Revista LA FUNDACIÓN

Menu
Loss experience in wind farms

Loss experience in wind farms

By In Destacados 2, Destacados 2, Sin categoría @en On 15 December, 2015


This article contains the main conclusions of the “Study of the Loss Experience in Wind Farms” produced by MAPFRE GLOBAL RISKS Engineering Department.

The study analyses the main factors that affect the claims experience in the electricity generating activity at Wind Farms, based on a representative sample (see Figure 1).

Figure 1. Details of the sample
  • Total population of 1,621 files from 1,121 claims.
  • Sample of 159 claims analysed in detail (representative sample based on the severity of the damage and availability of adjuster’s reports).
  • Insured groups studied which are amongst some of the main wind energy generating operators worldwide and account for 12% of the world installed power market share. (Source. World Wind Energy Association). Their market share is concentrated in 8 of the 10 main wind energy production markets (Germany 0.7%, Canada 6.5%, Spain 63.30%, France 4.2%, Italy 12.9%, Portugal 22.1%, UK 18.9%, USA 19.9%).
  • Claims period: 2008-2012.
  • Age range of wind turbines: 1991-2012.
  • Relationship between output and sums insured:
    • Average property sum insured: €1.2 M/MW.
    • Average business interruption sum insured: €180,000/MW/year – €500/MW/ day on average.

The average amount for the claims analysed is €731/MW/day, i.e. 46% higher than the declared average. This is probably due to the underestimation of the declared production sums insured.

The main factors in the loss experience for Wind Farms

The equipment, the manufacturer, the age and the size of the wind turbine and the amount of the self-insured deductible are the main factors that affect the loss ratio in this sector.

  • Equipment: The most significant component affecting the claims history is the blade. The blades, gears and main shaft have the biggest effect on the Property Damage experience and the blades together with the substation transformer are the most significant in Business Interruption losses.

Mechanical causes are the most common, with the gearbox being the most affected. Electrical causes arise, fundamentally, in the substation transformers and turbines. The most seriously affected by atmospheric causes is the distribution equipment and blades (see Figure 1).

Following the technological advances in wind turbines, certain circumstances have had an impact on the cost of repairing damage, such as:

  • The replacement of assembled parts that cannot be substituted or replaced individually, particularly in the case of blades and gears.
  • The limited availability of spare parts.
  • No open market for spares in this industrial sector.
  • Rapid wear due to operating conditions.
Figure 1: Relevance of the loss ratio of the different equipment in wind farms

Equipment where loss originated

No. of claims

PD

BI

PD+BI

Average unit cost

% of PD+BI

% of PD+BI

%

Total (€)

%

Main shaft

9

10%

1%

11%

604,057

203%

Generator

15

4%

1%

5%

152,582

51%

Gearbox

52

16%

2%

18%

162,328

55%

Blades

64

22%

5%

27%

202,467

68%

Distribution Network

3

8%

2%

9%

1,493,758

502%

Main bearing

1

0%

0%

0%

156,574

53%

Tower

1

3%

1%

4%

1,901,231

639%

Substation Transformer

6

5%

14%

20%

1,538,969

517%

Other equipment

8

2%

0%

5%

305,560

103%

General Total

159

72%

28%

100%

297,746

100%

  • Age. The 8 to 12 years age group range has the highest impact on claims ratios, with large fire claims and tower collapses being the most significant.There is a significant increase in damage after two years when the equipment is no longer covered under the manufacturer’s guarantee. Relevance[1] with a value in excess of 1 is observed up to 5 years in age and the group of between 5 and 8 years in age behaved the best.In the portfolio studied, the installed/start-up capacity for the 2007-2010 period represented over 50% of the equipment currently installed.With regards to age, the group with the most operational activity for the overall period analysed was for 3 to 5 years.

The working life of a wind turbine is estimated to be 25 years. There is little experience or information of value on wind turbines going back more than 15 years. In fact, the first wind turbines, which were older than that, were located at sites with the best wind conditions and are being replaced with larger, higher-performance equipment.

  • Medium-sized wind turbines (400 to 900 kW) have a higher relevance index (1.61), although this factor may be linked to age. In recent years, the equipment dimensions have increased and, as a result, the generating capacity.

Whilst the turbines in the 1,300 to 1,700 kW range and 1,700 to 2,100 kW range account for approximately 30% of the volume of activity, the first group accounts for 36% of total gross claims whereas the latter only accounts for 15%.

  • From the analysis on the effect of deductibles, for both the amount of damage and the waiting period for business interruption, it could be appreciated that with an MD deductible of €50,000, for example, the insured would have to bear approximately 20% of the total cost of claims, whereas, with an MD deductible of €100,000, the percentage borne by the insured would rise to 36%.Moreover, for the insured to bear 50% of the BI amounts, a time deductible of 26 days was calculated.

Criteria for calculating PML

A critical event, based on claims experience, is considered to be a major breakdown or fire/explosion that requires a long period of reinstatement for the installations that are supplying into the power grid.

For a large wind farm of around 200 MW, the gross claim amount would be €46 M, approximately 15% of the PD+BI sum insured for the farm or farms connected to the substation. With major exposure to tornadoes (e.g. USA), it is estimated that the gross claim would be around €120 M, i.e. approximately 40% of the PD+BI sum insured.

Wind turbines are not considered particularly vulnerable to earthquakes or floods.

Conclusions

The extent of this activity has produced considerable claims experience which has enabled the identification and evaluation of the different elements that have had the biggest impact on claims experience (blades and gearboxes), as well as other relevant factors (age, output, impact of deductibles, etc.).

[1] Relevance: An indicator that reflects the quotient of the total claims divided by the amount of activity for each group. Values in excess of 1 reflect a higher than average loss ratio and values below 1are lower than average.


About the Author

rv_fundacion

Comments are closed here.