Devolution has played a significant role in the expansion of green energy, with Scotland leading the way, a new report has found.
A two-year study looked at how the development of wind, wave, solar and biomass energy had been affected by the establishment of the Scottish Parliament and the other devolved administrations in Northern Ireland and Wales.
Staff at Aberdeen University and the city's Robert Gordon University were involved in the research, along with colleagues from Cardiff University, Queens University Belfast and Birmingham University
Dr Richard Cowell, the principal investigator for the study, said the amount of power generated by renewable energy had "expanded most significantly" since 2002-03.
Dr Cowell, from Cardiff University, added: "We can point to a range of actions by the devolved governments - especially Scotland - that have shown significant support to renewable energy in the UK.
"The Scottish Government has led in using its powers to give greater support to wave and tidal power technologies while Northern Ireland has used their powers - greater than Scotland's - to facilitate small-scale renewables and bio-fuel processes."
The report argued that "Scotland could be considered a leader in renewable energy development within the UK". In 2011, renewable energy projects north of the border generated almost 14,000 Gigawatt hours (GWh) - with electricity from wind contributing just over half of that.
But Wales generated just over two GWh of renewable energy, while Northern Ireland produced under 1 GWh of energy from green sources.
Scottish Energy Minister Fergus Ewing said: "This report underlines the importance of the flexibility which Scotland has over energy policy, and the effective use to which that flexibility has been put since devolution.
"Successive Scottish governments have taken distinct approaches where necessary - these have built upon the advantages presented by our huge renewable resource and helped Scotland establish itself as a hub for investment and a byword for emerging renewable technologies."