Design and implementation of a ’combined energy and water system’ for 5* hotels and spa by SYCHEM SA.
Mirragio resort, owned by SYCHEM SA, implements a combined system for water management and energy production using sea water and electrical energy to provide:
•Space cooling and heating
•Underfloor and domestic water heating
•Pool & spa heating and cooling
•Domestic water production (reverse osmosis desalination)
•Sea water supply for Thalassotherapy Center
•Sea water and brackish water supply for pools re-filling
•Heat rejection for hotel’s centralized refrigeration systems
The system’s innovation lies into the joint use of the mechanical equipment and resources (sea water, electrical energy, reclaimed heat) for several combined uses, under the control of a sophisticated Building Energy Management System (BEMS). The main synergies of the combined system are:
•Extensive in-series reuse of the sea water by water-source schillers, water-source heat pumps, desalination plant, centralised refrigeration, thalassotherapy and pools. The route of the sea water is controlled according to the specific temperature requirements of each sub-system. The result of sea water reuse is the substantial reduction of sea water intake infrastructure and pumping energy.
•Reclaim of waste heat by water-source chillers for pool’s heating and underfloor heating
•Reclaim of waste cool by water-source heat pumps for space cooling
•Use of thermal springs for pool’s heating
Total cost for design, built and commissioning: € 1.900.000
Design personnel: 4 engineers
Built personnel: 3 engineers, 12 technicians
Commissioning personnel: 4 engineers
Evidence of success
The system is still in trial operation (operates from June 2016) so the energy and water consumption data are not yet reliable. The energy benefit of the ‘Sea water GeoExchange System’ as opposed to conventional systems of air-cooled chillers and gas-heater, is estimated to € 216.000 annually. The reduction in greenhouse gas emission is estimated to be equivalent to 632 tons of CO2 annually. Moreover, the ‘combined energy and water system’ is entirely hidden in the basement.
The biggest challenges were the sea water intake and the BEMS control system. The sea water intake should provide clean sea water of low temperature with minimal solids content.
Potential for learning or transfer
The energy and water problems that triggered the introduction of this practice, are the same for most Mediterranean Resort Hotels. The main idea of the ’combined energy and water system’ may be adapted to the specific needs of each hotel, that will benefit from the inherent advantages of the system.
In addition, local and national authorities can take advantage of the results of such good practices on water management and energy production and included these technologies in their policies regarding tourism. The promotion of such policies in public tourist facilities will help attracting new tourists.