Last month Gloucestershire based Mypower began the historic installation of 150 solar panels on the Nave roof of the 1,000 year old Gloucester Cathedral. It is the building of its type in the world to have Solar PV.
The 38kw solar array will help the cathedral cut its electricity bills by 25 per cent which is about the same amount of power used by 7 family houses. This solar PV is a small but hugely important part of Project Pilgrim at Gloucester Cathedral which is a ten-year programme developing the cathedral and its grounds.
The solar PV system will help the Church of England achieve is ambitious “Shrinking the Footprint” campaign which aims to reduce its carbon emissions by 80 per cent by 2050.
The inaugural panel was laid by the Reverend Canon Celia Thomson on the lead roof of the Nave.
The Reverend Canon Celia Thomson said: “The installation of solar panels on this remarkable building is a historic moment. We are thrilled that our vision to become a greener Cathedral is being fulfilled and proud to make a valuable contribution to the Church of England’s shrinking the Footprint campaign.”
Being a Grade I listed building, it is important that the solar panels are virtually invisible to the surrounding area. The south facing Nave roof is 30 metres above the ground and is the ideal position as the parapet wall crenellations and pinnacles hide the panels from ground view.
However the height of the wall means during the winter months there will be some shading on the panels which would reduce output potential. With the help of high performance REC BLK2 solar panels and SolarEdge inverters with optimisers the shading impact is reduced as much as possible.
A unique non-penetrating fixing system was designed specially for the cathedral. This meant no holes were made or fixings attached to the existing lead roof leaving the roof completely uncompromised.
The solar PV project has been 3 years in the making with extensive discussions on how best to apply a 21st century renewable energy solution to this 11th century building.
Mypower’s managing partner Ben Harrison said:
“It’s been fantastic to be involved in an important project like this which you can really put your heart and soul into and do the best possible job for the client – we’ve gained a huge amount of satisfaction from that.
“The historic nature of the building means we have encountered various issues to resolve but nothing that the team can’t handle.
“All roofs will sag a bit over time but particularly when there’s lead, which expands and contracts with changes in temperature and alters how it sits on the building, so that was one issue to which we had to attend.
“With a modern build, you can work to a drawing and know exactly how it’s going to be, but with a 1,000-year-old building like the Cathedral you find twists and turns on the roof and undulations where it’s sagged over the years.
“At times it’s been extremely tight in terms of manoeuvrability around parts of the site, particularly when the work required us to work just inches away from centuries-old gargoyles, but we put strategies and measures in place to protect the building from any damage.
“We’ve been working hard as a team, alongside the Cathedral team, including their architect and structural engineers, ensuring that everything is completed to the highest quality and that the work is checked and re-checked.”
Mypower will finish installing the solar panels in December ready for the big switch on and blessing during Evensong.