Community Photovoltaics

Overview

With the availability of £50m worth of governments grants for renewable energy systems on public and community buildings over the next year, now is the time to install solar PV. This funding will cover 50% of the cost of a PV system, has none of the onerous energy efficiency demands of the previous grant scheme, and is only expected to be around for another year (with no planned successor scheme).

We are currently helping five churches in the UK through the funding process (from various sources), and have developed a bespoke 'lead roll clamp' for one of these which should open up the possibilities for many other churches with lead roll roofs. Solstice Energy can call on its own rope access specialist which can save the damage and expense of scaffolding structures on large buildings. We consider ourselves the church PV specialists!


Case study - St Aldhelm's Church halls

A previous success story for Solstice Energy is the 18.4kWp system on the roof of St Aldhelm's church community halls in Edmonton, North London. The system was switched on by the Mayor of Enfield on May 13th 2006, and has been widely used as a prime example of what is possible when there is a will.

Among the exposure has been a BBC report made during installation, and filming took place there for the channel 4 programme "God is Green".

Mr Chris Littler, St Aldhelm's hall manager, collected the award and a cheque for £500 from the Bishop of Ealing for "Energy Saving in Church Buildings" at The Church Times Green Awards on November 19th 2007 at St Mary le Bow.


The Process

The mounting system is a semi-integrated method which requires the removal of the roof tiles where the array is sited. There will be no future problems of loose or damaged tiles underneath the array.

The 'intersol' plates are made of heavy duty recycled plastic and perform the water-proofing duties in place of the tiles. If the halls need re-roofing in say 5 years time, this can be done around the array without needing to disturb the PV modules.

The end result is a neat system which is only proud of the surrounding tiles by about 20mm. At St Aldhelm's they believe the PV array adds to the visual appeal of the halls rather than detracts from it.

Three inverters control the PV system and send information to a data-logger which can then be retrieved on a p.c. A public display meter has also been installed, and is a valuable educational tool.


Crunching the numbers

St Aldhelm's are blessed with 3 big South-facing roofs, and at 18.4kWp it is a large system. Most community PV projects tend to range between 5 and 12kWp.

The system cost £92,400 (inc 5% VAT) for supply, installation and commissioning. Comprising funds from:

  • DTI (now DBERR) £46,200
  • EDF Green Fund £30,000
  • Enfield Council £2500
  • St Aldhelm's £13,700

In the 10 months after having an export meter fitted, from Jan - Nov 2007 (not a very sunny summer!) there was:

Total generation of 16152kWh

Of which, 13209kWh was exported and 2943kWh was used on site.

St Aldhelm's have signed up with electricity suppliers Good Energy Ltd who source all of their power from renewable energy.

The financial value of the PV system is:

The ROC's (Renewable Obligation Certificates) are worth 4p for every kWh generated, so 16152 x £0.04 = £646
Good Energy's export value is 3p, so 13209 x £0.03 = £396
Savings on electric bills at 10p / kWh, 2943kWh x £0.10 = £294

The sum of this financial benefit is £1336. As it's only 10 months figures lets round it up to £1400 for year 1.

If you refer to the interest calculator, you'll see that with a combination of inflation and electricity price rises of just 7% their costs of £13,700 will be returned within 8 years and doubled within 13.

St Aldhelm's were fortunate with the £30,000 EDF funding on top of the DTI funding, but even if you take away the EDF money, their costs of £43,700 would be returned in 17 years and doubled in 25. Even if you disregard the possibility of future legislation making renewable energy more valuable, this PV system will not only pay for itself - it will make lots of money!*

Have a play with the spreadsheet and you'll see the effect of different interest rates. A better value on exported power such as is offered by Powergen would improve the year 1 figure even more (by over £500), but St Aldhelm's are sticking with Good Energy for ethical reasons.

The modules, which are the most expensive part of the system by far, are normally guaranteed for 20/25 years to 80% of their power (10 years to 90%). The expected lifetime of the system is around 50 years or more.

* This isn't how we like to sell PV installations - it should be an environmental investment before a financial one, but there is so much negative information out there on the subject of 'payback' that we wanted to show the reality.

St Aldhelm's are blazing a trail for their community. Many people of different faiths and ages use the Church and the halls, and the PV system is a very visible statement of intent and leadership from the church in Edmonton. St Aldhelm's were active in community environmental schemes before May 2006, but since then the PV has been the springboard for even greater efforts. Not everyone can afford or is able to install renewable energy on their own home, but people go away from St Aldhelm's inspired and feeling that they are not alone in making their own efforts to improve their environment.