The year in Leeds, month by month
PVGIS gives the monthly output of panels angled for the best year-round result in central Leeds (PVGIS 5.3). For a 3 kW system, divided by the days in each month, it looks like this beside Ofgem's typical household use of 2,500 kWh a year, about 6.8 kWh a day (Ofgem):
| Month | Panels make | Typical home uses | Room for a battery |
|---|---|---|---|
| January | 3.6 | 6.8 | little |
| March | 8.3 | 6.8 | plenty |
| May | 11.2 | 6.8 | plenty |
| June | 11.0 | 6.8 | plenty |
| July | 11.0 | 6.8 | plenty |
| September | 8.7 | 6.8 | plenty |
| November | 4.3 | 6.8 | little |
| December | 3.4 | 6.8 | little |
From spring into autumn the panels produce more in a day than the home uses, and much of it arrives at midday when many households are at work or school. That is the surplus a battery holds back for the evening. In December and January the system makes a fraction of the day's use, so almost everything is used as it is generated and the battery has little to fill it.
A cheaper overnight tariff can give a battery a winter job, charging it from the grid at night to cover the evening peak. Whether that is worthwhile depends entirely on the tariffs available to you, so work it through with your own supplier's rates.
How big a battery
Size to the two numbers that limit what it can do: the surplus your panels leave on a good day, and the electricity you use between sunset and morning. A smart meter's half-hourly readings show the second; the table above gives a feel for the first. On the small roofs of many Leeds terraces the summer surplus is a few kWh, so a large battery would often sit part-empty. An east and west pair of slopes, which spreads output across the day, can also mean a smaller battery than a single south slope; see the roof picker.
The spread over the year is wide. At the best angle in the city centre each kW makes about 114 kWh in July and 35 in December (PVGIS 5.3). For a 4 kW roof that is roughly 14.7 kWh on an average July day against 4.5 in December, while Ofgem's typical household uses about 6.8 kWh a day all year (our arithmetic; Ofgem). That is why a battery bought to store panel output does most of its work between April and September. To price the panels alongside it, see the costs page.
Battery prices
DESNZ publishes median installed prices for batteries added to existing homes, by capacity (DESNZ):
| Capacity | Median per kWh | Example (our arithmetic) |
|---|---|---|
| Under 6 kWh | £1,300 | 4 kWh: about £5,200 |
| 6 to 11 kWh | £890 | 8 kWh: about £7,100 |
| 11 to 30 kWh | £630 | 12 kWh: about £7,550 |
Larger batteries cost less per kWh, so use the bands as a guide rather than a formula. Batteries installed in homes are zero-rated for VAT until 31 March 2027, then 5% (HMRC). Adding one with the panels avoids paying for scaffold and a visit twice; solar costs in Leeds covers the panels.
Northern Powergrid and storage
Northern Powergrid runs the network across Leeds. Its G98 route covers generation and storage up to 16 amps per phase, 3.68 kW on a single-phase supply, added up for the whole property: the installer connects and notifies the network within 28 days (Northern Powergrid). Because a battery inverter counts alongside the solar inverter, a modest system plus a battery can pass the limit.
Above it, the installer applies under G99 and waits for agreement before connecting, or designs the system with export limiting that the network accepts (Northern Powergrid). The quote should say which route applies; the grid connection guide explains both.
Finding a place for it
Where a battery goes is a fire-safety question. The British Standards Institution's PAS 63100 sets out where home batteries may and may not be installed, keeping them away from escape routes and sleeping areas, and an MCS installer should follow it (BSI).
That is easier in a semi with a garage or a side wall than in a terrace. A back-to-back has no rear wall or yard of its own, so the options are inside the house: a cellar where there is one and it stays dry and within the battery's temperature range, or a utility space off the escape route. Through-terraces may have a rear yard or outbuilding. Ask the installer to show you the spot before you sign, and why it meets the guidance.
The council grant and batteries
Leeds's Warm Homes: Local Grant lists battery storage when fitted with solar panels, for privately owned homes at EPC D to G with a qualifying household: income under £36,000, an income-related benefit, or a qualifying area. It was not taking new applications when we checked (Warm Homes Leeds). The funding page has the full rules.