Home battery storage
Store what you generate.
How batteries work, what size you need, when they pay off, and how they fit with solar.
How a solar battery works
What a solar battery actually does
Stores excess solar during the day
When your panels generate more electricity than you are using, the surplus charges the battery instead of being exported to the grid.
Powers your property in the evening
After the sun goes down, the battery discharges to cover your usage. You draw from stored solar rather than buying electricity from the grid.
Imports cheap off-peak electricity
On a time-of-use tariff, the battery can charge overnight at lower rates and discharge during peak hours, reducing what you spend on grid electricity.
Do I need a battery with solar panels
Solar with and without a battery
Solar without a battery
Generate during the day, use what you can
- Electricity you generate powers your property in real time
- Surplus you cannot use is exported to the grid
- You earn a payment for exports through the Smart Export Guarantee
- Lower upfront cost and a simpler system overall
- Still significantly reduces what you buy from the grid
Solar with a battery
Store the surplus, use it after dark
- Surplus charges the battery instead of going to the grid
- Battery discharges in the evening to cover your usage
- More self-sufficient and less reliant on grid pricing
- Higher upfront cost, longer payback period
- Can also charge from the grid overnight on cheaper tariffs
Neither option is wrong. It depends on when you use energy and how much you value independence from grid pricing.
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Start your solar journeyIs a solar battery worth it
What affects how useful a battery is
No two properties benefit in the same way. These six variables determine how much a battery actually helps.
When you use electricity
High evening users get the most value from a battery. If most of your consumption happens during the day while panels are generating, the benefit is smaller.
Solar system size
Bigger arrays generate more surplus. More surplus means more available to store. A small system on a north-facing roof may generate little excess worth storing.
Your export tariff rate
The lower your Smart Export Guarantee rate, the stronger the case for storing rather than selling. Storing surplus is worth more when grid export pays less.
Access to off-peak tariffs
Batteries on time-of-use tariffs can save money independently of solar by charging at low overnight rates and discharging during expensive peak periods.
Property type and usage pattern
Homes with consistent evening demand benefit more than holiday properties or buildings that sit empty most of the week.
Future plans for the property
Adding an EV or a heat pump significantly increases your evening electricity demand, which changes the return calculation for battery storage.
What size solar battery do I need
Battery sizes explained
Around 5 kWh
Entry level
Covers light evening use for a smaller household or one with modest overnight consumption. A starting point for those new to battery storage.
Around 10 kWh
Mid-sized household
The most common size for a typical UK home. Covers most evening and overnight use, with capacity to charge from the grid on off-peak tariffs.
Around 15 kWh
Larger home
Suited to homes with higher consumption, multiple occupants, or an EV that charges overnight from the battery rather than directly from the grid.
20 kWh and above
High demand or commercial
Multi-day backup capability, large properties with significant overnight draw, or commercial applications where energy cost reduction is a primary goal.
Every property is different. A survey works out the right size based on actual consumption, not generic averages.
AC coupled vs DC coupled battery
Two ways a battery integrates with solar
DC coupled
Hybrid inverter system
The battery and solar panels share a single hybrid inverter. Power from the panels flows directly into the battery as DC before being converted, which is more efficient than converting twice.
Best suited to new solar and battery installations being done at the same time. If you are starting from scratch, a DC coupled system is typically the cleaner and more cost-effective choice.
AC coupled
Retrofit system
The battery has its own inverter and connects to the AC side of your electrical system. It works alongside your existing solar inverter rather than replacing it.
Best suited to adding a battery to a solar system that is already installed. No need to replace existing equipment. More flexible in terms of compatible hardware.
Which type suits your property depends entirely on whether your solar is already in place.
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Start your solar journeyWhat is inside a solar battery system
The four main components, in plain English
The battery itself
Most modern solar batteries use lithium iron phosphate chemistry, known as LiFePO4. It is stable, safe at domestic temperatures, and has a long cycle life compared to earlier lithium formats.
Battery management system
The BMS is built-in electronics that monitor cell voltage, temperature, and charge state. It protects the battery from overcharging, deep discharge, and thermal stress.
Inverter or hybrid inverter
Converts power between DC and AC as electricity moves between the battery, your property, and the grid. In a DC coupled system this is a single hybrid unit. In an AC coupled system the battery has its own dedicated inverter.
Monitoring app
Shows generation, consumption, battery state of charge, and grid import and export in real time. Most modern systems provide this via a smartphone app linked to the inverter.
How long does a solar battery last
What to expect over the life of a battery
Battery storage is a long-term addition to a solar system. Understanding how it ages helps set realistic expectations for the full ownership period.
Warranty period
Most modern solar batteries are warrantied for 10 years. This covers both failure and capacity retention, typically guaranteeing the battery holds at least 70 to 80 percent of its original capacity at the end of the term.
Beyond the warranty
Most batteries continue working well after the warranty period ends. Capacity reduces gradually over time rather than dropping suddenly. You will notice a slow decrease in how much it stores, not an abrupt failure.
What affects degradation
Cycle count, depth of discharge, and temperature all play a role. Systems that regularly discharge fully and charge quickly tend to degrade faster than those operating in a shallower cycle range.
Technology trajectory
Battery technology has improved significantly over the past decade and continues to do so. Systems installed today use more stable chemistry and smarter management than those from five years ago.
Do solar batteries work in a power cut
Power cuts and backup capability
Not all solar batteries provide power during a grid outage. This is one of the most searched questions about home battery storage, and the answer catches people out.
Standard battery installations remain connected to the grid and shut down automatically during an outage for safety reasons. Backup capability requires specific battery models that support islanding, plus additional hardware such as a backup gateway or automatic transfer switch.
Most domestic installs do not include backup by default. If power cut resilience matters to you, it needs to be specified at the design stage, not added later.
If this is important for your property, mention it when you get in touch. It changes the equipment specification.
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Start your solar journeyWhere do you install a solar battery
Where batteries get installed
Common install locations
- Utility rooms, garages, and lofts are the most common locations for home battery storage
- Most batteries need a dry, ventilated space with a stable ambient temperature
- Outdoor-rated battery options exist for properties where no internal space is available
Physical size
- Wall-mounted units are roughly the size of a small wardrobe panel
- Floor-standing units are similar in footprint to a slimline fridge
- Most modern batteries are designed to be unobtrusive in a domestic setting
A technical survey identifies the best location based on your property layout, the position of your consumer unit, and where the inverter sits.
Common questions
Battery storage FAQ
Ready to take the next step
Design a battery system for your property
If you know your property type, the audience pages below give a more detailed picture of what a system looks like for your situation. If you want to talk it through first, call or email directly.
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