HOME ENERGY NETWORKS | ELECTRIC VEHICLES PLUGGING IN NUMBERS Plugging an electric vehicle into a home energy network could save homeowners 300 a year, according to a new study by the University of Salford in collaboration with Honda and two energy firms. Phil Lattimore looks at the challenge of integrating cars with all-electric homes A s the conversation grows around the sustainable built environment, electric vehicles (EVs), low carbon technology and smart grid solutions, a recent research project has focused on the potential benefits of integrating EVs with batteries and renewables in the home. With 34 million EVs expected to be on UK roads by 2040, the impact of the transition to electric transport is likely to have a significant impact on the electricity sector, both on the demand and supply sides with batteries in EVs not only demanding more energy but also offering the potential to offer more flexibility to the Grid for energy storage. The Home as a Virtual Energy Network (Haven) feasibility study a collaboration between the University of Salford, Honda Motor Europe, Good Energy and Upside Energy examined how much value vehicleto-grid (V2G) and vehicle-to-home (V2H) enabled electric vehicles can add in the context of domestic home energy networks. The study found that EV drivers operating a full energy network could expect to save around 300. This can be done by using storage such as home batteries and smart hot water tanks to maximise selfconsumption of solar photovoltaic (PV) power generation and by sharing electricity to and from the grid in an efficient way. However, it also found that there remained issues with coordination and integration of controls to optimise such systems using multiple assets. It also highlighted the need for hardware costs to fall to encourage investment in these solutions. Background Funded by innovation agency Innovate UK, the exploratory study was attempting to determine the potential for V2G in the UK domestic market. The researchers adopted a dual approach to assessing the value of V2G and V2H systems, through modelling and real-world testing. In-depth modelling was carried out by two Haven study partners digital energy management solutions firm Upside Energy and renewable electricity supplier Good Energy, which developed modelling approaches and assumptions independently. This enabled the study to remove (or identify) any bias and allow comparison between independent models. Real-world ground truthing of the models was carried out at the universitys Salford Energy House (SEH) testing facility a Victorianstyle two-bedroom terrace house built inside an environmental INSTALLED TECHNOLOGY The equipment installed in the Salford Energy House for the Haven project: Tesla Powerwall 2 (13.5kWh) Honda Power Manager V2G enabled EV charger Nissan Leaf (40kWh) Mixergy hot water tank (180L) Nibe air source heat pump (VMM 320) 36 January 2020 www.cibsejournal.com CIBSE Jan20 pp36-38 Electric vehicle.indd 36 20/12/2019 15:27