Divine light The Dean of Gloucester Cathedral, Stephen Lake, blesses the cathedral’s solar panels after the solar-energy firm MyPower installed them in November 2016. The array of PV panels generates just over 25% of the building’s electricity. (Courtesy: MyPower)
Topics: Alternate Energy, Applied Physics, Battery, Chemistry, Economics, Solar Power
With energy bills on the rise, plenty of people are interested in ditching the fossil fuels currently used to heat most UK homes. The question is how to make it happen, as Margaret Harris explains.
Deep beneath the flagstones of the medieval Bath Abbey church, a modern marvel with an ancient twist is silently making its presence felt. Completed in March 2021, the abbey’s heating system combines underfloor pipes with heat exchangers located seven meters below the surface. There, a drain built nearly 2000 years ago carries 1.1 million liters of 40 °C water every day from a natural hot spring into a complex of ancient Roman baths.
By tapping into this flow of warm water, the system provides enough energy to heat not only the abbey but also an adjacent row of Georgian cottages used for offices. No wonder the abbey’s rector praised it as “a sustainable solution for heating our beautiful historic church.”
But that wasn’t all. Once efforts to decarbonize the abbey’s heating were underway, officials in the £19.4m Bath Abbey Footprint project turned their attention to the building’s electricity. Like most churches, the abbey runs from east to west, giving its roof an extensive south-facing aspect. At the UK’s northerly latitudes, such roofs are bathed in sunlight for much of the day, making them ideal for solar photovoltaic (PV) panels. Gloucester Cathedral – an hour’s drive north of Bath – has already taken advantage of this favorable orientation, becoming – in 2016 – the UK’s first major ancient cathedral to have solar panels installed on its roof.
To find out if a similar set-up might be suitable at Bath Abbey, the Footprint project worked with Ph.D. students in the University of Bath-led Centre for Doctoral Training (CDT) in New and Sustainable Photovoltaics. In a feasibility study published in Energy Science & Engineering (2022 10 892), the students calculated that a well-designed array of PV panels could supply 35.7% of the abbey’s electricity, plus 4.6% that could be sold back to the grid on days when a surplus was generated. The array would pay for itself within about 13 years and generate a total profit of £139,000 ± £12,000 over its 25-year lifetime.
Home, green home: scientific solutions for cutting carbon and (maybe) saving money, Margaret Harris, Physics World