Case Study – Wind Power Generation

Case Study - WindmillThis wind turbine is used to supplement power in conditions of low sun to two houses that have moderate sized solar panel arrays as their primary source. Wind Turbine output is 400W max three phase 24 volt AC. It delivers up to 17 amps/hr on a windy day and is shared between the two houses. It is mounted on a wire stayed 13m tower that centre pivots with counterweights to allow one handed lowering of the turbine for servicing or extreme wind events.

The situation:
House 1. Intermittently occupied by off island owners .This elevated windy site was originally owned by house 2 who designed and built the turbine tower that is now owned by house 1. This house receives 1/3 of the turbine output .

House 2. Permanently occupied, is situated 150 meters from house 1 on a separate site. House 2 owns the wind turbine and regulators and has the technical ability to maintain the system. House 2 receives 2/3 of the turbine output.

House 2 has a 400amp battery bank at 24 volt DC . Daily consumption is 100amps @24 volt DC delivered to the house by an inverter as 240v a/c ( It is desirable not to use more than 25% of a lead acid battery bank capacity per day ). On an average windy low sun winter day up to 10 amps per hour from the turbine will be generated, not a lot compared to solar hourly output but wind may be available for 24 hours whereas the solar input is approx 7 hours. The turbine only has to average 4.2 amps/hr over a 24 hr period to meet household needs.

On those rare days when there is no sun and no wind a 1920’s technology Lister slow revving diesel provides back up. These are incredibly economical and readily available new. The house model uses 800ml of diesel ($ 1.35/litre on island ) an hour running the house as well as 35 amp charger to top up our batteries . This requires 3hrs a day at a total cost of $3.24 .



Windmill supplier and installer.

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Last updated on the 06-04-2020