Wednesday, March 14, 2012

Wind energy-that can save islands

Wind is a potential source of renewable energy, especially for islands with an average wind velocity of 5mts/sec and above. Many islands in pacific ocean have some common problems like sea erosion, shortage of power and drinking water. These small islands with little population are fully depending on diesel fuel. In fact their life depends on diesel fuel and any increase in price significantly affects their daily life. Their main source of income is only by fishing and they live day to day. I had a personal experience of visiting a small island off Port Moresby in Papua New Guinea. They call it Daugo Island or ‘Fisherman’s island’ with population of less than 700 people. It is about 4.5km wide and 2km long. It is a coral atoll pushed out of the sea. One can take stroll on the beach and it is one of the most beautiful experiences one can have. It gives a feeling that you are far away from the rest of the world. There is a small abandoned World War II Airfield. The people in the island do not have any electricity or drinking water, and most of them are fishing on small boats. Their boats are fuelled by diesel. They will go to nearby city of Port Moresby and sell their fish and with that money they will buy drinking water and diesel in cans, and return to the island. This is their daily life. Such an island is an ideal location to set up a wind turbine and a small sea water desalination plant, that can easily solve their problem of water and power. The trade wind from the Coral Sea in the island of Papua New Guinea blows almost 7-8 months in a year and their wind velocity averages 7 mts/sec. Two wind turbines of each 250 kW capacity and a small seawater desalination SWRO plant of capacity 15,000lts/day will be sufficient to solve their problems. The desalination plant will consume about 4.5Kwhrs/m3 of water generated. About 2000 kwhrs/day of power can be supplied to the village, each family consuming about 2.85 kwhrs/day for 6 hours/day and also for the desalination plant. The system will generate surplus power. Renewable wind energy is the best option for such islands to generate on-site power and also to desalinate seawater for supply of drinking water. With increasing global warming and sea level rising, these small island face seawater intrusion and inundation. Many islands are slowly disappearing into the vast sea. Moreover, these islands are the most vulnerable to the fluctuating diesels prices and they are walking on a tight rope.Industrialised countries with an average power consumption of several kilowatt hours per day are crying foul about rising energy cost while people in such small islands barely manage their food and shelter after paying for the diesel. Recently the Government of Maldives conducted their cabinet ministers meeting under the sea, to showcase their plight due to sea level rise caused by global warming, to the rest of the world. Small islands can cry loud but their voice is muffled by roaring sea, while rest of the world carries on their business as usual.