As an organisation we are serious about our green credentials and the impact of our carbon footprint – not always easy in an ancient building and compromises inevitably have to be made. But we do what we can, where we can, and are constantly looking at ways of improving our energy efficiency. Our Stonemasons’ workshop in Broad Oak, Canterbury has just had solar panels installed.
For all the techies out there, our PV Solar panels are a 15kWp system, estimated to produce 12,876kWh/a in the first year, which offsets 6.8Tonnes of CO2 (further technical specifications at the end of this document) but in layman’s terms this means that on a good summer’s day, the solar panels should provide enough power for two-thirds of the electricity required to run the huge 25kW saw the workshop uses or enough energy to power the lights 15 times over!
Hot water at the workshop is already heated free of charge by Viridor, the waste management company situated next door to the workshop which harnesses Energy from Waste (EfW) generating both electricity and useable heat in the form of steam or hot water while safely treating non-recyclable residual wastes. EfW is a safe, proven and robust form of resource recovery and is complimentary to high levels of recycling. By producing renewable energy it can help deliver a reduced carbon footprint and improve resource efficiency.
The bottom ash that remains after combustion in EfW plants can also be recycled as secondary aggregate for use in construction and engineering meaning that the waste is reduced even further.
So, the Stonemasons’ workshop is a fine example of our green credentials, as is the Cathedral Lodge which has reduced its energy usage by more than 25% by replacing all its traditional 50 watt down-lighters with new 4 watt LED equivalents. The Lodge carried out a review of waste procedures and has also managed to reduce food waste going to landfill by over 50% while the introduction of PIR sensors in the public toilets has resulted in a saving of approximately 200,000 litres of water per annum.
Within the Precincts, the use of low energy lighting is used wherever possible and the installation of a new low energy lighting system in the Cloister, which is not only pleasing on the eye but helps tick our green boxes too, is nearing completion. The recent refurbishment of the Howley-Harrison and the Wolfson libraries provided the opportunity to incorporate new insulation to the roof, and floor which will also have a profound impact on reducing energy waste.
The Cathedral itself brings the most challenges in terms of balancing the needs of an ancient and historic building and incorporating modern technologies and we are currently in the process of researching a new, low energy lighting system. Two systems have been demonstrated thus far but neither has yet been approved by the Cathedrals’ Fabric Commission for England (CFCE) and so the quest for greener lighting continues. The heating system however now has a super-efficient control to regulate the temperature and cut wastage.
We are committed to becoming a green organisation and staff are urged not to print material unless absolutely necessary; not to leave equipment on standby and also to turn off overhead lights if not needed. Every little action we make as individuals can add up to a huge difference when we put them all together.
Technical information on PV Panels:
The PV Solar panels installed at the Broad Oak Workshop are a 15kWp system, estimated to produce 12,876kWh/a in the first year, which offsets 6.8Tonnes of CO2 The modules are 15.2% efficient at standard test conditions which mean they transfer 15% of the sun’s energy into electricity. On a bright summer’s day, the sun has an irradiation of 1000W/m2, with 15.2% efficiency so the PV system will transfer this into 152W/m2 electricity. The system installed on the Stonemasons’ workshop covers 99m2 of roof, creating 15kW of power.
The inverter is 98.1% efficient, so of this 15kW of electricity coming down, 14.7kW will be turned into usable electricity.
The system is designed to be 80% efficient after 25 years (according to MCS standards), so considering 25 years to be the life of the system, then the system is estimated to produce 287,328kWh, which offsets 152Tonnes of CO2.