When homeowners in Preston, Blackpool, or Burnley start looking at solar panels, they often ask whether to add a battery at the same time — or wait and see.
It’s a genuinely good question, and the answer isn’t the same for everyone. Here’s what you need to think through.
Why batteries matter for solar
Solar panels generate electricity when the sun is shining. For most households, peak generation is during the day — typically between 10am and 3pm — which overlaps only partially with when you actually use electricity at home.
Without a battery, any electricity you don’t use at the moment it’s generated gets exported to the grid. Under the Smart Export Guarantee, your energy supplier pays you for this — but usually at a rate of around 5–15p per unit.
The problem is that when you then need electricity in the evening, you’re importing it from the grid at the going rate — which has been anywhere from 25p to 35p per unit in recent years.
A battery changes this equation. Instead of exporting your surplus at 10p and buying it back at 30p, you store it and use it yourself. That difference in value is what makes battery storage financially worthwhile.
The case for getting both at the same time
There are a few practical reasons why doing solar and battery together in one installation makes sense:
• Installation costs are lower when done together. The labour involved in fitting an inverter, cabling, and commissioning the system is largely the same whether you add a battery or not — so doing it all at once avoids paying twice.
• You start maximising self-consumption from day one. Rather than spending a year exporting cheap electricity and waiting until you can afford the battery later, you’re getting the most out of your system immediately.
• Modern solar inverters and batteries are designed to work together. Retrofitting a battery to an existing solar installation isn’t always straightforward and may require additional hardware depending on the original setup.
• You may qualify for a single VAT rate across the whole installation, which is currently 0% for energy-saving materials including solar and battery systems.
When it might make sense to wait
There are situations where holding off on the battery initially is a reasonable call:
• Budget constraints. A solar-only installation might cost £4,000–£6,000 for a typical home, while adding a battery can push that to £8,000–£12,000. If cash flow is a concern, solar alone still delivers significant savings.
• You’re assessing first. Some homeowners prefer to see their actual generation data over a full year before committing to battery size — though in practice, a good installer can give you a very accurate forecast based on your roof and usage profile.
• Your usage pattern is unusual. If you’re home all day, work from home, or have an electric vehicle, you naturally self-consume more electricity during the day — so a battery adds less marginal benefit than it would for a household that’s out all day.
What size battery do you need?
Most home battery systems available in the UK today range from about 5kWh to 16kWh of usable storage. For a typical household in Lancashire, a 10kWh battery is a commonly recommended size — it’s enough to store a good proportion of a summer day’s surplus and cover most of an evening’s electricity use.
Larger batteries (13–16kWh) make most sense if you have a higher-than-average electricity demand, an EV you want to charge cheaply overnight, or if you want to maximise the ability to store cheap off-peak grid electricity as well as solar.
The right size really depends on your household usage patterns. Your installer should be modelling this based on your actual energy bills and usage, not just recommending the biggest battery on the shelf.
Smart charging and time-of-use tariffs
Modern battery systems can do more than just store solar electricity. Many can also charge from the grid overnight when electricity is cheapest (if you’re on a time-of-use tariff like Octopus Go or similar), and then discharge during peak evening hours when grid electricity is most expensive.
This grid-charging feature can be valuable even in winter, when solar generation is lower. Your battery might charge overnight at 7p per unit and discharge it when you’d otherwise be importing at 30p — saving money even on days when the sun barely makes an appearance.
The bottom line
For most homeowners in Lancashire who are serious about reducing their electricity bills and making the most of a solar installation, getting both panels and a battery together makes good financial sense. The combined payback period is longer than solar alone, but the ongoing savings are meaningfully higher.
If budget is the main constraint, solar-only is still a worthwhile investment — and you can retrofit a battery later, even if it costs slightly more than doing it all at once.
The most important thing is getting the system properly sized for your home and usage. Wise Energy Solutions works with homeowners across Blackpool, Preston, Burnley, and the surrounding areas to put together systems that genuinely make financial sense — not just the most expensive option.
📞 Get a straight-talking quote. Call Wise Energy Solutions on 01253804151 or visit wiseenergy.co.uk.