- O&M costs for wind power are double or triple the figures originally projected; they are particularly high in the U.S.
- There’s a −21% change in wind farm return on investment. This underperformance of wind assets is most likely attributable to both differences in power production and O&M costs over original estimates.
- $0.027/kWh, or €0.019/kWh, is the average values of O&M costs obtained from report surveys. This compares to early estimates by one of the world’s dominant turbine suppliers of $0.005/kWh.
- A significant amount of R&D is currently going into gearbox reliability. Many gearboxes, designed for a 20-year life, are failing after 6 to 8 years of operation.
- Data suggests that O&M challenges for wind turbines peaked in 2007/2008.
- At 2 cents/kWh, O&M costs are roughly equal to the federal production tax credit offered in the U.S. as a subsidy to make wind energy competitive.
- Engineers are still scratching their heads when it comes to gearboxes. Even though gearboxes are certified to operate for 20 years, none of them on today’s market lasts more than 8 years.
- 66% – the percentage of offshore O+M costs that are caused by unscheduled corrective maintenance
- 2-6 times higher – offshore wind turbines O+M costs compared with on-shore
- 10% – the loss in revenue due to the effect of spattered debris accumulation on the blade’s leading edge
- €100,000 to €300,000 per year – the costs of keeping offshore turbines online vs. an allocation of €45,000 per turbine for onshore wind
As part of our research into failure rates, costs and downtime on US Wind Farms, we have built a model which estimates lifetime costs of scheduled maintenance for a wind farm in the US. The input data used to build this data pack is a 210MW wind farm made up of 105 2MW turbines of 80 metres in height. The tables below show component risk factors, periodic maintenance costs, failure scenarios and supply chain factors [all costs USD]. CMS [complete monitoring system] options play an increasingly important role in both mean time to repair and the time between failures. As a result they have a large impact on costs. These are also taken into account. Finally the data pack provides major component lifetime O&M cost for the wind farm.
Scheduled maintenance cost—
Frequency per year: 2
Cost per action per turbine: $6,000
Reduced cost: $5,100
Lifetime cost per farm: $21,420,000
Component risk factors—
|Components||Replacement cost||Failure rate (%), failures per 100 parts by year 20||Total failures in 20 years (total farm)||Average downtime per failure, days||Average downtime losses per faiure||Total downtime losses for the rest of the||Labor cost per failure||Crane cost per failure|
Supply chain risk factors—
|Spare in stock / No spare||Distance to manufacturing facility (if no spare available)|
|Available / No spare||Lead time, days||Close / Medium / Remote||Time for transportation, days|
CMS factors (per turbine)—
|Capital Sensor Cost (including installation) per turbine||Annual cost (O&M) per turbine||Detectability||Efficiency|
|Monitoring type||Cost||Reduced cost (economies of scale)||Fixed cost||Reduced cost (economies of scale)|
|Lifetime maintenance cost for the farm||Lifetime maintenance cost assuming secondary damage||Lifetime maintenance and CMS operation cost for the farm||Monitoring type|
We have also looked at failure rates across different turbine technology types and designs. The graph below shows major component failure rates for all types of turbines in our dataset during the first ten years of operations. Different failure modes have different repair times, ultimately leading to different costs.
This article is the work of the author(s) indicated. Any opinions expressed in it are not necessarily those of National Wind Watch.
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