There is currently an expansion of local energy initiatives, underpinned by the desire to reduce energy-related carbon emissions and in recognition of the importance of the local arena to achieving such change. Much of the research on these initiatives has been framed by a conventional economic approach, identifying barriers, drivers and incentives to explain their emergence (or not). Here a new economic sociological approach is taken which sees markets as socio-materially constructed and points to the importance of tracing exchange flows and determining modalities of valuation for such exchanges. Artefacts or market devices are seen to play a particular role in connecting actors and technologies within coordinating institutional arrangements and offer the potential for making innovative projects conventional. These aspects are explored in four international case-studies from Wales, Sweden, Germany and USA, mapping relations, identifying exchange flows, pinpointing how artefacts coordinate and showing the multiple modalities of valuation involved in each case. Conclusions concerning the importance of negotiation against a market backdrop and rendering exchange flows more certain are drawn.