Maintenance

1) Nicholas Leighton (90)
Supplies 100 jobs for the average WTpower plant.
WT less than conventional forms of conventional generation.
Usually twice per anum with about 12 - 18 hour downtime for each event.
1Megawatt plus WT's are coming out with maintenance warranties.
Modern WT's are designed to run for about 120 000 hours.
Maintenance cost increases as WT's age.

Danish WT's studies show cheaper maintenance in newer generation WT's.
Older WT's of 25kWh - 150kWh are about 3% of purchase price per anum.
Newer WT's are about 1.5 - 2%.
Most of cost is a fixed amount pa for regular services but a fixed amount of kWh is generally preferred $0.01per kWh (wear and tear increases with increasing production)

Rotor blades and gearbox is more suseptable to wear and tear.
Major ovehauls are possible, i.e. blades, gearbox, generator at about 15% - 20% of original replacement price of the WT.