1,800 km of new line, £20 billion of investment. The North of Scotland electricity grid is about to expand over the coming years in a way that Scotland, and the UK, has not seen since the 1960s –  in the name of meeting net zero targets, connecting up offshore wind and fighting climate change.

This is about to have a huge impact on the relatively sparsely populated regions of the Highlands, as powerlines are sent across the country and under sea, much of it for the purpose of delivering the potential 30GW of offshore wind energy that could be generated by ScotWind leases.

Scottish and Southern Electricity Networks (SSEN)  is set to build 1,800 km of new line over the coming years as part of its Pathway to 2030. This includes around 500km of new overhead line across the north of Scotland, around 1,200km of cable, some of which will connect the waters off Scotland to England, and around 100km of underground cable.

Why is it being built?

The aim of the project is to enable renewable energy to connect to our transmission network, especially the rapid expansion of offshore wind from the Scotwind leasing round.

Its purpose, said Christianna Logan, the network's transmission director of customers and stakeholders, is “to deliver an electricity transmission grid that unlocks Scotland’s potential as a clean energy powerhouse, helping to tackle the climate emergency and deliver on UK and Scottish Government energy security and net zero goals.”The Herald: SSEN's Pathway to 2030 map

A crucial element of combatting the climate crisis is the drastic cutting of greenhouse gas emissions produced by the burning of  fossil fuels and the switch to renewable is part of that.

The world is failing to decarbonise (bring down CO2) emissions quickly enough, and the rapid switch to renewables is widely regarded as the solution. While the UK has already been one of the world's fastest decarbonisers, it too is failing to bring down emissions fast enough.

Only this week, EU's Copernicus Climate Change Service announced that the world had experienced its first year-long breach of the 1.5C target to which the world is trying to hold. 

How much is the grid work in the north of Scotland going to cost?

Overall SSEN Transmission is investing £20bn in infrastructure projects. £17bn of this covers its ‘Pathway to 2030’ investment programme. There is also £3bn invested in the Skye, Argyll and Orkney reinforcement projects that are being delivered as part of Ofgem’s Large Onshore Transmission Investment uncertainty mechanism.

What type of new powerlines will be built?

Some are subsea. These include two 2GW high-voltage direct current links from Peterhead to England, known as Eastern Green Link 2 and Eastern Green Link 3. There is a further 2GW subsea link from Spittal in Caithness to Peterhead. A 1.8GW subsea cable will link Arnish on the Western Isles to the Beauly area near Inverness, known as the Western Isles HVDC Link. Orkney is also to be connected to Caithness via subsea cable.

But there are also new onshore lines, including three new 400kV onshore reinforcements; between Beauly, Blackhillock, New Deer and Peterhead; between Beauly, Loch Buidhe and Spittal; and between Kintore, Tealing and Westfield. There are also various reinforcements, line replacements and new lines between Skye and Fort Augustus and in Argyll

Does this mean more and bigger pylons?

It does in some parts of the country. Some of these pylons are set to be 57m high, and many residents are deeply upset. One group, Communities B5 Power Companies, has launched a campaign to fight them off.

The Herald:

READ MORE: Beauly pylons 'will be a scar on Highlands'

Is SSEN offering any compensation or community benefits?

Following the recent UK Government community benefit announcement, SSEN Transmission expects over £100m of wider community benefit funding to be available to local communities across the north of Scotland.

It also has plans to contribute to the development of 200 properties across the north of Scotland, which following completion of the projects, will support local housing requirements.

The UK government has also promised compensation in terms of money off energy bills for those living close to new overhead lines.

What about employment and economic benefits?

SSEN has promised jobs for the region. “Our projects create huge economic opportunity for the north of Scotland,” said Christianna Logan, the network's transmission director of customers and stakeholders, “supporting 20,000 jobs across the UK, 9,000 of which will be in Scotland and an estimated £6bn in added value to the UK economy – with us actively recruiting 400 new green jobs across our team in the next year alone.”

