Calling time on the majestic march of the pylons

Editor

Could National Grid plans to replace pylons at UK beauty spots pave the way for a rethink on our future transmission network?

Electricity pylons are divisive things. For some, they’re an eyesore. A brutal blot on Britain’s once bucolic landscape that drives down property prices and, some allege, affects public health. Others argue that there’s something strangely majestic about their determined march across the countryside.

It probably won’t surprise anyone to learn that as well as a slew of groups campaigning for the downfall of these ubiquitous structures, there’s also a dedicated pylon fan club.

But whatever your feelings – and I have to confess that though I haven’t joined the fan club I’ve always found the sight of them vaguely stirring – one thing’s for certain. If, in some imaginary pylon-free version of the present, they were to suddenly emerge as the preferred alternative to whatever form of electricity transmission we’d hitherto relied on, the chorus of public disapproval would make local opposition to wind energy, HS2, or even a new Heathrow runway, look like a polite disagreement at a village fete.

It’s perhaps something of a moot point. Pylons are here, and form the core of the UK’s electricity distribution network. But could this week’s news that the National Grid is pushing ahead with plans to remove pylons from some of the UK’s most well-known beauty spots, pave the way for a wider rethink on what our transmission network looks like in the future.

Under the new scheme, National Grid will be spending £500 million of OFGEM funding on replacing overhead cables with underground power lines at locations in Dorset, Snowdonia, the Peak District and the New Forest. The plans will reportedly lead to the removal of a total of 45 pylons.

It’s a laudable proposal, motivated entirely by environmental and aesthetic concerns, and even the biggest pylon enthusiast would have difficulty arguing against the move enhancing the affected areas.

But could there be other advantages to going underground? And, as previously reported by The Engineer, is the technology required to do this on a wider scale still prohibitively expensive?

There are a number of underground options – including burying cables in tunnels and installing HVDC connections. However, one particularly promising  alternative is the use of gas insulated transmission lines (GIL) which encase the conductor within an insulated metallic gas filled tube and offer similar performance to overhead high voltage cables. 

The problem with GIL, as with all of the above, has been cost. But recent breakthroughs by engineers at Siemens in Germany have led to the development of (GIL) capable of carrying large amounts of energy at DC voltages, a breakthrough that many claim could help make underground cables more cost effective.

All of these options are more expensive, but as the technology improves costs will come down.  

With pressures on land use growing and the national grid planning miles of new transmission lines to cope with increased demand and output, perhaps now is the time to begin looking seriously at some of these alternatives, before the majestic march of the pylons becomes a mad stampede.