Energy Saving Trust
North East Renewable Energy Directory
Grass - technologies
Factors to consider

Questions to ask suppliers

  • Is your product certified under the Microgeneration Certification Scheme (MCS)? The MCS underpins the Low Carbon Buildings Programme, which provides grants for installing renewable energy technologies. MCS is designed to evaluate products and installers against robust criteria for microgeneration technologies. Visit this website to find an MCS approved product. Does your product meet the requirements of the relevant BSI British Standard? Relevant BSI British Standards include (depending on the type of PV module): BS EN 61215:2005 Crystalline silicon terrestrial photovoltaic (PV) modules. Design qualification and type approval; BS EN 61646:1997, IEC 61646:1996 Thin-film terrestrial photovoltaic (PV) modules. Design qualification and type approval.
  • What is the installed peak power of your PV system?  Most domestic systems usually between 1 and 3 kWp. A 1kWp system is enough to run appliances and processes that are in constant use for a typical UK dwelling.
  • Is your PV system grid-connected or stand-alone? Grid connected systems require very little maintenance and allow you to export excess electricity to the grid.  Stand-alone systems, i.e. those not connected to the grid, need maintenance on other system components, such as batteries and are usually are used in situations where grid power supplies are unavailable or difficult to connect to.
  • What type of PV cells are used in your system? The following types of PV cells are listed in order from most to least efficient (and expensive): monocrystalline silicon cells, multicrystalline silicon cells, thin cell technologies (e.g.  cadmium telluride (CdTe) and copper indium diselenide (CIS)) and amorphous silicon. Most PV cells used for land-based applications are based on one of the silicon technologies.

Questions to ask installers

  • Are you certified under the Microgeneration Certification Scheme (MCS)?  MCS is designed to evaluate products and installers against robust criteria for microgeneration technologies. Visit  www.microgenerationcertification.org to find an MCS approved installer:
In order for a PV installation to be cost effective the following factors should be considered:
  • A suitable area of at least 10m2 is available
  • The area to be covered should not be shaded by other buildings or trees
  • The most effective roofs face between south-east and south-west.
  • Installation of solar PV panels is a permissable development and does not normalt require planning approval. If they project beyond the roofline or are  in a conservation area or on a listed building it is prudent to contact your local planning authority to ascertain if they require planning permission.
  • What type of photovoltaic system would be suitable?

When designing roof mounted systems checks should be made to ensure that the roof structure is able to support the additional weight of the panels, and that the fixings are able to withstand wind uplift on the panels. BRE Digest 489 provides guidance on calculating wind loads and is available  at http://www.brebookshop.com/details.jsp?id=146655.
 
Some housing providers have reported vandalism (damage from objects being thrown at the panels), so consideration should be given to appropriate protection if panels are in a vulnerable location

Photovoltaic modules can be placed on almost any building surface that receives sunshine for most of the day. Roofs are the usual location for PV systems on houses but photovoltaic modules can also be placed on facades, conservatory or atrium roofs, sun shades, etc.

If a PV installation is being considered as part of a new build programme, or during scheduled roof repair, then the use of a system designed into the building (Building Integrated) such as roof tiles could be considered. These systems effectivly replace the building material i.e. tiles, glass or cladding on a like for like basis but have the added benefit of producing electricity. Building integrated systems generally have a shorter payback period, as the cost of system is effectively only the difference between conventional building products and solar ones.

However, if the roof is not being re-done then modules mounted on the existing surface (a bolt-on system) are probably the most cost effective option. These systems sit on top of the existing building materials on a bracket or mounting system. Most systems do not sit flush with the roof line. These systems are generally cheaper to purchase and can be installed relatively simply with little inconvenience to the building occupier. 

Generally the balance of system components (the wires and the inverter) will be housed in the loft space of the building. To minimise losses through the system the systems are often designed to house the inverter as close to the PV system as possible so that the power can be converted to AC near to the point of generation. Wiring will then taken to the main distribution box and the power will be synchronised with electricity demand from the grid.
 

Regulation check

Building Regulations:

If you are installing a PV panel on your roof the Building Regulations will apply. The ability of the existing roof to carry the load (weight) of the panel will need to be checked and proven. Some strengthening work may be needed. Building Regulations also apply to other aspects of the work such as electrical installation and plumbing work.

Source: www.planningportal.gov.uk/england/genpub/en/1115315125873.html

Planning permission:

Planning permission is now only required if the PV panel will project more than 200mm from your roof’s surface or if it is will face onto or be visible from the highway in homes in conservation areas and World Heritage Sites. Planning permission is still required for listed buildings. If your home is a listed building or in a conservation area, you should contact your local planning authority.

Source: www.opsi.gov.uk/si/si2008/uksi_20080675_en_1
 
Heritage Issues:

If you are intending to carry out works to improve energy efficiency to a listed building or a building in a conservation area first check with the local planning authority whether any consent may be required. Alterations that affect the external or internal appearance (in the case of listed buildings) and character including any materials, details and finishes may well require consent. Local planning authority conservation officers can also advise on the balance between historic building conservation and energy efficiency in historic buildings. Large numbers of traditional buildings are not listed or situated in any designated areas. Many of these will nevertheless have features of some historic interest. This means that any adaptations made to improve energy efficiency need to take account of the traditional performance of the building fabric and its compatibility with the new materials that are being proposed

Find your local planning authority at:
http://www.planningportal.gov.uk/wps/portal/genpub_LocalInformation?docRef=1103046453478&scope=202&langid=0.
Source: www.planningportal.gov.uk/england/genpub/en/1115315126253.html
For more information visit the English Heritage web-site linked to improving the energy performance of listed buildings.  www.climatechangeandyourhome.org.uk

If you have a home of traditional construction, English Heritage’s publication Small scale solar electric (photovoltaics) energy and traditional buildings provides a useful guide. Available at: http://www.helm.org.uk/upload/pdf/49357-SolarElectric.pdf

Installation considerations

Installation is a relatively straightforward job for an MCS accredited installer. Use of an accredited company will reduce the risk of complications arising, perhaps due to a roofer not being confident to connect wires or an electrician not being confident on a roof. The only part of installation that requires a fully qualified electrician is the connection into the household fuse box. However, care needs to be taken connecting panels together when the sun is shining as large voltages can be generated. Codes of practice should be followed.
If you choose not to use an MCS accredtited company your installation will not be paid the Feed-in-Tariffs.

Maintenance considerations

PV installations have no moving parts and require minimal maintenance. However they need to remain clean for optimum performance and regular cleaning to remove dust accumulation may be needed. However, systems can be designed and located so that they can ‘self-clean’ when it is raining.

Lifetime

The durability of PV cells varies according to the type of cell used. For silicon based PV cells the lifespan should be at least 25 years, depending on the type of cell used. The inverters and control software used to step-up the PV direct current to 230V AC may need replacing once in a typical panel's lifespan.

If you would like to be included in this directory please contact us here:
North East Renewables, 18B Manor Way, Belasis Hall Technology Park, Billingham, TS23 4HN Tel: 01642 373028 Email: advice@n-e-renewables.co.uk"