Renewable Energy Powered Membrane Technology. 2. The Effect of Energy Fluctuations on Performance of a Photovoltaic Hybrid Membrane System

摘要

This paper reports on the performance fluctuations during the operation of a batteryless hybrid uitrafiltrstion-nanofiitratioiV reverse osmosis (UF-IMF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized using four different NF membranes (BW30, NF90, ESPA4JFC-S), and examined in more detail for the BW30 membrane. On an Australian spring day, the system produced 1.1 m~3 of permeate with an average conductivity of 0.28 mS·cm~(-1), recovering 28% of the brackish (8.29 mS·cm~(-1) conductivity) feedwater with an average specific energy consumption of 2.3 kWh-m~(-3), The RE-membrane system tolerated large fluctuations in solar irradiance (500-1200 W ·m~-(2)), resulting in only small increases in the permeate conductivity. When equipped with the NF90 fcloudy day) and ESPA4 (rainy day) membranes, the system was still able to produce 1.36 m~(-3) and 0.85 m~(-3) of good quality permeate, respectively. The TFC-S membrane was not able to produce adequate water quality from the bore watertested. It is concluded that batteryless operation is a simple and robust way to operate such systems under conditions ranging from clear skies to medium cloud cover.