A principal mechanism for achieving the policy goal of the reduction of greenhouse gas emissions is the widespread electrification of transport and heating coupled with the parallel de-carbonization of electricity generation. This requires a major expansion of renewable generation (principally wind) together with new nuclear and clean fossil. This paper reviews both the policy position within the UK and the implications for system balancing that large-scale intermittent generation, such as wind, presents to the System Operator (SO). One proposal for helping to maintain system balance is the use of Demand Response (DR) by the SO. It is by no means clear whether the existing industrial structure can provide the right incentives for the realization of significant DR capacity. This paper presents a method of classifying barriers and describes experience in developing a Systems Engineering methodology, using the Systems Modeling Language (SysML), as an approach to modeling the structural and operational aspects of the British system with the objective of understanding barriers to the implementation of DR.