Tar Chalome, a vast wetland south of Bangkok, is known for crocodiles, poisonous snakes, and spicy seafood. Now, it will be known for a powerful contradiction of terms: the world’s biggest small wind farm.
More than two dozen towers rise from the wetland, each holding 10 small-wind turbines. Locals, struck by the complexity of the towers, say the project looks like a quivering forest, the turbines spinning like leaves on steel branches. They have built a temple on nearby land to pray for increased energy production and safety for wind technicians.
But why construct a small-wind forest? The project owner had tried larger turbines in the past, only to be disappointed by their output. The wind resource in Tar Chalome is light to medium at best. The idea for an array of small turbines struck a local contractor, but the project owner remained dubious.
To prove the concept, the contractor built a 100m tower with a single Osiris 1.6 turbine at the top. The small size of the 78-kg system is deceptive. Osiris 1.6 showed an estimated annual energy production up to 3,500 kWh with wind at 6 m/s.
A year of test data convinced the client that a small wind farm would work better than a single large turbine system, and the world’s biggest small wind farm was soon built.
The Osiris 1.6 Turbine
Rated capacity: 1.6 kW
Start-up wind speed: 2.4 m/s
Rated wind speed: 10.5 m/s
Survival wind speed: 50 m/s
Generator: Direct drive permanent magnet (NdFeB)
Weight: 78 kg
Rotor diameter: 3.2m
Yaw control: Passive
Grid tie: Programmable transformerless 220/240 VAC 50-60 HZ