How a home battery works
A home battery stores electricity to use later. With solar panels, it captures surplus generation during the day that would otherwise be exported, then supplies your home in the evening. Without solar, it can charge from the grid on a cheaper off-peak rate and discharge when prices are higher.
Most domestic batteries use lithium iron phosphate (LFP) chemistry, which is stable and suited to daily cycling. A battery management system controls charging, temperature and safety automatically, so day to day there is nothing for you to do.
What gets installed
- 1
Battery unit
Wall or floor mounted, usually in a garage, utility room or outside in a weatherproof unit. It needs ventilation and space for access.
- 2
Inverter
A hybrid inverter shared with solar (DC-coupled) or a dedicated battery inverter (AC-coupled).
- 3
Energy monitoring
A current clamp and app that show what your home, panels and battery are doing in real time.
- 4
Optional backup circuit
A changeover switch that keeps selected circuits running during a power cut, if your system supports it.
- 5
Network notification
Batteries count as generation, so your installer notifies or applies to SP Energy Networks or SSEN.
What affects the cost of a battery
Usable capacity
Measured in kWh. More storage costs more, but it only adds value if you can regularly fill and empty it.
Inverter arrangement
Fitting at the same time as solar is often simpler than retrofitting to an older system.
Backup power
Emergency or whole-home backup needs extra switchgear and wiring.
Location and cabling
The distance between the battery, inverter and consumer unit affects labour and materials.
Solar pairing
With solar, the battery size should match your typical surplus, which a survey can estimate.
Your tariff
Time-of-use tariffs change how much value you get, but not the installation price.
Who benefits most from a battery?
Households that are out during the day but use a lot of electricity in the evening tend to benefit most, especially with solar panels. Homes with an electric vehicle, a heat pump or electric heating can also make good use of off-peak charging. If you already use most of your solar power as it is generated, a battery adds less, and a good installer will tell you so.
Common questions
Can I add a battery to my existing solar panels?
Usually, yes. A battery can be AC-coupled to an existing system with its own inverter, or connected through a replacement hybrid inverter. The right option depends on the age of your current inverter and your fuse board. A survey confirms which route is simpler and better value for your home.
Is a battery worth it without solar panels?
It can be. On a time-of-use tariff, a battery charges from the grid when electricity is cheapest and powers your home at peak times. Whether it pays off depends on your tariff, how much electricity you use and when. An honest survey should model this with your own bills.
Will a battery keep my power on during a power cut?
Not automatically. Most home batteries switch off during a power cut for safety, unless the system includes backup or emergency power output. If backup matters to you, perhaps because you live rurally and outages are common, ask for it at the quote stage, as it changes the wiring.
What size of battery does a Scottish home need?
Many Scottish homes suit a battery of around 5 to 13 kWh, but the right size comes from your evening usage, any solar generation and your tariff. A battery that is too large rarely fills, and one that is too small runs out early. Bills and usage data give the best answer.
Last updated: 17 October 2026