The story of Block Island caught my eye. Block Island off Rhode Island is a permanent home to 1000 residents. In the summer times, daily visitors number between 10 to 20,000. Electricity supply has been problematic with some using generators and their own wind turbines. An application by the community for a grant for an undersea cable to connect to the mainland grid was rejected. The proposed wind turbines, 5 Haliade 6MW turbines, seemed a no-brainer for most though there were those who objected to it. But this small, private wind farm went ahead and began commercial operation in 2016. But there have been problems. Within a couple of years, the undersea cable connecting to the mainland (as part of the wind farm project) became uncovered at the island end for it had only been buried in places at four-foot depth to save money. Warning flags appeared on some beaches for a while and the cable had to be reburied at the cost of $31million. This reburial also has also problems with blockages and sediment.
There is some controversy over who paid for this reburial with claims that the National Grid profited by $46million from customer surcharges for maintaining the cable. The National Grid denies this.
This June, 2021 it was noticed 4 out of 5 of the turbines had ceased operation. The community on the island struggled to get any information from the operators, the Danish-based Orsted, who claimed that the turbines were down for regular maintenance which was best performed in summer. Ignoring the fact that it is the summer when the island needs the power most, this caused a lot of frustration and the turbines were down for the best part of two months. It emerged then that stress fatigue was noted on the support structures of the “helihoist” platforms on some of GE Haliade turbines in the Merkur project in the German North Sea. Stress lines were subsequently found in Block Island’s turbines but a risk assessment has deemed them safe and repairs were also undertaken.
The Haliade turbines are the same turbines being considered for some of the Copper Coast windfarms – though likely they will be of more recent versions and of higher wattage – which will have well over 100 turbines if projected output is anything to go by.
In the end, the shutting down of the turbines caused no power interruption for the island as the cable, though still being reburied, continued to connect them to the national grid. As far as I know, the turbines are operational once again.
Previous Posts
The Winds of Change: Introduction to a Series, The Winds of Change: The Proposals, Windy Wednesday: Distance to Horizon for Dummies, Windy Wednesday: Some Windfarms
Links
https://www.blockislandtimes.com/article/national-grid-returning-finish-cable-reburial/59851
https://electrek.co/2021/08/10/egeb-us-first-offshore-wind-farm-is-currently-offline-heres-why/https://splash247.com/turbine-stress-issues-bring-merkur-offshore-wind-farm-offline/
https://www.theday.com/article/20210807/NWS05/210809578
https://www.ge.com/renewableenergy/stories/block-island-construction-process
The Mermaid's Purse 