It’s not just new powerlines, though is it? It’s other infrastructure

Yes, there are, for instance, six new substations planned, one of which,at Beauly is predicted to be the size of over 30 football pitches.

Why do we need substations?

Substations contain specialist equipment required to convert or ‘switch’ the voltage of electricity so it can be transmitted across the country to where it is needed, but existing substations do not have enough capacity to support the increase in electricity.

Will any of this help bring down consumer electricity bills? Or will it raise them?

The price of gas is still having a huge impact on electricity bills – this is because, under the ‘marginal cost pricing system’, the wholesale price of electricity is set by the most expensive method needed to meet demand.

The investments made by SSEN – that £20 billion - are ultimately paid for by electricity consumers across Great Britain and the network has a duty to ensure its investments are economical, balancing the cost against environmental, technical, and societal factors.

There are some predicted figures out there of what the difference grid structure may make. Ofgem has said: “Our updated analysis suggests that, if all  Accelerated Strategic Transmission Investment projects are delivered by their optimal delivery dates, we expect consumers will see a net benefit of up to £2.1bn in terms of reduced constraint costs and carbon savings. However, this consumer benefit is contingent upon timely project delivery.”

A report by the climate think tank Ember, titled Cutting the bills: UK households profit from clean power states that “investments in the grid increase network costs, but this is outweighed by the wholesale cost decrease" that would happen with a shift to cheap renewables.

It predicted that deployment of renewables at speed would bring annual average household bill a saving of £300 in 2030 compared to today.

The Herald: The latest government auction failed to attract a single bid from the offshore wind industry

READ MORE: Offshore wind fears of 'further delays' on grid connection

 

Does this mean that a lot of the hard work of decarbonising the wider UK economy is being done in the Highlands? 

Yes According to the Climate Change Committee, the independent body that advises UK governments on emissions targets, the north of Scotland transmission network is set to provide around 10% of the UK’s total carbon reduction required to deliver 2050 net zero targets. 

Why not just subsea or underground all the cabling? 

The chief answer to this is cost. Overhead lines can carry roughly three times more power than subsea cables, making them more efficient and cost-effective for energy bills. They are also much cheaper than underground cables, which cost between four and eight times that of overhead powerlines. According to a London School of Economics'  blog “the direct construction cost difference is... around £8-20 million per km”.  

However, some critics point out that the threat to overhead powerlines from climate-related storms, is greater than that to underground cables.  

SSEN notes that onshore reinforcements help support local electricity needs and “improve the network’s reliability” across northern Scotland. 

SSEN doesn’t cover all of Scotland – where are the other new powerlines? 

Scotland has a second electricity netwrk, Scottish Power Energy Networks (SPEN) which chiefly covers the south of the country, which also has its own programme of extensions and reinforcements. Among these is Eastern Green Link, a subsea transmission cable, stretching Torness in East Lothian to Hawthorn Pit in County Durham, England and Eastern Green Link 4 which will create marine cables from Fife, Scotland to south Lincolnshire in England. There are also connections projects in Dumfries and Galloway, Ayrshire and South Lanarkshire. 

Is Scotland already producing more renewables energy than it needs?

In 2022 Scottish renewables alone, for the first time, generated more power than the country used. The 30GW potential from ScotWind would far outstrip what is predicted for use within Scotland. 

 

What does this mean in terms of contribution to the National Grid?

The daily percentage that is renewables on our grid varies wildly according to when the wind blows. Currently, National Grid ESO is posting the energy make-up on X  (formerly twitter), daily. Its latest figures on energy sources used said. “On Friday #wind generated 47.3% of GB electricity, more than gas 18.8%, nuclear 10.9%, imports 10.5%, biomass 7.2%, hydro 2.6%, coal 1.6%, solar 1.1%, other 0.0% *excl. non-renewable distributed generation”

For the first six days of  February the map it publishes rated the carbon intensity of the electricty consumed in the Highlands as zero - though that has since ramped up to over 100. This is because when renewables drop, Peterhead power station fires up, burning gas. The south of England was bringing in figures over 200 on some of the days the Highlands rated as zero.