Home » Posts tagged 'offshore wind energy'

Tag Archives: offshore wind energy

Olduvai
Click on image to purchase

Olduvai III: Catacylsm
Click on image to purchase

Post categories

Post Archives by Category

Wind farm blades damaged after just a few years at sea — hundreds need repair

Wind farm blades damaged after just a few years at sea — hundreds need repair

Wind farm, baltic sea/

Image of offshore wind farms.  Baltic Sea  Wikimedia | Mariusz Paździora

We are trying to collect dilute erratic energy, spread over hundreds of square kilometers in windy, salty, and wet conditions with machines that spin at 330km/hour. What could possibly go wrong?

Ørsted must repair up to 2,000 wind turbine blades because the leading edge of the blades have become worn down after just a few years at sea.

The wind turbine owner will not disclose the bill, but says that the financial significance is “small”.

h/t “Offshore wind fiasco” at GWPF      –The original story in Danish.

The cost of repair is so small they need to keep it a secret.

But it can’t be cheap. For the most part the blades need to be brought down, shipped and repaired on land.  Repairing them at sea is a rare feat.

This must be the infamous leading edge erosion.

The Offwhore Wind Industry website discussed this type of damage in 2015:

Large rotors lead to large yields, but also to lots of annoyance – at least as far as the coating is concerned. After only a few years, the protective layer that is supposed to prevent erosion is already worn out. Materials that really last for 20 years are still being worked on.

The ever larger rotor blades have led to increasing rotation speeds of the blade tips. Offshore, speeds of up to 90 m/s are now reached. This is around 330 km/h. At these speeds, raindrops and hailstones hit the coating like bullets and remove the erosion protection like a pressure washer. After that, the rain washes away the rest of the coating layers and in the worst case exposes the blade structure. The tips and the leading edges of the blades are most affected.

 

…click on the above link to read the rest of the article…

UK offshore wind capacity factors – a semi-statistical analysis

UK offshore wind capacity factors – a semi-statistical analysis

The average capacity factor at 28 operating UK offshore wind farms is 33.6% (most recent 12-month average) and 34.5% (lifetime), increasing to 36.1% and 37.5% when four demonstration projects are discarded. There is a dependence of capacity factor on age, with older farms showing capacity factors of around 30% and younger ones factors of around 40%. This is interpreted to be a result of  increased turbine sizes, with taller modern turbines accessing higher wind speeds at higher elevations. There is no evidence for significant degradation of turbine performance with time. A “generic” UK offshore wind farm coming on line in 2017 can be assumed to have a capacity factor of around 41%, although projections indicate that the turbines planned for the Hornsea II farm discussed in previous posts could have capacity factors exceeding 60%.

The data used in this post are from Energy Numbers. I have no way of verifying these data but have assumed them to be correct.

Two recent posts that attracted considerable interest, one by Euan Mearns and one by me, addressed the subject of UK offshore wind strike prices, and since strike prices are directly related to capacity factor I thought this would be an appropriate time to look into the question of what UK offshore wind farm capacity factors have been, what they are now, what we might expect them to be in the future, and in particular what are the factors that govern what the capacity factor is likely to be.

The locations of the 24 offshore wind farms used in the analysis are shown by the red boxes in Figure 1 (the four demonstration projects listed by Energy Numbers bias capacity factors low and are excluded). Ten are on the west coast of the UK and fourteen on the east. Most are close inshore. The map and the accompanying explanation are from this July 2015 UK government publication.

…click on the above link to read the rest of the article…

Olduvai IV: Courage
Click on image to read excerpts

Olduvai II: Exodus
Click on image to purchase

Click on image to purchase @ FriesenPress