We recently explored the benefits solar panels can bring to a business’ bottom line and reputation. Here, we take a closer look at just one of many success stories: local company G’s Growers, whose sizeable rooftop installation is blazing a trail for larger projects across the country
Cambridgeshire-based G’s Growers has been growing high-quality vegetables for more than six decades. Key to satisfying demand is the company’s cold store at Ramsey, which ensures produce is held at the optimum conditions necessary to guarantee freshness and longevity. Cold stores use a lot of energy – an awful lot! So G’s Growers are always seeking new ways to up efficiencies or drive down costs.
For operations manager Kieren Drane, turning to rooftop solar photovoltaics (PV) made complete sense: ‘We were looking at ways to both improve sustainability and save costs. Incorporating solar at our cold store was an ideal application for solar PV: the store was a high energy user, particularly in the summer, and had a large roof.’
The rooftop installation couldn’t be more suited to the site’s electricity demand profile. The cold store’s demand is highest when temperatures outside are highest – on sunny days when the panels are at their most productive. In fact, the site’s enormous energy demand means that none of the electricity is exported to the grid. ‘It is all used on site, accounting for between 16% and 20% of the site’s consumption, averaging at 18%,’ explains Kieren.
This ideal scenario – high on-site energy demand – means a handsome return for the company’s £200k investment. The 239 kWp installation brings scales of economy that yield a return on capital of 19%, which means a payback of little more than five years. If this economic return wasn’t compelling enough, the PV panels will continue generating clean, silent energy for a further 20 years, bringing in an index-linked return via the Feed-in Tariff of around 11p per kWh. ‘The subsidies certainly helped make the business case for the application, providing an additional stimulus to make the investment,’ says Kieren. The fact that none of the electricity is exported has undoubtedly helped to boost returns, displacing every last possible kWh of imported electricity.
G’s Growers has a strong sustainability agenda, having implemented energy efficiency and renewable energy measures for some time. The company has achieved ISO14001 accreditation and in 2013 won the prestigious Marks and Spencer Plan A environment award. Core to the company’s efforts in this area is a commitment to a 30% reduction in carbon emissions by the end of the decade. It’s an ambitious target, but the panels have propelled G’s past the halfway mark; the company is planning an additional 240 kWp installation on an adjoining building, which should ensure the target is met. Peterborough-based Lark Energy Commercial was responsible for the project’s design and installation. Managing director Jonathan Selwyn is particularly pleased with the site’s performance: ‘It’s a perfect example of how solar can bring clean power to an energy intensive site. The result for G’s Growers is savings on both energy bills and carbon emissions.’
While the business case was a given, in practice Lark Energy had to work creatively to make the leap from drawing board to rooftop. Despite the fact that all electricity generated was to be used on site, the mere fact it could be exported to the grid proved a source of concern for UK Power Networks, the region’s distribution network operator (DNO). The problem has its roots in the way the UK’s electricity system was conceived – built around large centralised power stations, sending power across the country along high voltage networks terminating in large regional substations. Customers are then fed power from the substations through lower voltage local networks.
Renewable energy is challenging the conventional system by generating electricity in smaller, local power stations which then require power to travel in the opposite direction through the transmission lines. For Jonathan and his team this meant convincing UK Power Networks that the project wouldn’t impact the already overloaded local grid. ‘We got around the problem by agreeing to install remote management hardware, which the DNO can use to turn off the system’s export capacity in an emergency,’ explains Jonathan. This was the first system of its kind in the country and was far preferable to the alternative: replacing the existing substations to enable connection at a cost of nearly £70,000.
Once installed, it took many weeks for the monitoring and management system to be perfected so that all data could be accessed remotely in real time and connection could be controlled by UK Power Networks. It is now, however, fully functioning, while the electricity generated by the 1,000 PV panels continue to lower the cold store’s energy bills and carbon emissions. The PV system at G’s Growers will feed into research that will be shared with all DNOs facing the same challenge of connecting high levels of renewable generation over the coming years. It will enable them to explore cheaper ‘interruptible’ connections using new control and monitoring smart technologies to improve the use of existing networks.
Lark Energy Commercial was delighted to work with G’s on this innovative project and hopes it can be the first of many such trial projects to open up the electricity network to further renewable energy generation. Meanwhile Lark Energy continues to help companies across the region lower their carbon footprints while slashing fuel bills, making businesses stronger and more resilient in the process.
LARK ENERGY COMMERCIAL Future Business Centre, London Road, Peterborough PE2 8AL. 01733 666610, www.larkenergycommercial.co.uk