RENEWABLE energy projects in the islands and north of Scotland could be hampered by charges they must pay to use the national grid, according to a new report.

Costs for accessing the network have traditionally been based on a model that rewards generators for being close to centres of demand, with those on the margins paying more.

This may have worked during the era of coal-fired power stations, but it fails to reflect the reality of a low-carbon system using our best renewable resources, which are often removed from large population centres.

Consultants at Cornwall Insight have said the reasons behind the popularity of the Highlands and Islands among renewable companies – cheaper land and a more favourable planning environment than England – could dampen enthusiasm.

James Brabben, from Cornwall Insight, said: “The significant amounts of generation in Northern Scotland are located away from areas of demand further south.

“This contributed to a much higher Transmission Network Use of System (TNUoS) bill for projects … As an example, the TNUoS charge for a typical intermittent renewable generator in zone 1 in North Scotland for 2019-20 is £19.03/kW, compared to -£2.50kW (negative) in Essex and Kent.

“Currently, the more wind added to the system located further away from demand, the higher the cost of constraint payments to help balance this. This is reflected in Balancing Service Use of System (BSUoS) charges – which recover the cost of system balancing . This has been rising in recent years, currently sitting close to £3/MWh as a monthly average.

“BSUoS has also impacted embedded generators in Northern Scotland, where the large difference between generation levels and demand at the distribution level Grid Supply Points (GSPs) sees BSUoS often ‘flip’ to become a charge for generators located in GSPs where embedded generation is greater than demand.

“Our calculations show that on average, embedded onshore wind generators in Northern Scotland have seen BSUoS go from a small

net positive embedded benefit of £0.10/MWh for May 2018 to a near £4.0/MWh charge by March 2019.”

Hannah Smith, senior policy manager for Scottish Renewables, said Scotland’s energy system had to be rapidly decarbonised to meet our net-zero climate ambitions and “maximise our enviable renewable energy resources”.

She added: “This huge transformation requires a rethink of what are often outdated forms of system regulation. Making sure grid charges don’t penalise renewables is common sense.”