Wind turbines
Wind turbines need protecting against moisture
Wind turbines are a big investment that has to be recouped over many years. Reliability and servicing needs play a big part in ROI, even when the wind turbine has notched up 15 years of service.
Moisture is one of the biggest potential causes of damage in wind turbines. However, such damage doesn’t just show up immediately – it’s a slow process over many years.
Surfaces inside modern wind turbines are well protected with different coatings and paint, but this doesn’t deal with the basic problem. Any moisture present inside the structure gives rise to corrosion, bacterial growth and condensation that causes short-circuiting and damage to electronics.
Offshore wind turbines face the biggest problems
It’s impossible to make any wind turbine air-tight. Offshore installations will inevitably suffer from salt-laden air entering both the nacelle and the tower. The many different salts will be deposited on surfaces inside. These salt formations gradually absorb moisture from the air, kick-starting a galvanic process that results in corrosion.
Read more about these challenges in the Dehumidification of offshore wind turbines.
There are 3 basic ways of dealing with unwanted moisture:
Cotes dehumidification systems can reduce the levels of moisture in the air. When humidity is below a certain level, the chemical salts are physically unable to absorb sufficient moisture for the corrosion process to begin. This then also protects fixtures and structures against electric short-circuiting and the effects of condensation.
Heating can be used to reduce the relative humidity. In terms of energy costs, this is normally 15–30 times more expensive than dehumidification. Furthermore, heating is incapable of removing any moisture present, resulting in risks of short-circuiting, corrosion and the effects of condensation on cold surfaces.
Doing nothing, and hoping any surface coatings will be sufficient to protect against the effects of corrosion and condensation.
Cotes has over 10 years of experience supplying special dehumidification solutions for offshore wind turbines.
Preventing condensation in the towers
Condensation is a problem in wind turbines both on land and offshore. This is usually seen when the inner surfaces are wet, sometimes to the extent of pools of water forming. This is all the result of the air inside the tower having a dew point lower than the temperatures of the surfaces in question.
Dehumidification is the only practical way to deal with condensation issues. Reducing the amounts of moisture in the air also reduces the dew point. If the dew point is then kept below the temperatures of the surfaces in the tower, condensation simply cannot arise.