A strategic analysis methodology is presented for adaptive energy systems engineering to realize an optimal level of service in the context of a community's social, economic, and environmental position. The groundwork stage involves characterizing the social context, assessing available energy resources, identifying environmental issues, setting eco-resource limits, and quantifying socio-economic constraints for a given region. A spectrum of development options is then constructed according to the range of energy service levels identified for the sector under study. A spectrum of conceptual energy systems is generated and infrastructure investments and resource use are modeled. The outcome is a matrix of energy system investment possibilities for the range of energy demand levels reflecting the values, ideas, and expectations expressed by the community. These models are then used to assess technical feasibility and economic, environmental and social risk. The result is an easily understood graphical depiction of local aspirations, investment options, and risks which clearly differentiates development opportunities from non-viable concepts. The approach was applied to a case study on Rotuma, an isolated Pacific Island. The case study results show a clear development opportunity space for Rotuma where desired energy services are in balance with investment sources, resource availability, and environmental constraints. (C) 2009 Elsevier Ltd. All rights reserved.