Broken power line between Ireland and Britain to spark electricity bills rise
Electricity customers will be hit with higher bills after a contractor put a €570m high-voltage power line between Ireland and Britain out of commission for the next five months.
National grid operator EirGrid said wind farms will be told to stop producing electricity at certain times as the power cannot be exported to Britain.
This will result in the owners being compensated, with the bill being picked up by consumers.
The East West Interconnector (EWIC) is a 500-megawatt link between the electricity transmission grids of Ireland and Britain.
It runs between Meath and the west coast of Wales, and opened in 2012. EirGrid said it would be out of commission due to a fault that occurred on September 8 during annual maintenance works at the convertor station in Meath.
The maintenance was carried out by a contractor named ABB, it said, and damage was caused to equipment at the converter station which must now be replaced.
"The equipment must be manufactured, delivered, installed and then tested," EirGrid said. "ABB estimates a return to service by the end of February 2017."
While the interconnector plays an important role in transferring power to and from Britain, the grid operator said there were no implications for supply to individual homes in Ireland over the winter. But it admitted that wind farms would be affected, as power could not be transmitted to Britain at certain times due to a lack of capacity.
Currently, wind power is exported through the East-West Interconnector or the Moyle Interconnector between Northern Ireland and Britain, which also has 500MW of capacity.
However, a problem will occur if more than 500MW needs to be exported at a given time.
This can happen when wind conditions are good, and system data from EirGrid shows this is not an uncommon occurrence.
An EirGrid spokesman said: "EirGrid plans to export wind power through Northern Ireland and into Scotland until the interconnector is repaired, but there may not be sufficient capacity. This means that wind farms will be told to power down, and they will have to be compensated.
"The costs will be borne by consumers. We are going into winter when (domestic) demand increases significantly, so we would typically export less."
The costs will be paid through levies imposed by the Commission for Energy Regulation. It is understood that not all wind farms are entitled to compensation, but that larger facilities are most likely to have the so-called "constraint payments" included in their contracts with EirGrid. These allow for compensation to be paid if ordered to power down or off.
The amount likely to be paid will depend on how often the farms are told to reduce output.
The compensation will be based on the market price per megawatt of power produced, which is currently at around €50. If an operator could not transmit 100MW, they would be entitled to €5,000. "There is no doubt that at some stage over the coming months we will have to curtail," a source said.
It is not clear why the contractor involved, ABB, will not bear any of the costs.