The London Borough of Hounslow has unveiled what it claims to be the largest PV array by a local authority, and the first to incorporate battery storage.

The borough invested £2 million to install a 1.73MW array atop Western International Market (WIM) near Heathrow with the intention of turning it into a carbon-zero attraction.

More than 6,000 LG panels were installed alongside SolarEdge inverters and DC power optimisers, ultimately charging four 60kW Tesvolt lithium ion batteries. Imtech, Sunstruck Energy and Revolution Energy Services also worked on the project.

WIM is west London’s largest wholesale market and houses around 80 fresh produce and flower retailers. As a result, the facility has an energy demand of around 3.5MWh per year to provide refrigeration.

Not only will the system save the market just under £150,000 per year in energy bills, but is also expected to contribute to around 2% of the council’s entire carbon reduction target. Total income generation, including cost savings and both generation and export feed-in tariff revenue, is expected to top £255,000 in its first year of operation.

Charles Pipe, energy manager at London Borough of Hounslow, said the installation made it the borough with the “greenest credentials in the country”.

“From the very beginning, this project has been about reducing our carbon footprint and making an investment for the future. But we have achieved so much more than that. Not only can we expect to see immediate savings on our electricity bills, but we are expecting to see a return on this investment in about five years,” Pipe said.

That payback period of five years would place the install significantly ahead of traditional installations, which have seen returns capped at around 5% under the government’s new feed-in tariff regime.

LG Solar senior sales manager Bob Mills revealed that the project was LG’s largest in Europe and said it was “testament to Britain’s continued commitment to renewables”.

“This project will deliver significant cost savings to the borough not [just] the benefits to the wider community as the team continues on its mission to become carbon-neutral. What’s more, the project has set the wheels in motion for further investment and research into the potential of battery storage, which is set to revolutionise the solar industry,” Mills added.