Renewable energy is a growing sector as nation states aim to curtail their carbon emissions and establish a more sustainable strategy to generate energy. However, there are disputes that large scale renewable energy developments replicate corporate and centralist traditions of energy generation and fail to contribute towards community sustainability and local economies. Community Energy projects – renewable energy projects that are part or fully owned by a geographically distinct community – are seen as a means of generating energy in a way that is more sympathetic, equitable and sustainable. Unforeseen social and economic benefits accrue from community energy projects such as community cohesiveness, higher financial returns, autonomy and resilience, a sense of local pride through ownership and behavioural change through an increased understanding of sustainability issues and energy consumption. Apart from contributing to the overall production of energy from renewable sources, community energy projects also seem to have the added benefit of attaining more support within their locality. This is of crucial value when bearing in mind opposition to the development of some renewable energy projects. There are also disparities in how such projects are diffused and supported, particularly within the UK. Focusing on the sub-state nations of Scotland and Wales, this thesis looks in depth at the experiences of developing community energy in peripheral and rural Welsh and Scottish Gaelic speaking areas of both devolved countries. Through a series of in-depth, semi-structured interviews with community energy actors in four case sites across north-west Scotland and north-west Wales alongside a Delphi method questionnaire amongst specialists working in the field at sub state level, the research draws a picture of the current state of the community energy sector in both nations. The research shows that support structures in Scotland have contributed to a sense of confidence amongst communities to develop local energy generating projects. This is reflected in the number of successful Scottish community energy case sites currently operational. This confidence, at time of researching, was lacking in Wales. A clear case was made that more focus and support was needed for the niche sector to grow in Wales. It was also evident that communities viewed cultural sustainability as intrinsic to the development of their community energy projects – an added benefit that has not been accredited with the sector in any previous research.The thesis furthermore contributes to an understanding of the optimal conditions for the development of community energy projects in Wales and Scotland, how the relationship between incumbent actors and geographically peripheral communities currently operates and the unforeseen cultural benefits of such projects.