A research project to quantify the benefits of self-storage batteries is under way in 37 houses in Nottingham
What: SENSIBLE energy storage system
Where: Nottingham
Financially viable onsite energy storage has long been the missing piece in the renewable energy jigsaw. However, the rapid development of the electronic car has produced technological advances that are transferring to the built environment, making individual home storage systems increasingly commercially available.
In Nottingham, an innovative scheme aims to quantify the direct benefits of self-storage batteries on a community level. Funded by the European Union’s Horizon research and innovation programme, the project, named SENSIBLE (Storage Enabled Sustainable Energy for Buildings and Communities), will install batteries in up to 37 homes across the Meadows area of Nottingham, free of charge.
This community of homes across different tenures, types, ages and socio-economic groups will be a test bed to scientifically record and analyse the exact benefits of battery storage. More than 20 of them already have solar photovoltaic (PV) panels installed using government grants.
Along with the home storage systems, larger community batteries are also being installed in a local school and library to investigate the possibility for the community to share energy, rather than relying on the existing grid system.
The project is being led by the University of Nottingham and MOZES, the Meadows’ Community Energy Group, with the batteries installed by the charity, Nottingham Energy Partnership and T4 Sustainability, a renewable energy installer.
SENSIBLE will install batteries in up to 37 homes across the Meadows area of Nottingham, free of charge. This community will be a test bed to scientifically record and analyse the exact benefits of battery storage
Dr Lee Empringham, principal research fellow at the University of Nottingham and project lead, explains: ‘We will monitor household energy patterns for 12 months to see both what benefit there is to storing the excess and how people react to their ‘free’ electricity in the evenings. We will also research the storage of thermal energy produced using electricity from solar photovoltaic panels together with dual tariff systems to reduce the total energy costs.’
The batteries store excess solar energy from photovoltaic panels, as well as cheap off-peak electricity collected during the day, for use in the evening when home energy use is at its highest. Storing electricity onsite in this way both reduces bills for the homeowner and puts less load on the local grid.
Proving the viability of home storage systems could greatly boost the adoption of PV use in the UK, as it balances out the peaks and troughs of renewable energy generation.
Paul Chandler from T4 Sustainability, which commissioned the first system in March, says of the early results: ‘The first installation has shown that the system is working very well with over 80 per cent efficiency, meaning it can power a house overnight and offer real financial and environmental benefits.’
Power balance
The choice of equipment is determined by space requirement, accessibility and house type. Each home storage system relies on two key factors: the capacity of the battery and the rate of charge and discharge. Batteries initially being installed by T4 Sustainability have a capacity of around 6.5kWh and can a charge/discharge rate of around 2.5kW.
These batteries are connected to a charger/inverter box that regulates the amount of charge entering and leaving the battery. This is wired into the mains. An energy meter acts as a sensor, sending information to the charger/inverter box, which decides the rate of battery charge or discharge.
For example, if a house has 1kW of loads switched on and the PV is generating power of 4kW, 2.5kW will be used to charge the battery and 0.5kW exported to the grid.
As far as the battery capacity and maximum rates of charge and discharge allow, the system will act to minimise both energy export and energy import.