Committing and dispatching power units and storage devices in cogeneration systems with renewable energy sources

This paper deals with optimal short term unit commitment and load dispatch for power systems with combined electricity and heat supply including energy storage devices. Future-oriented power systems with an appreciable amount of renewable energy sources and corresponding storage demand are considered for simulation. The modelling of storage devices for short term operation planning is presented in the paper. The principle of thermal energy storage in district heating network pipes and its consideration by a storage device model is described. The paper also contains calculations of case studies. Results of investigations with and without storage devices in otherwise identical power systems are compared to analyse the potential of savings in operational costs. The results may point out to which extent the potential benefits of energy storage may justify the capital expenditure necessary for the installation of a storage device