Renewable Energy Generation in Historic Places of Worship
Before installing a renewable energy technology in a building, all available energy efficiency measures, including low-energy lighting, heating controls and improved insulation should ideally have already been made.
There are many possibilities for low-carbon or zero-carbon energy generation. As there are also many potential pitfalls when designing and installing, it is important to find a specialist engineer used to working with historic buildings.
The installation of renewable energy equipment may have a big impact on your building’s fabric and character. It is important that you get any necessary permission, such as planning permission or listed building consent, from your denominational body and/or local authority before starting work.
Solar panels
Solar panels are an increasingly popular way for historic places of worship to produce their own electrical energy, and some have successfully sold excess energy back to the National Grid.
If your roof is highly visible, it will contribute to the setting and character of the place of worship. The installation of solar electric (photovoltaic) panels or solar slates on your building will have a material effect on its external appearance.
Minimising the visual impact of solar panels is desirable. It is often difficult and will depend on the form of the roof and location of the building. It will be easier to accommodate panels on shallow-pitched roofs largely hidden from view by parapets, or internal roof slopes not visible at ground level. If this is not possible, you may still be able to fit a ground-mounted solar collector or place equipment on another building.
Due to the high visual impact, you are very likely to need planning permission from your local authority and, where relevant, listed building consent or equivalent denominational consent.
Even when carefully designed and managed, the installation, maintenance and eventual de-commissioning of solar panels or slates is likely to cause some damage to existing historic fabric. It is important that you plan and agree in advance the means of fixing the panels to the roof and ensure that their location does not prevent rainwater disposal or maintenance work like gutter clearance.
During installation it is normal for tiles and slates to get broken – however careful the installer. You will need to think about how to repair damage or how to get replacements before undertaking any work.
Please see our pages on installing photovoltaics for more information on systems, location and planning.
Ground source heat pumps
Ground source heat pumps generally work well with underfloor heating systems. Please also see our page on heating.
In many places the ground disturbance necessary for ground source heat pumps - either a deep pit or a large, shallow area - will have serious implications for archaeological remains. This is particularly likely at sites which have been occupied for several centuries. Getting an archaeological assessment of the affected area at an early stage will inform you of any constraints.
Air source heat pumps
We tend to discourage the use of air source heat pumps on places of worship. This is due to the difficulties involved in minimising their visual impact and damage to historic fabric both inside and outside.
These systems are also usually noisy (like air conditioning units) and usually require planning permission from the local authority.
You may be able to install the external parts of a system in a church tower, if there is a silence chamber or other such space that is well-ventilated. Otherwise, heat exchange units outside the building would need to be screened or positioned in such a way that their visual impact is minimised.
The location of the internal emitter also needs careful consideration if the internal space has sensitive décor. There is a trend to site them high up like an air conditioning unit. This is not necessary and you may be able to locate them where you would expect a conventional radiator to be. The chassis can also be removed and fitted into a decorative wooden or metal case to match the interior.
With clever planning, the use of existing service runs and breaches in masonry might be possible to make the necessary pipework and ducting less obtrusive and physically damaging.
