About 506 kWh in June and about 139 kWh in December: that is what PVGIS, the European Commission’s solar model, gives for a 4 kWp array facing due south at 35° in Petersfield. The same roof, the same panels, and well over three times the output in midsummer. If you are thinking about a battery, that seasonal gap matters more than the annual total, and it is the honest starting point for our page on home battery storage in Petersfield.
Petersfield’s annual figure, about 4,128 kWh from 4 kWp on the same run, is among the highest of any town page on this site. A high annual number can make it tempting to buy the biggest battery on offer. The monthly figures explain why that is usually the wrong instinct.
The four months that matter
| Month | PVGIS output, 4 kWp | Average per day (our arithmetic) |
|---|---|---|
| June | about 506 kWh | about 16.9 kWh |
| July | about 500 kWh | about 16.1 kWh |
| December | about 139 kWh | about 4.5 kWh |
| January | about 162 kWh | about 5.2 kWh |
December comes to about 27% of June, and January about 32% of July. Those ratios sit in the same narrow band as most of the towns we cover, so Petersfield’s advantage is real but modest: it shows up as more summer surplus, not as a different winter. All of these figures assume an unshaded roof facing due south; an east or west slope, or shade from trees or a neighbouring roof, would bring every month down.
What a battery does in a Petersfield June
Set those daily figures against use. Ofgem’s typical domestic consumption value from 1 July 2026 is 2,500 kWh a year, about 6.8 kWh a day on average. In June, an average day on a 4 kWp roof in Petersfield makes roughly two and a half times that. Some of the output is used as it is made; the rest either goes into a battery or is exported.
This is where a battery does most of its work. On a typical June day there is enough surplus to fill a 5 kWh battery and, for many households, a 10 kWh one, which then runs the house through the evening and overnight. The Energy Saving Trust suggests a typical home system might be 10 kWh, and a Petersfield June gives a battery of that size a realistic chance of filling on an average day.
What a battery does in a Petersfield December
In December the arithmetic turns over. About 4.5 kWh a day on average is less than the 6.8 kWh a typical household uses across the year, before any allowance for longer evenings with the lights on. Most of what the roof makes is used as it is made. There is little or nothing left to store, whatever the size of the battery.
That leaves two honest positions. A battery can sit largely idle in midwinter, which is fine if you sized it for the summer surplus. Or it can be set up to charge from the grid on a cheaper overnight tariff and discharge at peak times, which earns money only if your tariff gap is wide enough. Our post on battery storage without solar panels works through that tariff arithmetic, because in December a battery behind panels is doing much the same job.
Size to the evening, not the season
The Energy Saving Trust says there is no exact formula for sizing a battery. The monthly PVGIS figures for Petersfield suggest a sensible order of questions. How much electricity does your house use between late afternoon and the next morning? How much surplus does your roof make on a spring or autumn day, not just a June one? And would your tariff reward charging from the grid in winter?
A battery sized to the evening use of a Petersfield household will be full through much of the year and modest in winter, which is the realistic outcome. A battery sized to make the house self-sufficient in December would need a roof that makes far more in winter than a typical Petersfield roof does, and no battery size fixes that. Our guide to how solar battery storage works covers the rest of the sizing picture.
The local paperwork and advice
Petersfield’s town centre sits in SSEN’s Southern Electric Power Distribution licence area. Under G98, a system up to 16 A per phase (3.68 kW) is notified before commissioning or within 28 days of it; a larger one needs G99 approval before work starts. A battery’s inverter counts towards that total alongside any solar, which can tip a modest system into G99. Your installer handles the notification.
For impartial advice, Petersfield has its own environmental charity, PeCAN, which gives free home-energy advice across the town and surrounding villages. East Hampshire District Council has fitted 331 solar panels plus battery storage on its own Monterey House offices, and DESNZ records about 7,356 solar PV installations of every size across East Hampshire at the end of 2025, as first published. The roof side of the decision, including what the South Downs National Park does and does not change, is on our page on solar panels in Petersfield, and the county picture is on our Hampshire solar panels hub.
Sources: PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023, 4 kWp, 35°, due south, 14% losses, building-mounted; run 15 October 2026); Ofgem, Typical Domestic Consumption Values (from 1 July 2026); Energy Saving Trust, Battery storage (updated 19 August 2026); NESO GIS boundaries for GB DNO licence areas (May 2024) and SSEN, Who we are (read 15 October 2026); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); MCS, Notifying DNOs; Petersfield Climate Action Network (PeCAN), My Home Made Better; East Hampshire District Council, ‘New strategy sets East Hampshire’s climate priorities’ (2 August 2024); DESNZ, Renewable electricity by local authority 2014 to 2025 (29 September 2026); GPDO 2015 Schedule 2 Part 14, as amended by S.I. 2026/896.