8.2.1 Solar photovoltaics (PV)

8.2.1.3 System design

Solar PV technologies shall be designed to ensure satisfactory performance. Issues to be taken into account include:

  1. location
  2. system
  3. compatibility
  4. performance
  5. diverters
  6. battery and storage.

8.2.1.3.1 Location

Solar PV systems should be correctly located, including ancillary components, and should be installed and identified in accordance with the manufacturer’s recommendations.

The design and location of solar PV technologies should take account of factors such as:

  • orientation
  • roof pitch
  • coastal location
  • snow loading
  • shading.

When installed in a coastal location, fixings and bracketry should be appropriate for the area, and stainless steel grade 316 should be used where appropriate.

8.2.1.3.2 System

Solar PV technologies should be designed in accordance with the manufacturer’s recommendations, certification scheme requirements and appropriate standards.

Each system should generally be supplied from one manufacturer as a package, not as individual components or materials. However, where components from more than one manufacturer are used, they should be compatible to ensure satisfactory performance.

Mixing of electrical MC4 type connections (male and female) is not acceptable unless specifically allowed by the manufacturer.

8.2.1.3.3 Compatibility

Solar PV technologies should be installed so as not to adversely affect the performance of the building to which they are fixed, and in accordance with the manufacturer’s recommendations.

Multiple systems should be compatible with each other.

The temperature rating of any roof underlay should be suitable for use with a solar PV system and accessories used.

When using roof integrated solar panels, ventilation must be maintained in accordance with BS 5250. Also see Clause 7.2.15.

8.2.1.3.4 Performance

Solar PV systems designed to contribute towards space and water heating should be designed in accordance with the performance requirements in Clauses 8.1.8 and 8.3.2.

8.2.1.3.5 Diverters

The provision of immersion diverters is discretionary. Where used, they should be designed by a competent person to prevent any adverse operation to the installed electrical installation either upstream or downstream, including RCD and islanding protection.

8.2.1.3.6 Batteries and storage

Also see:

8.1.6

The provision of battery storage is discretionary. Where used, they should be designed by a competent person and in conjunction with the IET Code of Practice for Electrical Energy Storage Systems and BS 7671 18th Edition wiring regulations and:

  • the installation should be in line with MIS 3012 and manufacturer’s installation instructions
  • the inverters must be fully type tested to the standards required by the Energy Networks Association recommendations
  • the batteries and storage equipment should not be located where they are at risk of accidental damage or where their enclosures are not designed for
  • batteries intended for use in dwellings should be housed in a suitable enclosure meeting the relevant IPX rating
  • batteries/storage should not be placed so that escape routes are impeded, and that any fire in the battery does not compromise protected escape routes
  • where batteries are located they should have sufficient ventilation to prevent overheating and prevent explosive conditions of evolved gasses
  • should not be designed and installed where foreseeable flood or water inundation conditions may occur.

Further guidance relating to battery installation can be found in PAS 63100 Electrical installations — Protection against fire of battery energy storage systems for use in dwellings.

Last updated: 2nd January 2025

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