Overhead Electrical Transmission Lines

Lord Swire Excerpts

Thursday 29th February 2024 Grand Committee

Asked by

[Lord Swire]

To ask His Majesty’s Government what assessment they have made of the advantages of burying overhead electrical transmission lines.

[Lord Swire (Con)]

My Lords, I am very pleased to open this debate and I am most grateful to noble Lords who have signed up for it. Many more have approached me elsewhere to say that they cannot be here, but they feel as strongly about it. I start by conceding that it may seem a little eccentric or self-indulgent to have a debate on this subject when so much is going wrong elsewhere in the world, but it is an incredibly important subject, and one that we need to be very aware of in terms of the implications going forward.

Let me say at the outset that I fully recognise the Government’s commitment to reach their target of net zero by 2050, and the challenges of achieving that in a difficult planning environment. They are encountering the same difficulties in reaching their housebuilding targets. Everyone—or at least most people—is signed up to the principle of more housing; the problem starts when the new housing is going to be anywhere near them. I believe that that can be overcome by good design, with houses built in the right place, and by building housing that actually enhances existing communities rather than detracting from them. Unfortunately, with powerlines, we do not seem to be faced with any such choice.

National Grid, which noble Lords will hear a lot about in the next few minutes, estimates that there are more than 22,000 transmission pylons across England and Wales, made up of 4,500 miles of overhead cables and only 900 miles of underground cables. I think that I am writing saying that, where National Grid is the distribution network operator—known in the business as the DNO—as in the Midlands and in my part of the world, the south-west, south Wales and so forth, the network is made up of a further 60,000 miles of overhead lines and 83,900 miles of underground cables. These figures are set to increase dramatically. National Grid’s “Great Grid Upgrade” includes proposals for hundreds of miles of high-voltage overhead lines right across great swathes of our countryside, all held up by pylons.

I acknowledge from the outset that overhead transmission lines are cheaper than the alternatives. The Parsons-Brinckerhoff report states that,

“overhead line (OHL) is the cheapest transmission technology for any given route length or circuit capacity, with the lifetime cost estimates varying between £2.2m and £4.2m per kilometre”.

Why we use kilometres I do not know, but we seem to from time to time. It continues by saying:

“Underground cable (UGC), direct buried, is the next cheapest technology after overhead line, for any given route length or circuit capacity. It thus also represents the least expensive underground technology, with the lifetime cost estimate varying between £10.2m and £24.1m per kilometre”.


It is precisely these figures that the Government pray in aid time and again to defend their policy. Further, in the National Policy Statement for Energy Infrastructure, EN-1 contains a

“strong presumption in favour of pylons”.

The Prime Minister has described a lack of electrical infrastructure, such as cables, pylons and substations as

“one of our biggest constraints to reaching net zero”,

and described the 14 years that it takes to get some projects under way as “unacceptable”.

We know that grid capacity has to double to transport energy from offshore wind, solar farms and other renewable sources to meet demand, which is anticipated to double by 2050. Nick Winser, the UK’s first Electricity Networks Commissioner, says that our policies are out of date, and we need £54 billion worth of new grid infrastructure by 2030.

All this has huge significance for our country, particularly our countryside. There are good and bad ways of achieving net zero, and this is a bad way. One of the main problems is the lack of joined-up, long-term thinking, not least when it comes to bringing offshore-generated electricity onshore. Can my noble friend the Minister please explain why substations are located offshore in countries such as Holland and Belgium—I understand that Denmark and Germany intend to follow suit—yet current UK policy is that instead of pooling power from the 18 or so wind farms and interconnectors in need of connection points to the UK, National Grid is offering each and every project a connection one by one? If this was not folly enough, having the substations onshore is even worse. Scottish Power wants to build, inland at Friston village near Aldeburgh in Suffolk, a substation which would be 50 feet high and cover 30 acres. Surely we can be smarter than that.

While I am on the subject of wind turbines, can the Minister confirm that they take 15 to 20 years to become carbon neutral and that the engines need replacing after 10 years?

Today, East Anglia is in the firing line. It faces the prospect of 100 miles of new pylons cutting a swathe through some of our most beautiful and historic countryside. It is tragic and, to my way of thinking, vandalism. It is true that Ofgem, through the visual impact provision, has identified £500 million to help reduce the visual impact in areas of outstanding natural beauty and national parks, and National Grid runs a landscape enhancement initiative as part of this project. But when I last looked, National Grid’s revenue was almost £5.5 billion last year, with profits up by 15% and a net profit margin of over 13%. John Pettigrew, National Grid’s chief executive, boasted:

“A record £7.7 billion has been invested in building clean, smart energy infrastructure and maintaining world class reliability across our networks”.


What about its East Anglia green initiative? It looks good because it is transporting renewable or clean energy, but at what cost? The cost is 180 kilometres of 400 kilovolt overhead cables, 50-metre-high pylons, except in Dedham Vale, where they will be buried, and a new 400 kilovolt connective station near Colchester.

What consideration has been given to alternatives, such as cable ploughing—in other words, ploughing the cable straight into the ground rather than having to dig up 120-metre-wide swathes of our countryside—or using DC instead of AC, which requires a narrower trench? What is the Minister’s view of TS Conductor’s new generation of super lightweight and super strong conductors? I think I am right in saying that the UK Government are an investor in that company. They are already installed in the US and have the great benefit of being able to transmit five to six times more power—critically, using existing infrastructure, the net gain being that fewer pylons would then be needed. This calls for more creative thinking from all those involved.

Incidentally, I wrote to the papers about the onshore distribution of electricity some ago, when I saw that the Crown Estate is proposed to gain many billions of pounds from renewable energy. It has let it be known at a very high level that it wishes the money generated from those profits to be ploughed back for the public good. What better way to spend that money than on burying all the cables that this offshore wind will generate?

The offshore distribution of electricity needs a major overhaul to meet new demand in different places. The offshore grid in the North Sea needs much better integration, which would save £2 billion and reduce overall infrastructure by 50%. We need to be more protective of our countryside, our green and pleasant land, before we wake up to find that we are too late.

The late Poet Laureate, Ted Hughes, wrote in his poem “Telegraph Wires”, which was part of his collection, Wolfwatching, about

“The Striding Steel Sentries

Marching across the land”,

describing them as “mighty metal monsters” and concluding,

“If we didn’t have them

Darkness would be our fate”.

But that was written in 1989, and the technology available to us has moved on considerably. We do not have to have mighty metal monsters marching across our land to transmit the technology; there are other ways. As the technology improves, more choice should be available to the consumer.

I simply do not understand how we can reconcile patting ourselves on the back by importing more renewable and green energy if the cost of that will be to desecrate our natural habitats and unrivalled landscapes at the same time.