Solar Cooling for Maldives – a case Study

Abstract

A study carried out by NASA showed that global temperature has risen about 0.8 0C, resulting an increase in sea level of about 3.24 mm per year. This increase is a huge threat to low-level countries like the Maldives, where around 80% of the islands are less than 1 m above the sea level. The Maldives lies on the Equator, having a tropical climate with an average temperature of 31 0C and plentiful of sunlight. It has a high demand for cooling, but its primary energy source (electricity) is from combustion of marine gas oil, a high carbon fuel. As being an environmental refugee and a signee of Montreal Protocol, it is important for the Maldives to minimise the CO2 emissions by utilizing low/zero carbon energy sources.
This paper, therefore, investigated a method to utilize solar energy to provide cooling for the Maldives, ultimately minimising the CO2 emissions. A thermal model of a typical office building was created using Autodesk Revit to calculate the cooling loads, which was then used for the simulation with the Polysun software. Vacuum tube solar collectors were used to provide hot water with the required temperature of 90 0C or above to drive an absorption chiller (LiBr-H2O), but only for the period of 11:00 AM to 06:00 PM. Therefore, a second simulation was carried out using an auxiliary powered tank, which helped achieve the required temperature all day. Finally the results were compared with a traditional vapour compression system (R134a) in terms of CO2 emissions and running cost.