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Churches A sunny outlook In the last of a series of three articles describing the Diocese of London’s efforts to reduce its churches’ energy use and carbon footprint, Brian Cuthbertson looks at a solar installation in an Islington church The use of PV panels was accepted at St Mary, as they occupy almost the entire roof slope, presenting a uniform appearance 2 Building Conservation Journal March-April 2012 © Brian Cuthbertson In a recent review, ‘Brighter Picture of Church Energy Use’, we analysed energy returns from churches since 2005, showing the effect of annual average temperatures on energy consumption. Temperatures in London rose from 2005 to 2007, then plunged from 2008 to 2010; after normalisation by degree days for each year, the ranking order for energy use (highest to lowest) was: 2005, 2006, 2009, 2007, 2008, 2010. This represents savings of 17% and at least 10.7%, in energy and carbon respectively. (Energy is the total taken from the grid for gas and electricity, plus oil, for all churches and associated halls in the Diocese; only gas and oil are normalised.) If we can maintain the same trajectory, we’ll be on course for 38% savings by 2020 and 76% savings by 2050 – that’s tough enough. And we need to accelerate a bit more to reach our target of 80% savings by 2050, so there’s a challenge ahead. Knocking down assumptions Some of our Climate Action Projects have already begun, such as boiler replacement and re-lighting – and solar panels. Solar panels on churches in the Diocese are all photovoltaic (PV). By generating electricity, these reduce electricity drawn from the grid, and therefore carbon emissions. Churches often have large south-facing roofs. It is widely assumed that solar panels should be hidden from view, especially on listed buildings or in conservation areas, but several schemes in the Diocese have demonstrated this need not be so. St Mary in Islington is the latest church in the Diocese to have had PV panels installed. St Mary’s is Grade II listed and in a conservation area. The mid-18th century tower by Launcelot Dowbiggin survived World War II, but the body of the church was destroyed in the Blitz and rebuilt with a flat roof during the 1950s. It leaked – so a new pitched slate and zinc roof was added in the 1990s. This new roof did not contribute to the character of the listed building enough to preclude any change. Nor was it deemed necessary to use solar imitation slates (as at St Silas in Pentonville [Building Conservation Journal March/April 2011]). The appearance of PV panels was accepted, as they occupy almost the entire slope, presenting a uniform appearance. Visible from the south-east, they can barely be seen from Upper Street, on which the church stands. Planning permission needed to carry out repairs, alterations and additions was granted without undue difficulty. The key principle under national planning policy guidance is to weigh the benefits of micro-generation for local sustainability, and their contribution to renewable energy nationwide, against any harm to the building’s character. There may be no harm, but even if there is that does not rule out approval – it depends whether the harm exceeds the benefits. The Borough of Islington has proved favourable to PV schemes, but all councils should assess applications in accordance with the national guidance (which is changing, but not so as to affect this principle). St Mary’s installation has an area of 156m 2 and a capacity of 22.015 kWp. In the three months from September 2011 when it was commissioned, it delivered more than 3,000 kWh of energy. Typically in London a PV array may generate up to 1,000 kWh per kWp per annum (highest in summer, lowest in winter). This depends on any shading or deviation from ideal pitch or orientation. St Mary’s system was estimated to deliver 18,683 kWh pa, 31% of the church’s energy demand. The project’s consultants also estimated the payback time for process and transport energy and carbon from the manufacture of the panels –
3.3 years and 4.1 years for energy and CO2 respectively. During the estimated 25-year lifespan of the system, the net CO2 that will be saved is estimated at 170 tonnes. The Feed-in Tariff PV panels benefit from the Feed-in Tariff (FiT), comprising a generation tariff (the rate depends on the capacity), plus 3.1p export tariff for each unit not used but fed back into the grid. This is usually deemed to be 50% of the total. If more than 50% is expected to be exported, an export meter can be installed separately to the generation meter. Peak use seldom aligns with generation and even when generation is less than consumption, a proportion will still be exported. 