In This Article:
SSE has added to pressure on Heathrow after confirming that key electricity supplies into the airport continued uninterrupted last week despite the fire that wiped out a nearby National Grid substation.
Two sets of cables into the airport remained “fully operational” according to SSE, which runs the networks that directly supply Heathrow and most of Hillingdon.
The revelation piles fresh pressure on the bosses of the foreign-owned airport, following a separate statement from John Pettigrew, National Grid chief executive, that Heathrow always had “enough power”.
Heathrow executives are facing calls to explain their apparent lack of preparation for fluctuations in grid supplies and consequent decision to shut down the airport.
Europe’s busiest airport closed for most of Friday following a catastrophic fire at National Grid’s North Hyde substation, Heathrow’s primary electricity source, on Thursday night.
However, Heathrow should have been able to switch supplies to two other National Grid substations in the region, at Laleham and Iver, both with feeds into Heathrow.
All three substations are shared with SSE, with National Grid bringing in high-voltage power and feeding it into transformers belonging to SSE that reduce the voltage so it can be distributed to local consumers.
For major customers like Heathrow, SSE feeds the power into another set of transformers on their sites. Heathrow then takes responsibility for its use just as householders are responsible for the wiring and consumption within their homes.
Heathrow’s apparent inability to switch supplies smoothly shut down the airport and resulted in the cancellation of 1,300 flights, ruining travel arrangements for hundreds of thousands of passengers. Compensation costs are expected to cost airlines tens of millions of pounds.
Energy experts say such power failures are a known threat and there is tried-and-tested technology to minimise the impacts.
Edward Galvin, an expert at consultancy DC Byte, said it was standard for data centres to have “failover” systems that keep their power going in the event of power cuts, either by switching them over to alternative substations or by firing up a backup generator.
This process typically takes minutes and is seamless. Heathrow insisted it needed most of Friday to recover after the airport lost power.
Mr Galvin said this indicated the airport had not invested in proper backup systems, which he suggested might cost around £50m in this case.
He added: “Fundamentally, there is no reason why Heathrow could not have the same automatic failover systems that worked perfectly for nearby data centres that were also attached to the same sub-station.