Over the last few days REF has been delving into the wind constraint payments data to assist an investigation by the Scotsman newspaper into ongoing problems with the Western Link HVDC Interconnector, a 2.2 GW, £1 billion subsea cable from Hunterston to Deeside expressly built to carry Scottish renewable electricity to English and Welsh consumers.
The Western Link was expected to be ready in late 2015, but did not go live until December 2017, and only then at half capacity. It immediately experienced problems, undergoing repairs in early 2018 in preparation for full commissioning in June. However, the link tripped as soon as it was turned on after the repairs. It remains out of service, and is not now expected to try for full operation until September 2018, according to an update posted on the Western Link website.
The commercial pressures on the partners in the project, Scottish Power Transmission and National Grid, are very considerable, since Ofgem has reportedly not permitted any payments during the over-run period. What is in effect a 2.5 year delay is a serious matter for a £1 billion investment. We imagine that Western Link will try for an earlier recommissioning if at all possible.
Interestingly, in response to the Scotsman’s questioning Western Link revealed, for the first time as far as we know, that the current problem is in Liverpool Bay, so presumably subsea. The bay is shallow and should not be too difficult a place in which to work, though it is littered with wrecks, mostly shipping sunk by enemy action during the two world wars. It would be interesting to know precisely what the problem is and why SPT and NG, hardly amateurs in this field, are having such difficulty in getting the link to work.
Meanwhile, constraint payments to wind continue apace. Of course, that may actually be a blessing in disguise, since it may well be true that constraining wind off is cheaper than paying for the grid to carry the excess energy away. The Western Link is likely to cost consumers about 5 per cent of the capex per year (roughly £50 million) for the approximately 30 year life of the asset.
Of course, the consumer would have been best served if the overbuild of wind power in Scotland had been avoided in the first place.