Economic considerations and cost comparisons between the heat pumps and solar collectors for the application of plume control from wet cooling towers of commercial buildings

This communication presents a case study based on the economic considerations and comparisons between the heat pump and solar collector heating systems for the application and utility to control the visible plume from wet cooling towers of a huge commercial building in Hong Kong. A detail economic study for both cases, i.e. for heat pumps as well as for solar collectors is done and compared using different (capital and operational) costs, taking other constraints into account. The capital cost is the actual cost of the device, for example, for a heat pump it is the cost of the heat pump machine. For a solar collector it is the cost of all the components like the collector, pipes, pump, heat exchanger, etc. On the other hand, the operational cost is the cost that keeps the system working in good condition. For a heat pump, the cost of the input power to the compressor is the running cost, while the necessary maintenance and replacement of parts comes under other cost. Similarly, for a solar collector, the cost of the power consumed by the pump/compressor to circulate the working fluid is the running cost which is very less as compared to the former. It is found that all the costs are much lesser for a solar collector system while it is reverse in the case of an air-cooled geothermal heat pump system. Other comparisons between the electric and geothermal heat pump systems are also given among different possible options.