Claims that the lights will go out if Scotland does not build new nuclear power stations is ill-informed scaremongering and ignores the reality of our energy systems and markets. Such claims also downplay the success of the Scottish renewables industry, which has, so far, delivered its generation targets ahead of schedule.

As it stands, Scotland has no shortage of electricity. Each year we even manage to export almost one-fifth of our output to England and Wales. Using official and industry data, Friends of the Earth Scotland has looked at various scenarios for the future of Scotland's electricity generation up to 2025 - two years after the scheduled closure of Scotland's last nuclear station, at Torness. Even making conservative assumptions about future renewables capacity and assuming no change in the poor performance of energy-saving policies, there will be no year in which demand comes even close to exceeding supply. In all the most likely scenarios, in no foreseeable year will the margin fall below the current level of exports.

This is the result of expected developments with renewables and cleaner coal technologies.

ScottishPower's plans to renew capacity at Longannet and Cockenzie with cleaner coal technology make a big difference to the figures for generation capacity. To deliver real cuts in carbon, too, they must move rapidly to install carbon capture and storage (CCS) technology as well. The technology already exists, but urgently needs to be demonstrated commercially. Any further CCS plants constructed within the next 17 years will increase further the margin of excess capacity.

Wind power will continue to expand, but these scenarios limit it to about 20% of capacity - a level that is manageable on a national network, and that need not intrude on areas designated for valuable landscapes or wildlife. We will also see the gradual introduction of marine and other renewables, including biomass.

In the most likely scenario, renewables will reach 46% of capacity in 2020 - almost 10% behind the industry forecasts for that date, and only hit the forecast level of 55% five years later, in 2025. To put this in context, the industry met its 2010 target of 18% three years ahead of schedule, with even more capacity awaiting planning decisions.

Micro-renewables - not just rooftop turbines, but including a range of technologies - can make a small contribution, perhaps as much as 8% of Scotland's generation capacity by 2025. Alex Salmond's welcome one-million homes target might mean up to 100,000 installations a year in the 2010s - that's more slowly than Scots fitted satellite dishes, or install central heating boilers. Of course the level of generation is not the only question at issue. There are two other considerations. First, can the system meet peak demand? Secondly, will it be able to do so even with a larger share of variable or intermittent sources of power, such as wind turbines?

The first is easily answerable. As a result of accidental shutdowns, we have seen already that the Scottish electricity system can continue to meet even peak demand while neither Hunterston nor Longannet is in production. The second is more challenging, but the evidence is reassuring. Research has shown the quality of the wind resource in Scotland is the most consistent in the world. Moreover, Scotland is part of a UK grid, making the daily challenge of matching demand easier. And it is possible to manage peak demand. Simple contract revisions with major power users could slash the levels of the back-up generating capacity needed, while dynamic demand appliances, such as freezers that vary electricity consumption inversely in line with demand on the grid, are only just appearing on the market.

The challenge becomes smaller if the current executive consultation on an energy efficiency strategy leads to practical measures to begin delivering the 30% or so energy savings that are cost-effective today. This would mean that instead of efficiency simply taking the edge off growth in demand, resulting in net increases of about 0.5% a year since 2000, overall demand could be gradually reduced, cutting Scotland's consumption by about 1% a year, while saving businesses and householders money.

In all these scenarios, there is no need for nuclear new-build, or to extend the lives of Scotland's nuclear stations. New plants would be expensive white elephants.

The scheduled closure of Torness and Hunterston will not put the lights out. But the nuclear obsession gripping Whitehall puts at risk the development of sustainable low-carbon electricity to meet our climate change targets. An infatuation with nuclear is already threatening to dominate and distort investment, grid capacity, training, political attention and public will, leaving energy saving, renewables and carbon capture without the support they need. Scotland has already lost one important low carbon investment (Peterhead - in part as a result of Whitehall's nuclear obsession); it's now time to complete the devolution of energy policy so we don't lose any more.

  • Duncan McLaren is chief executive of Friends of the Earth Scotland.

The Power of Scotland report is available at www.foe-scotland.org.uk