Sofitel London Heathrow

Sofitel London Heathrow

An innovative HV project delivery with a nine month payback.


When the Sofitel London Heathrow hotel explored options to migrate from the Airport’s privately owned and operated High Voltage (HV) electricity system to a new supplier, significant potential energy cost reductions were identified, but only if a series of complex engineering challenges could be overcome.

Although there was a connection point to a new HV network only 200m away, a conventional ‘excavation and reinstatement’ approach to lay the cable was rejected on economic grounds. So DragonIS provided a directional drilling solution, using topographical data mapped by ground penetrating radar. This meant negotiating a host of critical – and densely located – underground services, including fuel delivery pipes, hydrant mains, fibre optic cabling, 11 and 33kV electricity cables and a gas feed.  

At the hotel site, a new intake substation was installed, along with HV switchgear, to take the feed from the DNO (SSE).


As a result of DragonIS’s innovative design and programme of works, the hotel achieved project payback in just nine months, thanks to much reduced energy costs.

A proven track record

9 months payback thanks to reduced energy costs.

ROI achieved in 9 months.

1 new intake substation installed with HV switchgear.

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