Solar installation – The essentials.

Hardware Kit for Solar Panel Installation in the UK (Updated)

Essential Components:

• Solar Panels The core component that converts sunlight into electricity. These come in various wattages and sizes to suit your energy needs and roof space.
• Mounting System This secures the solar panels to your roof. Mounting systems vary depending on your roof type (tiled, slate, metal etc.) and pitch.
• Roof Hooks These metal hooks firmly attach the mounting rails to the roof rafters.
• Rails These extruded aluminum rails are fixed to the roof hooks and hold the solar panels in place.
• Electrical Connectors These weatherproof connectors allow you to connect the solar panels together in series or parallel to create the desired voltage and current output.
• MC4 Cable This UV and fire-resistant cable carries the DC current from the solar panels to the inverter. Ensure you use the correct size cable for your system’s amperage.
• Inverter The inverter converts the DC electricity generated by the solar panels into AC electricity for use in your home or feeding back to the grid
• Inverter Enclosure (Optional): Provides weather protection for the inverter, especially if it’s installed outdoors.
• AC isolator Switch: A safety device that allows you to disconnect the AC output from the inverter for maintenance or emergencies.
• DC Isolator Switch (Mandatory in UK): This safety switch disconnects the DC current from the solar panels to the inverter, crucial for maintenance and emergencies. UK regulations require a DC isolator.
• Metering Equipment (May be required by your grid connection provider): This equipment monitors the electricity generated by your solar system and may be required by your energy provider for grid connection purposes.
• Monitoring System (Optional): Allows you to track your system’s performance and identify any potential issues.

Mandatory Stickers:

• Solar PV Installation Sticker: This sticker clearly identifies the presence of a solar PV system on the premises. Its exact format may vary depending on the manufacturer, but it should comply with BS EN 60414-1:2014 standards.
• DC/AC Isolator Switch Label: A label indicating the location and function of the DC/AC isolator switch. This is crucial for safety personnel during maintenance or emergencies.

Additional Hardware:

• Cable ties: For securing cables neatly.
• Cable glands: Maintain weatherproof seals where cables enter enclosures.
• Warning labels: Mark additional potential hazards, following best practices.
• Earthing equipment: Grounding the system for safety (not always required).
• Fixings: Screws, nuts, bolts etc. to secure various components.
• Stickers: “Do Not Operate” on the isolator switch and “Solar Panels – Do Not Touch” on the array frame can enhance safety and clarity.

Planning Notes:

• This list is a general guide, and the specific hardware required will depend on your system size, roof type, and grid connection setup.
• Always consult with a solar installer to ensure you have the right equipment for your specific project and to comply with all relevant UK regulations, including sticker requirements.
• Some electrical components may require a qualified electrician for installation.
  
  

Electrical Work on Solar Panel Installations in the UK: Homeowner vs. Electrician (Competent Person).

In the UK, electrical work in a dwelling is governed by Part P of the Building Regulations 2010 [1]. This section outlines what homeowners can do themselves and what requires a qualified electrician (competent person) when it comes to solar panel installations.

Homeowner (DIY) Work:

• Replacing Like-for-Like: You can replace existing light fittings, switches, or sockets with functionally identical models, provided the wiring is already in good condition and hasn’t been modified (Regulation 7(2)(a) of Part P [1]).
• Adding Plugs: Adding a new plug to an existing, undamaged extension cord might be permissible. However, exercising caution is crucial to ensure the overall circuit isn’t overloaded (Regulation 7(2)(a) of Part P [1]).

Important Note: Any work involving mains voltage (230V) or modifying existing circuits is not permissible for homeowners in the UK. That includes:

• New Circuits: Installing a new circuit to connect your solar panel inverter to your home’s electrical system requires a qualified electrician (Regulation 12(2)(a) of Part P [1]). This ensures the circuit meets safety standards (BS 7671: Requirements for Electrical Installations [2]) and doesn’t overload existing wiring.
• Repurposing Existing Circuits: Modifying an existing circuit to accommodate the solar panel system requires a qualified electrician (Regulation 12(2)(a) of Part P [1]). Altering circuits can lead to safety hazards if not done correctly (BS 7671 [2]).

