We have from the outset been keen to install solar PV, where financially prudent to do so. Cathedral House has various flat roofs with potential for small arrays. The higher north west roof required substantial refurbishment in 2018 and this presented an opportunity to simultaneously install a 6.6kW (24 x 275W panels) solar array.

Working in partnership with Portsmouth City Council's energy team and Portsmouth based installer Space Renewables we commissioned the array in September 2018. The panels sit below the parapet wall thus having some protection from high winds and being invisible from the street.

The array primarily serves our first floor administrative offices, thus much of the printing of service leaflets, letters etc is now solar powered. It also serves the scholars flats above the offices, which provide additional weekend demand when the offices are closed.

Since commissioning the array has generated c36,000kWh of electricity and we estimate that in excess of 80% of this has been consumed on site. Our grid electricity tariff has risen 200% since the array was installed, thus the solar generation has helped cushion against a substantial price hike. The array also earns inflation-adjusted feed-in tariff (FIT) income under the UK microgeneration framework. This income combined with grid electricity bill savings is likely to result in project capital cost payback of less than 10yrs.

When the smaller north east roof comes up for refurbishment there would be potential to add a further 2.2kW array. There is also potential for an array on the Cathedral high nave pitched roof, which is not visible from the street. However, this would require additional expenditure on associated strengthening works given the greater exposure to high winds.

Gallery - Installation September 2018