Hadyard Hill has to constrain power output

The Hadyard Hill wind farm near Dailly was closed down for a period earlier this month.

However, the National Grid says this was essential in order to rebalance the network system during a period of high demand.

Questions still remain about how much this switch-off cost the taxpayer, with rumours suggesting it could have been as high as £250,000.

The site, which hosts 52 wind turbines, closed its operations for spells on the first weekend in August.

This was confirmed by the operators of the farm, Scottish and Southern Energy Generation Ltd.

A spokesperson for SSE said: “We would always prefer our wind farms to generate clean, renewable electricity when­ever they are able to, but we also recognise the job that National Grid has to do in terms of balancing the electricity grid to cope with peaks in supply and demand. As part of this activity, National Grid asked SSE to constrain generation at Hadyard Hill wind farm for periods on August 2 and 3.”

When the Gazette spoke to the National Grid, it explained how the grid needs to be balanced properly at times of high demand, a period summer falls into.

A spokesperson explained: “The current constraints on the system are a result of planned summer maintenance to upgrade and strengthen the system, and high winds.

“While we do work that will increase our capacity and ability to transport more energy we do need to take some parts of the network out of service and that will, in turn, lead to some constraints in the interim.

“National Grid is the transmission owner and operator, and so our role is to transport energy, although we do not choose the types of generation that provide this energy. That is for the market and government to decide, so it may be wind, coal, gas, nuclear for example.

“It is, however, also part of our role to balance the system and we have been doing this for many years. One of the options available to us is to use constraints.

“We can ask a generator, of any type – so not only wind generation – to come off or onto the grid. In some instances, it is most cost-effective to constrain wind.”

The National Grid, which doesn’t own the Scottish network, says it wants to keep costs down and SSE were refunded for loss of revenue.

“We are incentivised to keep costs down and constraint costs have fallen in the past year 
owing to the amount of investment made to reinforce the network.”

The SSE spokeperson said: “As is the case for any generator asked to curtail their generation, SSE received a payment to compensate for the revenue it lost.”