Solar Panel Installation

A solar PV (photovoltaic) system has four main parts:

• Panels: Mounted on the roof, they generate direct current (DC) electricity from daylight. System size is given in kWp (kilowatts peak), the output under test conditions.
• Inverter: Converts DC into the alternating current (AC) your home uses. Usually one unit in the loft or garage; microinverters or optimisers on each panel help where part of the roof is shaded.
• Generation meter and monitoring: Records what the system produces, usually with an app.
• Connection: The inverter connects to your consumer unit on its own protected circuit, with isolators.

Your home uses the solar electricity first. Anything you do not use is exported to the grid, unless you have a battery.

• Orientation: South-facing roofs generate the most; east and west-facing roofs also work well. North-facing roofs are usually not worth it.
• Shading: Chimneys, trees and neighbouring buildings reduce output.
• Condition: Loose tiles, failing felt or a worn flat roof should be repaired before installation, not after.
• Structure: The roof must carry the extra weight and wind loads, so we check the rafters at the survey.
• Roof type: Pitched roofs use brackets fixed to the rafters; flat roofs use angled frames.

If you are planning a loft conversion or a house extension, it often makes sense to fit solar while the scaffolding is up and the roof is new.

A battery is optional. It stores daytime solar electricity for use in the evening, instead of exporting it. Whether it makes sense depends on how much electricity you use when the sun is not shining. Batteries can be fitted with new panels, using a hybrid inverter, or added later, and are positioned to the manufacturer's guidance, typically in a garage, utility room or loft.

For most houses in England, no. Roof-mounted solar panels are usually permitted development, within limits:

• Projection and height: Panels must not stick out too far from the roof slope or rise above the highest part of the roof (excluding the chimney).
• Appearance: They should be sited, as far as practicable, to minimise the effect on the building's look.
• Conservation areas: Extra limits apply, particularly to panels on walls facing the street.
• Listed buildings: Listed building consent is normally needed.
• Flats: Do not have the same permitted development rights, so planning permission and the freeholder's consent are usually needed.

The new circuit for the inverter is notifiable electrical work, and is certified through one of the routes the building regulations allow. Where the roof structure needs strengthening, building regulations approval may also apply.

Every grid-connected system must be registered with the distribution network operator (DNO); in London, UK Power Networks.

• G98: Smaller systems, up to around 3.68 kW per phase of inverter output, can be connected first and the DNO notified within 28 days of commissioning.
• G99: Larger systems need an application and DNO approval before they are connected. The DNO may limit how much can be exported.

We handle the DNO notification or application as part of the installation.

The SEG requires larger electricity suppliers to offer a tariff that pays you for the electricity you export. Each supplier sets its own rate, and you need a meter that records exports, usually a smart meter.

To receive Smart Export Guarantee payments, the installation generally needs MCS certification (the Microgeneration Certification Scheme), covering both the installer and the products. Before you order, confirm with us whether your installation will come with an MCS certificate, and check your chosen supplier's requirements.

For many homes, yes, but it depends on your circumstances. The main factors are:

• Your roof: Orientation, shading and usable space.
• When you use electricity: Homes occupied during the day use more of their own solar power.
• A battery, EV or heat pump, which can use more of what you generate.
• Electricity prices and export rates at the time.

We do not quote savings or payback figures, because they depend on all these factors. At the survey we explain how a system would suit your roof and electricity use.

• Scaffolding: Roof work needs safe access, so scaffolding is normally erected. A council licence is needed if it stands on the pavement.
• Bird protection: Pigeons often nest under panels, causing mess and damaging cables. Mesh guards around the array prevent this and are easiest to fit at installation.
• Maintenance: Panels need little. Check the monitoring app so you notice a drop in output; the inverter and connections can be inspected during periodic electrical maintenance.