Solar Panel Installer Southport · an independent guide · Money
Batteries with solar in Southport: when one adds up
A battery stores the midday surplus for the evening. Whether you have a surplus worth storing depends on your roof and on when you use power. Here is Southport's month-by-month picture for two typical roofs.
Figures checked at source on 3 November 2026. Written by SEO Dons, who neither sell nor fit solar panels.
The surplus, month by month
The table shows average daily output for two of the planner's example roofs: the large south-facing villa slope and the smaller south-west front of a hipped inter-war semi. Set against them is a typical home's use of 2,500 kWh a year, which is about 6.8 kWh a day if spread evenly. Real use is higher in winter and in the evening.
| Month | Villa, 5.72 kW south | Semi, 3.08 kW south-west | Typical use |
|---|---|---|---|
| Jan | 6.2 | 2.7 | 6.8 |
| Feb | 11.5 | 5.2 | 6.8 |
| Mar | 16.7 | 8.0 | 6.8 |
| Apr | 22.6 | 11.5 | 6.8 |
| May | 23.9 | 12.8 | 6.8 |
| Jun | 23.3 | 12.6 | 6.8 |
| Jul | 22.4 | 12.2 | 6.8 |
| Aug | 20.7 | 11.0 | 6.8 |
| Sep | 17.4 | 8.7 | 6.8 |
| Oct | 11.5 | 5.4 | 6.8 |
| Nov | 7.7 | 3.4 | 6.8 |
| Dec | 5.6 | 2.4 | 6.8 |
kWh a day. Output from PVGIS 5.3 monthly figures for central Southport at 40 degrees, 14% losses; use from Ofgem's typical consumption value. Read on 3 November 2026.
Two things stand out. From spring to early autumn the larger roof makes two or three times what the house uses on an average day, so without a battery much of it is exported. In the darkest months both roofs make less than the house uses, so a battery has little to store and the panels' output is used as it comes. That is why a battery's value is mostly a summer-half-of-the-year value.
What a stored unit is worth
A unit of solar power used in the house saves the import price: 26.32p per kWh on average under Ofgem's cap for October to December 2026. The same unit exported earns your export rate, which ranges from a few pence to around 13p on the better tariffs. A battery's value is that gap, applied to the extra units it lets you use rather than export, less what is lost in charging and discharging. A battery that shifts 5 kWh a day for six months of the year moves roughly 900 kWh; at a 15p gap that is about £135 a year. Put your own tariff into that sum before deciding.
Some households also charge a battery from the grid overnight on a cheap tariff and use it at the evening peak. That can be worth more than storing solar, but it depends on a time-of-use tariff, and the rates change.
Sizing it
- Look at your smart meter or bills for use between about 4pm and 8am. That, not the panel size, sets the useful battery size.
- Allow for the battery's usable capacity, which is usually a little under its headline capacity.
- Do not size a battery to soak up a June day's surplus: it will sit part-empty from October to March.
- Ask whether the inverter can run the house in a power cut. Many cannot without an extra switch.
Fitting one in a Southport house
Batteries go indoors or in a weatherproof spot outside, usually near the consumer unit. In an older house with the meter in a cellar or under the stairs, the location and cable run are worth discussing at the survey. Ask where the installer proposes to put it and why: a garage, utility room or outside wall is usually a better home for a battery than a hallway or a bedroom. The installer must tell SP Energy Networks, the local network operator, about the combined system before or after connection depending on its size; see from quote to switch-on.
Installed in a home, batteries are zero-rated for VAT until 31 March 2027, whether fitted with panels or on their own later. From 1 April 2027 the rate is 5%.
Read on
Sources for this page
- Ofgem: price cap rates by region
- HMRC Notice 708/6: zero-rated VAT on installed solar and batteries
- European Commission JRC: PVGIS 5.3 solar output model
- SP Energy Networks to Ofgem (October 2020): SP Manweb serves Merseyside and North Wales
- Ofgem: the Smart Export Guarantee explained
- Ofgem: decision on typical household energy use (May 2026)
Questions about batteries
Do I need a battery with solar panels in Southport?
No. Panels work without one, and many homes are better off starting without. A battery earns its keep when the panels make much more than you use in the day and you are out or using little until the evening.
What size battery suits a Southport home?
Size it to what you use between late afternoon and the next morning, not to the panels. For many homes that is 4 to 10 kWh. A bigger battery sits part-empty for half the year, because in winter the panels rarely fill even a small one.
Can I add a battery later?
Yes. If you might, ask for a hybrid inverter or confirm that an AC-coupled battery can be added. Batteries installed in homes carry 0% VAT until 31 March 2027, with or without new panels.
Does a battery qualify for the Warm Homes: Local Grant?
Check with the scheme when you apply. Its measures are chosen to raise a home's energy rating, and solar PV is the measure most often listed; batteries are not always included.
Want a second opinion on your roof or a quote?
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