While the focus of the UK nuclear sector is on the new-build programme, recent results from EDF remind us that existing nuclear capacity is still a major player in the UK energy scene.

Their nuclear fleet is now delivering more electrical energy than at any time during the past eight years, resulting in a boost for operating profits. And with a 10-year life-extension for Dungeness B due to be finalised later this year, nuclear investments from the 1970s and 80s will still be paying dividends for many years to come.

Nowhere is the contribution of the UK nuclear fleet more apparent than in Scotland, with two reactors at Hunterson and Torness. Though a little-known fact, through these two compact plants, nuclear is the largest generator of electrical energy in Scotland by some margin, as it has been for many years. Indeed, the output from the single nuclear plant at Torness alone (9 TWh) comfortably exceeds the combined output of every wind, wave and solar generator in Scotland (8.3 TWh). This clearly illustrates the benefit of energy-dense fuels used in compact and efficient thermal plants, which can provide continuous output over a plant life of many decades.

While Scotland is pitched as the Saudi Arabia of renewable energy, it's steadfastly nuclear-powered.

In contrast, the arbitrary government target of generating the equivalent of 100% of Scotland's electrical energy consumption from diffuse and intermittent renewable resources by 2020 is perplexing. While climate change targets are mooted as one of the primary motivations, Scotland's electrical energy generation is in fact already 100% low carbon, as measured against the government's own metric.

In 2012, Scottish electrical energy consumption was 30.8 TWh, while production from our two compact nuclear plants was 17.0 TWh, all wind, wave and solar production was 8.3 TWh, hydro 4.8 TWh and other renewables 1.6 TWh.

Output from low carbon sources therefore exceeded domestic consumption, a fact that is rarely noted, or indeed celebrated by government and environmental NGOs. To do so would be to acknowledge the reality of the immense contribution of nuclear energy to Scotland's electrical energy production, and indeed its exports to the rest of the UK.

Colin McInnes is Professor of Engineering Science at the University of Strathclyde