Potential of Micro Gas Turbines to Provide Renewable Heat and Power in Off-Grid Applications for Desalination and Industrial Wastewater Treatment

The demand for all types of resources (food, freshwater, energy and raw materials) has increased alarmingly due to the continuous techno-economic development of society, bringing about a pressing shortage not only in low-income countries but also in more developed economies. Such is the case for the very wealthy countries in the Gulf Cooperation Council, which are currently struggling with the lack of fresh water supply, or certain countries in Latin America where the contamination of natural water sources poses a major environmental threat. In order to assess this water-energy nexus problem, this paper looks into systems where the production of renewable power is combined with either freshwater production (through desalination) or industrial wastewater treatment for effluent control. Three enabling renewable energy technologies are assessed: solar micro gas turbines, wind turbines and photovoltaic panels. In all cases, off-grid installations are considered. The paper describes the characteristics of these three systems and provides a comparison of technical specifications, yield and costs. Wind and photovoltaic are the standard approach, as already proven by a number of commercial plants, but solar micro gas turbines exhibit additional flexibility (in particular when hybridisation is considered) and have the differential feature of producing not only electric power but also heat. This enables the combination of different types of water treatment technologies in order to increase water production/recovery which, in turn, reduces the environmental impact of the production process associated (either freshwater or other good or service).