Solar panels and smart batteries have powered a three-bedroom house in Portsmouth from March to September, without using any electricity from the grid.
The Port-Eco House is a property at the University of Portsmouth used for research into the energy efficiency and building performance of houses.
The installation of solar photovoltaic panels, a smart Tesla Powerwall battery and energy monitoring systems was part of SOLARISE, a €4.18m European project to accelerate the use of solar energy and to work out sustainable energy solutions for buildings.
Professor of Power Systems Engineering, Victor Becerra, said: "The house didn't need to import from the grid a single kilowatt-hour of electricity during the spring and summer months of 2022, which means with such high energy prices at the moment, this translates into significant savings.
"The upfront costs of installing solar panels and batteries into a house can be expensive, but the work on this project shows that the investment can be returned within approximately 10 years.
"The payback period has shortened significantly since the start of the energy crisis in 2021. With the combination of appropriately sized solar photovoltaic panels and battery storage, a family would have to pay very little for consumed electricity for half the year."
Solar Living Lab at the University of Portsmouth 1
Three Tesla Powerwall batteries were also fitted at the University's £12m Future Technology Centre (FTC), a facility for engineering students and staff to explore today's new and emerging technologies.
The four-storey building - already equipped with rooftop solar panels and photovoltaic windows - has been solely powered by batteries when fully charged after a sunny day, for up to four hours a day during the summer months.
Professor Becerra added: "As technology develops, batteries will become safer and cheaper. They used to be very expensive but they're expected to become more affordable and people are already starting to install them in their homes as energy prices rise.
"The combination of locally installed renewable energy and battery storage not only helps the property owners make the most of the renewable energy produced but also opens the possibility to participate in new time-of-use and export tariffs that maximise the benefits of their investment.
"Smart batteries also offer the possibility of providing backup electricity to the building in case of power outages affecting the grid, so that the electricity service can remain uninterrupted within the building, and they can even proactively charge when a storm is predicted in the area."
With the combination of appropriately sized solar photovoltaic panels and battery storage, a family would have to pay very little for consumed electricity for half the year.
Victor Becerra, Professor of Power Systems Engineering
Professor Becerra explained that the reduction of carbon emissions is significant and has a positive impact on the environment, even after considering the carbon footprint associated with the components used, such as the solar panels, inverter and batteries.
He said: "In the case of the Port-Eco house, our modelling indicates that the system is predicted to become carbon neutral after approximately five years and to produce net CO2 savings from then on. Over 20 years, this will be roughly equivalent to the CO2 absorption of 62 fully-grown trees.
"Our work on the SOLARISE project shows just how efficient and effective combining solar panels and battery storage can be. The Port-Eco house has an electricity demand similar to a typical three-bedroom home in the UK. Our work has demonstrated the benefits and opportunities that investing in solar photovoltaic and battery storage technology can bring to a household and the positive impact of residential solar photovoltaic energy on the environment.
"The FTC is a large building with lighting, computers and workshop machinery to power, so using photovoltaic and battery storage technologies fits well with the University's ambition to become a climate-positive institution by 2030."
Professor Becerra and colleagues have published Solar Energy Engineering and Applications, a book on the SOLARISE project, which covers key aspects of solar energy from a practical engineering perspective.
SOLARISE was funded by Interreg 2 Seas and the European Regional Development Fund.
