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Low-temperature residual heat and heat potentials of renewables below 70°C often stay unused as either the distance between source and demand is too large or the heat does not occur at demand times. Hybrid thermo-chemical networks have a high potential to improve this situation, to transport thermal energy potential over long distances and to bridge short to medium time differences between demand and supply. The storage and transport potential of thermo-chemical substances has been identified and examined comprehensively. However, none of the studies addressed the replacement of water by thermo-chemical fluids (TCF) in district networks. Therefore this paper elaborates the use of TCF in such networks. First, it elaborates technological application cases showing the theoretical potential to reduce primary energy consumption up to 85%. Second, it presents technological components that have been developed for thermo-chemical systems.

The geographical location of Mauritius near the warm tropical waters of the Indian Ocean coupled to the vast exclusive economic zone approximating 2.3 million square kilometers, encourage the promotion of ocean thermal energy conversion (OTEC) systems. Technological advancements have enabled offshore structures to pump the cold water lying at 1000 m depth in the seawater column to the surface, and through the temperature difference set up with the warm surface layer, drives a turbine and generates electricity. In this study, a model has been developed to compute the temperature difference between the deep (1000 m) and surface (20 m) seawater layers around Mauritius. An algorithm has been implemented to determine the net power generated from a proposed OTEC power plant, acquired through the processing of sea surface temperature satellite images, at a resolution of 1 km. The spatial and temporal variations of the net power generated has been observed by splitting the annual data into four monsoonal time frames. Results show that the south-western region of Mauritius possesses high OTEC resources, with annual mean daily net power generation capacity of about 95 MW, representing about 20% of the peak power demand of the island. Moreover, the bathymetry of the southern region is propitious due to deep cold water availability at a proximity of less than 5km from the coastline. The energy and exergy efficiencies of the OTEC system are found to be 1.9 and 22.8%, respectively. A cost-benefit analysis indicates that profits of the order of 4.5 times the initial investment can be generated.

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