Residential Wind Turbines: Maintenance Issues and Cost

Maintenance of a residential wind turbine falls into two categories: preserving the efficiency of the system and ensuring its safe operation. Fortunately, modern turbines have few moving parts and are designed to operate for up to 120,000 hours or roughly 15 years. (Some models claim a 20-year operational life.) The estimated cost of annual repairs and maintenance is about 2.5 to 2 percent of the original cost of the system, or about 0.01 cents per kilowatt hour.

This is not to say, however, that home turbines do not require regular attention, in particular oiling and greasing. Regular safety inspections are also a necessity. Issues of corrosion or loose bolts must be dealt with immediately, particularly on the tower and in the areas around the rotor blades to prevent damage from unchecked vibration. Electrical connections should be examined by a qualified electrician annually at minimum.

Residential wind systems are generally outfitted with various fail-safe measures. For instance, grid-tied systems are designed to detect outages and to shut down immediately, thus eliminating potential dangers to anyone working on the electrical utility lines. Stand-alone, off-grid wind units are connected to the home's electrical systems only and do not present such dangers.

Depending upon the material used for the blades, periodic replacement for cracks may be required or the leading blade edge may need to be re-taped to ensure the efficient flow of wind over the surface. Most blades today are made of fiberglass composite, rather than wood, which was obviously more susceptible to wearing. The original quality of the equipment and local climate conditions, in particular the degree of wind turbulence to which the unit is subjected, are the dominant factor in fatigue loads.

The effects of icing on rotor blades has been all but eliminated by design improvements. Early models allowed chunks of ice to fly off the blades, potentially damaging the turbine and representing a danger to anyone in proximity to the unit. On newer models, however, ice simply slows down the rotation of the blades, allowing the ice to eventually melt and fall straight down toward the tower's base.

It is normal, after ten years of operation, for rotor blades, the gearbox, and the bearings to require replacement. A decrease in the turbine's electrical efficiency or an increase in the mechanical noise it makes generally alert owners to the need for a professional service call. The price of a gearbox or a generator is roughly 15 to 20 percent of the original price of the turbine.

In most cases, the cost of a professionally installed system will include service for a set period of time, which can generally be extended. Turbine owners can learn to monitor their own systems for obvious damage through visual inspection, simply listening to the turbine while the unit is in operation, and by keeping records on the amount of energy it generates. Malfunctioning or damaged rotor blades are easy to spot, and mechanical noises are impossible to ignore, as are spikes in the monthly electric bill indicating the turbine is not operating at peak efficiency.

Barring physical damage to the residential wind turbine from sources beyond your control, like severe weather, expect low maintenance issues and expenses. This is good news, as it lowers the total cost of owning a home wind system. Continue reading to learn how energy tax credits and state, federal, and private incentives can further lower your wind energy investment.