Commercial solar PV developer EvoEnergy has completed the fourth largest rooftop PV system in the UK for Lyreco, a global office and workplace solutions provider, with the installation of a 3.811 MWp solar array at its national distribution centre in Telford.
The install, made up of 13,860 panels, was fitted on to the roof of the firm’s 15-acre logistics site between October and January to cut its carbon footprint and is one of only five rooftop systems in the UK to exceed a yearly output of 3.2 GWh (Watch the video here).
It was the largest rooftop PV system to be completed in the UK in 2015 and is the second largest on a single building. It was also the first in the country to use large central inverters more commonly used for solar farms, bringing ground mount centralised inverter technology to a rooftop installation for the first time.
Owned and operated through a 20-year Power Purchase Agreement by Addison Energy Limited – a company funded by Guinness Asset Management’s EIS service - the system will save Lyreco more than £53,000 a year on its energy bills, as well as cutting annual carbon emissions by 1,700 tonnes - making the whole site carbon neutral in terms of electricity usage.
Nick Dacey, logistics director for Lyreco, said: “We have a large warehouse here in Telford with a large open space on the roof and it recently became obvious that solar panel technology had reached a point where it would be economic for us to engage in that.”
EvoEnergy was awarded the contract for its innovative technical solution to Lyreco’s challenge of offsetting the environmental impact of its 55,000 sq m distribution centre and 275 delivery vehicles.
A team of 30 installers, electricians and project managers worked on-site during the installation process, working through the wettest December ever recorded in the UK. They fitted 13,860 Trina Solar 275W panels in three months onto a rooftop the size of 7.5 football pitches.
Project managers devised new rope access techniques and temporary skylight covers, alongside standard demarcation techniques, so teams could move around and work on the roof in safety. These allowed them to avoid disruption to Lyreco’s day-to-day operations while adhering to the highest health and safety standards.
James Sutton, project manager on site for EvoEnergy, said: “The install went smoothly from start to finish thanks to the hard work of our technical team and their counterparts at Lyreco and Guinness.
“It takes a huge amount of careful planning and execution to make a job this large run without any hitches. It’s been a team effort to get here; one that’s required all of our electrical, mechanical and civil engineering expertise, but now the PV is helping a global firm like Lyreco cut its costs and reduce its environmental impact.”
Expert high voltage electrical solutions were required from EvoEnergy to fit the panels to work with the 11,000v on-site power supply, which the team handled by incorporating specially-built step-down voltage regulators into the system’s design.
EvoEnergy was chosen for its willingness to take on not just the responsibility for the operation and maintenance contract of the finished array, but also the future maintenance of the roof itself too, until 2021.
Restoring the roof to the best condition possible before the PV was installed required the team to replace 50,000 of the original roof fixings, as well as repairing and treating over 10,000 linear metres of cut edge corrosion.
James Sutton said: “As it’s a funded project, we needed to deliver a turnkey installation fit for purpose for years to come. We carried out the work in seven phases, with rope-access teams working ahead of our installers to make each workspace safe beforehand.
“With similar large-scale projects to our name already, we were equipped to keep work moving on-site at a steady, continuous pace. Our technical team, meanwhile, had the forward thought to propose the use of two large ABB 1.56MW central inverters, often used in ground mount installations, mounted adjacent to the building, saving Lyreco the space of more than 100 regular string inverters.”
Dr. Malcolm King, investment manager for Guinness Asset Management, said: “We're pleased to have worked with Lyreco and EvoEnergy to complete one of the UK’s largest rooftop solar installations. This demonstrates our ongoing ability to source and deliver high quality projects for our investors.”
System in detail
● 3.811 MWp rooftop array
● 13,860 Trina Solar 275W panels
● 2 x 1.56 MW ABB central inverters
● 23,000 sqm coverage
● 1,700 tonnes of CO2 saved per year (estimated)
● Minimum of £53,000 annual saving on energy bills (estimated)