Why Solar Panels Work in Southampton
Southampton is a good solar city with one quirk worth knowing. PVGIS, the European Commission’s model built on satellite records from 2005 to 2023, puts a 4 kW south-facing array at a 35° pitch in the city at 4,255 kWh a year. That is about 6% below the same array on the coast at Portsmouth or Havant (4,525 kWh) — a real difference, and one no installer quoting a national average will mention.
The city has adopted solar quickly. Government figures record 4,745 solar PV installations in Southampton at the end of 2024, up from 3,273 in 2020. The interesting number is the average size: 18.3 MW across 4,745 sites is about 3.9 kW each — the smallest average of any authority around the Solent, which is what a city of terraces, semis and converted flats looks like in the data.
What the output is worth depends on how much you use at home. At the 26.32p/kWh price cap for October to December 2026 and 12p/kWh on Outgoing Octopus for what you export, 4,255 kWh is worth about £693 a year at 30% self-use and about £876 at 60%.
To use more of what you generate, pair the panels with battery storage in Southampton, or add an EV charger. If you are weighing up whether it is worth it here, our breakdown of Southampton’s solar figures goes through the data behind this page.
Planning in Southampton
Southampton City Council is the planning authority. Roof-mounted panels on a house are permitted development if they project no more than 0.2 m from the slope and sit no higher than the highest part of the roof. The city has 20 conservation areas — among them Carlton Crescent, The Avenue, Old Town North, South and West, Portswood Residents’ Gardens and the Old Woolston areas — and inside them only panels on a wall, balcony or roof enclosure fronting a highway are excluded. Two things change the answer: a listed building, and an Article 4 direction (Southampton has used them on specific streets). A flat above a shop or in a converted house usually needs the freeholder’s consent as well as planning.
What a 4 kW System Is Worth in Southampton
4 kW south-facing at 35° (PVGIS, EU Joint Research Centre). Values use the 26.32p/kWh price cap for Oct–Dec 2026 and 12p/kWh Outgoing Octopus export. Cost: DESNZ 2025/26 South East average of £1,859/kW for systems up to 4 kW. Your quote follows a survey.
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Solar Panel Costs & Savings in Southampton
Put those together for Southampton and an average 4 kW array — 4,255 kWh a year on a south-facing roof — costs about £7,436 and is worth £693 a year if you use 30% of its output at home, or £876 if a battery or daytime occupancy lifts that to 60%. That is a simple payback of roughly 8 to 11 years before any battery, and it moves with the price cap.
Those are averages across tens of thousands of installations, not a quote. Scaffold access, roof type, the number of panel strings and whether you add a battery all move the price, which is why every quote follows a survey. Solar panels and batteries installed in homes are zero-rated for VAT until 31 March 2027, and Smart Export Guarantee payments are only available on an MCS-certified installation.
Our Hampshire solar panel cost guide goes through system sizes and options in more detail.
Terraces, Flats and Shared Roofs in Southampton
The average Southampton installation is 3.9 kW — roughly ten panels. That is the city’s housing showing through: Victorian and Edwardian terraces in Portswood, St Denys and Shirley, post-war semis in Bitterne and Harefield, and a large stock of converted flats. On a terrace the usable roof is one slope, often facing east or west, and the array is shaped by chimney stacks, dormers and a neighbour’s extension rather than by your budget.
An east-west split is normal here and still worth doing: on the nearby coast PVGIS models an east-facing 4 kW array at about 77% of a south-facing one over a year, with most of the shortfall in winter. What matters more is shading — a single mature street tree or a taller neighbouring roof can cost you more than the orientation does, which is why the survey looks at the roof at the time of day you actually use electricity.
If you own a flat, the roof almost certainly is not yours. A leaseholder needs the freeholder’s written consent, and in a converted house with a shared roof every leaseholder normally has to agree; the same is true of a managed block. It is worth settling that before anyone quotes, because it decides whether the job is possible at all.
Conservation areas cover a good deal of the older city. The national rules still allow roof-slope panels there, but an Article 4 direction can withdraw permitted development rights street by street, and Southampton has used them. Check your address on the council’s conservation-area pages first; our guide to solar panels in conservation areas sets out what the national rules do and do not restrict.
Services Available in Southampton
Solar Panel Installation
Premium solar panels installed on homes across Southampton. 3kW–6kW+ systems, 0% VAT, 25-year warranties. MCS certified.
Battery Storage
Store solar energy and charge overnight on cheap rates. GoodWe, Fox ESS, SigEnergy from £3,600. 0% VAT applied.
