Combining water and energy supply

This study explores the feasibility of a distribution and storage system that supplies both heat and cold based on local sources and drinking water to buildings. By combining thermal energy and drinking water supply in one network would save on underground distribution network. This study was conducted as part of the Dutch research programme 'Knowledge for Climate'.A conceptual framework is provided to determine 1) heat demand of an urban area, 2) heat yield of the urban water system and 3) heat storage capacity of the urban aquifer system. This framework is applied to a mainly residential suburb of Amsterdam. Results show that 25% of the demand can be provided by the urban water system and cycle in a time period when it can be used directly. A further 75% of heat is available in periods when there is no demand. Aquifer thermal energy storage can provide enough heat storage to provide a solution for the temporal mismatch between energy availability and demand.The overall energy performance of using the urban water cycle for heat supply and storage was compared to the primary energy consumption of a traditional system. The Epr of this system compared to a traditional system shows a 7% reduction. Key factors limiting the energy savings are the seasonal performance factor and the conversion factor of primary energy to electrical energy.The urban water system can provide an effective source of heat for urban areas. However, a more detailed design and more research are on both the thermal and economic efficiency. Delivering both drinking water and thermal energy using the same network does not seem feasible. The water quality in the combined distribution network can not be guaranteed to meet consumption standards. Point source purification can be used as a solution, but the higher cost for providing drinking water and the slightly increased health risk are expected to outweigh the advantage of saving on one distribution system.