Impact of Microgeneration Systems on the Low-Voltage Electricity Grid A Report of Annex 54 “Integration of Micro-Generation and Related Energy Technologies in Buildings”

The primary function of Annex 54 is the analysis of microgeneration performance in buildings. Within the context of Annex 54, the term ‘microgeneration’ relates to a broad range of low-carbon technologies that can provide heating, cooling and/or power to buildings and communities. These include fuel cells and engine-based polygeneration systems, heat pumps, PV, micro wind power and biomass. Microgeneration technologies can be deployed individually or in combination (so-called hybrid systems).Whilst the primary use of microgeneration is to service the energy demands of a building or a community, microgeneration technologies could also play a role in wider energy networks such as communal heating schemes or (more typically) local electrical networks. However, the widespread participation of microgeneration in an energy network presupposes that those networks have evolved to accommodate and best utilise the microgeneration resources. Currently, this is rarely the case and microgeneration technologies tend to be connected piecemeal to existing networks, which have been designed to transport power, in one direction, from large central generators to the end user at the end of the network.The role of this report is to set the operation of microgeneration in buildings within this wider operational context. The report therefore focuses on connection into electrical networks and develops two main themes. First, the impact of microgeneration on existing electrical systems is explored. Second, the report looks ahead as to how microgeneration could be best utilised in energy networks – this will encompass approaches to control, related technologies such as energy storage (including hybrid vehicles) and demand-side control.The report draws on studies undertaken by Annex 54 partner organizations, papers presented at recent Microgen conferences [1,2] – organized by Annex members – and work done within the Highly Distributed Energy Futures (HIDEF, 2013) consortium, a group of University partners who were the UK representatives on the Annex.