Electrician (Competent Person) Work:

For a solar panel installation, a qualified electrician registered with a government-approved Competent Person Scheme is required for several key aspects:

• Inverter Connection: Connecting the inverter to your home’s electrical system requires a certified electrician (Regulation 12(2)(a) of Part P [1]). They will ensure the connection is safe, adheres to regulations (BS 7671 [2]), and doesn’t overload existing circuits.
• DC Isolator Switch: While some homeowners might be tempted to install the DC isolator switch themselves, regulations in the UK mandate this to be done by a competent person (Regulation 12(2)(a) of Part P [1]). The electrician will ensure proper placement and functionality of this crucial safety device (BS 7671 [2]).
• Earthing: Proper earthing of the solar panel system is essential for safety. A qualified electrician has the expertise and knowledge to ensure the system is grounded according to regulations (BS 7671 [2]).

Building Control Inspection and Testing:

• Building Regulations Notification: Depending on the size and complexity of your solar panel system, you may need to notify your local building control authority before installation (Building Regulations 2010 [1]). Here’s a breakdown of when notification is typically required:
  • Generally Required: Systems exceeding 50kW DC output (Schedule 1(1)(a) of the Building Regulations 2010 [1]).
  • May Be Required: In some cases, even smaller systems might require notification, so it’s always best to check with your local building control authority or a qualified electrician.
• Inspection and Testing: Following notification and installation, your local building control authority may conduct inspections and require testing to ensure the system complies with relevant safety regulations (Building Regulations 2010 [1]). This may involve verification of:
  • Electrical safety (BS 7671 [2])
  • Fire safety
  • Structural integrity
    
    See Regulation 44. 44ZA ( check act for amendments link [1] below)
    
    • 44ZA.—(1) This regulation applies to building work in respect of a building in relation to which paragraph L2 of Schedule 1 imposes a requirement, but does not apply to the provision or extension of any system for on-site electricity generation where testing and adjustment is not possible.
    • (2) Where this regulation applies the person carrying out the work must, for the purpose of ensuring compliance with paragraph L2 of Schedule 1, give to the local authority a notice confirming that the system for on-site electricity generation has been commissioned.
    • (3) The notice must be given to the local authority—
    • (a)not later than the date on which the notice required by regulation 16(4) is required to be given; or
    • (b)where that regulation does not apply, not more than 30 days after completion of the work.”.

Additional Requirements:

• Building Regulations Notification: Depending on the size and complexity of your solar panel system, you may need to notify your local building control authority before installation (Building Regulations 2010 [1]). A qualified electrician can advise you on this requirement.
• Competent Person Scheme: It’s highly recommended to use an electrician registered with a government-approved Competent Person Scheme (e.g. NICEIC, ECA [3]). This ensures they are qualified and up-to-date on the latest regulations for solar panel installations (BS 7671 [2]).

Following these guidelines and using a qualified electrician for essential tasks ensures your solar panel installation is safe, meets regulations, and functions optimally.

References:

[1] https://www.legislation.gov.uk/uksi/2010/2214/contents/made [2] https://www.theiet.org/ (BS 7671: Requirements for Electrical Installations) [3] https://www.competentperson.co.uk/

While BS 7671 doesn’t offer step-by-step instructions for solar, it provides crucial details for safely connecting solar panels or generators to your existing electrical system:

• Section 712: This section specifically addresses photovoltaic (PV) installations, which is the technical term for solar panels that convert sunlight into electricity. However, the general principles can apply to generators as well. It highlights the importance of following the manufacturer’s instructions for the specific microgeneration system you’re using.
  
• Regulation 551.7: This regulation outlines essential safety requirements for connecting microgenerators (like solar panels) to a final circuit. Here are some key points:
  • A protective device (like a fuse) might need to be replaced with one with a lower current rating to accommodate the additional power from the microgenerator.
  • The microgenerator cannot be connected to the final circuit using a plug and socket.
  • An RCD (residual current device) might be required to provide additional protection for the final circuit.
  • The line and neutral conductors of the final circuit or the microgenerator must not be connected to Earth (grounded).

Following Manufacturer Instructions:

BS 7671 emphasizes the importance of following the manufacturer’s instructions for your specific solar panel or generator system. These instructions will provide detailed information on installation, connection, and safety requirements specific to your equipment.

MORE:
Link to BS7671 ARTICLE

IET (solar) ARTICLE

link to PART P building regulations and check list.