EV Charger Installation
Charge your EV from free solar. Zappi smart chargers, Ohme scheduling, SigEnergy 25kW DC. OZEV approved from £700.
Battery Storage & EV Charging in Southampton
Maximise your solar investment with battery storage and charge your EV from free solar.
Battery Storage Southampton
Store free solar energy and charge it overnight on an off-peak tariff.
EV Chargers Southampton
Charge your EV from free solar or on a cheap overnight tariff. Zappi, Ohme & SigEnergy 25kW DC. OZEV approved.
How a Southampton Installation Runs
Survey
We check roof pitch and direction, the state of the covering, shading from trees and neighbouring roofs, the route to your consumer unit and, on a flat or a terrace, who actually owns the roof.
Design and fixed quote
You get a written design and a fixed price, with any conservation-area, Article 4 or freeholder-consent step flagged before you commit.
Network paperwork
SSEN is the distribution network operator here. Systems up to 16 amps per phase (3.68 kW on a single-phase supply) are notified under G98 after commissioning; anything larger — including many battery add-ons — needs a G99 application approved before installation.
Installation and testing
Scaffolding goes up first. The array, inverter and any battery are then fitted, the circuits are tested, and the system is commissioned before the scaffold comes down.
Handover
You receive the MCS certificate — needed to claim Smart Export Guarantee payments — with the commissioning records and warranty documents.
Solar Panel FAQs for Southampton
Answers use sourced figures: PVGIS for output, DESNZ for costs and installation counts, Ofgem and Octopus for rates.
Government data for the South East put the 2025/26 average at £1,859 per kW of panels for systems up to 4 kW — about £7,436 for a 4 kW array — and £1,721 per kW for 4–10 kW systems. Scaffolding on a terraced street, roof condition and any battery move the price, so we quote after a free survey. Installation in a home is zero-rated for VAT until 31 March 2027.
PVGIS models a 4 kW south-facing array at a 35° pitch in Southampton at 4,255 kWh a year, about 6% below the same array on the coast at Portsmouth or Havant. An east- or west-facing roof gives up roughly a fifth over the year, most of it in winter.
At October–December 2026 rates — 26.32p for electricity you use and 12p for what you export — a 4 kW array producing 4,255 kWh is worth about £693 a year if you use 30% at home and about £876 at 60%. Against the South East average cost of about £7,436, that is a simple payback of roughly 8 to 11 years before any battery.
The Department for Energy Security and Net Zero recorded 4,745 solar PV installations in Southampton at the end of 2024, up from 3,273 in 2020. The average size is about 3.9 kW — the smallest of the authorities around the Solent, and a fair reflection of a city of terraces and flats.
Only with the freeholder’s written consent, and in a converted house or managed block usually with the other leaseholders’ agreement too. The roof is rarely demised to the flat. Settle consent before you take quotes — it decides whether the job can happen.
Usually not. Roof-mounted panels on a house are permitted development within the 0.2 m projection and roof-height limits, including in Southampton’s 20 conservation areas, where only panels on a wall, balcony or roof enclosure fronting a highway are excluded. Listed buildings need consent, a flat-roof array in a conservation area needs prior approval, and an Article 4 direction can remove the rights on particular streets.
SSEN. We confirmed it by postcode rather than by county: SO14 returns grid supply point group _H (Southern). Systems up to 16 A per phase (3.68 kW single phase) are notified under G98 after commissioning; anything larger needs a G99 application approved before installation.
Brands We Install in Southampton
Three industry-leading brands to suit every budget and requirement
SigEnergy
Premium 5-in-1 system with integrated EV charger
Fox ESS
Hybrid inverters and stackable home batteries
GoodWe
Hybrid inverters and batteries, including three-phase options
Not sure which brand? Compare them:
Solar, Battery & EV Services Near Southampton
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Related services & guides
Solar Panels near Southampton
Southampton's Victorian terraces (Portswood, Shirley, St Denys) and inter-war semis (Bitterne, Sholing) each need different mounting and DNO approaches — all handled in-house with SSEN G98/G99. Your grid operator is SSEN, your planning authority is Southampton City Council — we handle the G98/G99 paperwork on every install.
We also install solar panels in these nearby areas:
Running a business here? We handle the commercial side separately — structural checks, three-phase supplies, SSEN G99 applications and year-one tax relief. See commercial solar installers in Southampton.
Looking beyond Southampton? Costs, panel brands, roof types and the SSEN paperwork vary across the county. Our county guide covers what solar actually costs in Hampshire in 2026 and which brands hold up on south-coast roofs. See solar panels in Hampshire.