Torness nuclear power station

Comment: This vision of Scotland’s 2030 power mix is bad for industry

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Calls to increase Scotland’s reliance on renewables fail to consider important questions of operational security.

A recent report, ‘The Energy of Scotland: Heating, Moving and Powering Our Lives From Now to 2030’, published by WWF Scotland with RSPB Scotland and Friends of the Earth Scotland, envisions a region that by 2030 will “have achieved a low-cost, maximum-​benefit energy transition”. It describes Scotland “capitalising on its tremendous natural resources, generating the equivalent of 143 per cent of electricity demand from renewables, with substantial exports to the rest of the UK. An additional 7-8GW of new renewables is built, security of supply is maintained and up to 14,000 new jobs are created.”

The report wholly co-opts a 2014 study for WWF which asserted that “electricity supply in Scotland will be secure if the combined GB system is secure… With the transmission capacity to the rest of the GB currently existing or planned, there is little or no need for conventional generating capacity in Scotland to maintain security of supply.”

This vision implies England is prohibited from adopting similar decarbonisation strategies as its role is to support Scotland!

Achieving security of supply, however, first requires security of operation. The omission of defined, quantified engineering constraints from the modelling has impacted the possible set of feasible solutions, and the provided results cannot be treated as a viable vision for Scotland’s energy future.

Key constraints un-modelled include control of frequency in a scenario where up to 70 per cent of annual demand is presumed wind-generated, already of concern to National Grid as large conventional generators and their inertia are removed. Missing also is the consequential need for 1000Mvar of reactor investments in Scotland and the north of England since 2014 to prevent Scotland’s voltage from collapsing.

National Grid has also identified a need for huge ‘agility’ investment in the gas grid. “Because of variable patterns of generation and failure from wind turbines the system is having to respond... to short notice start-up of gas turbine stations to sustain our electricity supplies,” [including to Scotland] it has reported, warning that to balance the system it may have to cut gas supplies to industry this winter. Also unaddressed is loss-of-load probability (the risk of system collapse), recently calculated as having increased from four failures per 100 years to the spectre of  once every 2 years as the projected penetration of renewables grows.

Another issue is the increasing risk of failure to meet demand. NG’s 2016 Winter Outlook Report expects the reliable electricity margin to be  a maximum of 6.6 per cent, bolstered by a restart of coal-​fired units at Eggborough and the failure of the Moyle HVDC link to Northern Ireland, reducing our exports, with an “expectation” that the interconnectors with France and the Netherlands can be importing at two-thirds of capacity.

For most of the last week of November 2016, Scotland was importing electricity as calm weather coincided with the unpredicted closedown of Torness nuclear power station’s 600MW Unit 1 at the same time as the plant’s second unit was on planned reduced output for re-fuelling. Between 23 and 25 November, Scotland was importing hugely, peaking apparently at 2550MW. Even when Torness was fully back on line from the evening of 26 November, imports continued.

Existing transmission line interlinks with England can, in winter, import about 2650MW, which is the largely undeclared but prevailing reason for the construction of the £1bn HVDC Western Link from the Clyde to North Wales. This will be essential to cope with Scotland’s inability to power itself. The project website cosily and predominantly promotes the link as being necessary to cope with future levels of renewables exports.

Both Torness and the Hunterston nuclear plants will be closed by 2030 and their lifeblood lost to industry’s energy needs.

Engineering businesses are where the greatest wealth creation lies in the UK. EngineeringUK’s 2016 annual review states that the sector is responsible for over half of all UK exports. It provides 27 per cent of GDP, and pays 24 per cent of all taxes. This makes it larger than the sum of the UK financial and insurance, retail and wholesale sectors.

A Barclays Bank study shows that 59 per cent of Scottish manufacturers believe they are vulnerable to energy shortages; 46 per cent expect to be hit in the next 10 years.

Wittingly reducing the ability of our electricity grid to support our wealth generation is akin to pre-Victorian blood-letting as a useless survival strategy.

David Watson is a chartered electrical engineer who before retirement was manager of projects at Foster Wheeler Energy, based in Glasgow.

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