of renewable energies and to use flexibility options for both power and energy demand of the tourism industry. Especially winter tourism is a very energy intensive sector, where new concepts are needed for the use of renewable energies in the cold season.