50% is a generous estimate, meaning a good deal for the generator. Current rates were to apply to systems installed and registered by 31st March 2012. However, the UK government’s latest review threw this into doubt, proposing a reference date of 12th December 2011. If implemented, schemes installed after that date would have moved to a lower tariff from 1st April 2012. (This was successfully challenged in Court, as it would have been retrospective. A deadline of 3rd March 2012 is now proposed and the changes as a whole remain to be confirmed.) Before the FiT was instituted in April 2010, PV owners were not rewarded for units generated, except under any deal from their utility company. On the other hand, a favourable grants regime contributed to capital cost – in particular the 50% grant from the Low Carbon Buildings Programme (phased out as the FiT was introduced). St Mary’s scheme was conceived in 2007. Progress was inhibited by subsequent changes to funding regimes (both capital and income). In the end, the scheme was fully funded by grants (see box, right). Increasingly, churches may need to borrow to bridge the funding gap. Income from the FiT will be needed to service and repay any loan and for any church using its own capital, say from a parish trust, payback under current FiT rates is about nine to 12 years. The proposed reduction in the generation tariff is about half, to 21p max; the additional export tariff is to be pegged at 3.1p. Continuing product development may help limit payback times to under 20 years. Installed costs have already dipped to about £2,500 plus VAT per kWp (it is customary to revise quotations downwards during procurement). Costs are expected to fall further even if the industry shrinks – though quality may suffer – and savings in purchased electricity from the grid also help, at an increasing rate as prices soar. However, the government is currently proposing to further reduce the generation tariff to 9p, for premises lacking an Energy Performance Certificate (EPC) Grade C, and/or not implementing measures under the Green Deal (to be introduced in late 2012). This would pose a problem for churches; EPCs are not designed for them (nor most public buildings). 70% of churches are listed buildings and most are pre-20th century – not well suited to the improvements (e.g. solid-wall insulation) recommended by EPCs and/or fundable under the Green Deal. Churches rely heavily on efficiency in use (not recognised by EPCs) and on renewable energy to drive down carbon footprints. We would like the government to recognise the Diocese’s Energy-saving Benchmarking system (see Building Conservation Journal March/April 2011, page 2) as the means of assessing measures already taken – thus justifying the full subsidy for micro-generation. Quick facts: PV installation at St Mary, Islington • Solar panels: 119 Sharp NU-185R1H panels; six Solarmax DC/AC inverters • Installation: Chelsfield Solar • Grants: Islington Climate Change Fund (ICCF), Big Lottery Community Sustainable Energy Fund, Richard Cloudesley’s Charity • Consultants to ICCF: Creative Environment Networks. Churches An example worth following We fully concur that a church spending capital on retrofitting should also take other measures including low-cost efficiencies and good management. St Mary’s Islington is a good example: • it is a member of the national Eco-congregation scheme, a tool to help churches address environmental issues in all they do • the church has undertaken an energy audit, and implemented measures including low-energy lighting and draught proofing • the church has also just replaced its boilers with new condensing boilers, also separating heating of the church from the crypt. The two spaces are used separately and at different times, thus heating them separately represents a major gain. Upgraded controls such as thermostatic radiator valves have further improved efficiency • funds have been raised for roof insulation (planned to follow shortly – it is easier to insulate a roof after installing solar panels than before, to avoid insulation being disturbed by the electrics). St Mary’s points the way to a holistic reduction of environmental impact in general, and energy use and carbon footprints in particular, that we would like to see imitated by churches everywhere. Further information Brighter Picture of Church Energy Use can be found at bit.ly/brighterpicture The Diocese of London’s Shrinking the Footprint microsite can be found at bit.ly/churchenergy Brian Cuthbertson is Head of Environmental Challenge at the Diocese of London brian.cuthbertson@london.anglican.org The previous two articles in the series by Brian Cuthbertson appeared in Building Conservation, March/April 2011, page 2, and Building Conservation, July/August 2011, page 2. www.rics.org/journals Related competencies include: M009, T012, T053 March-April 2012 Building Conservation Journal 3
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