Solar first, or a battery?
Jason Hawthorne, CEO at ESME
Rates checked October 2026 · 5 min read · Last updated 22 October 2026
In short
It depends on your house. If you have an electric car and a cheap overnight tariff, a battery often earns more first, because it saves money every day of the year. If you are home in the day and your roof is good, solar often comes first. If you can, plan both together, because one inverter, one visit and no VAT until 31 March 2027 all save money.
For your house
Which comes first at your house?
Two minutes. You'll see your result on screen.
Key facts
Battery first suits
Homes with an electric car tariff and high evening use
Solar first suits
Homes busy in the day, with a good roof
Doing both
One hybrid inverter can run panels and a battery
VAT
None on either until 31 March 2027
Roof needs work?
Do the roof first, then solar
When does a battery come first?
A battery on a cheap overnight tariff saves money every day, winter and summer. With an electric car tariff at about 8p, each unit it moves saves around 17p. That steady saving often beats solar in a home with high evening use. See can you have a home battery without solar.
When does solar come first?
Solar comes first when you use a lot of power in the day, for example if you work from home, and your roof faces somewhere between east and west through south. It also suits homes that cannot get a cheap overnight tariff. See are solar panels worth it.
How do I plan for both?
- 1Ask for a hybrid inverter. It runs panels and a battery, so adding the second later is simpler and cheaper.
- 2Check the roof first. If it needs work soon, do it before the panels go on.
- 3Mind the VAT date. Batteries and solar have no VAT until 31 March 2027, then 5%.
- 4Get the network operator sorted. Panels and a battery together often need approval under G99 before they are connected, so allow time.
Questions people also ask
Can I add a battery to solar panels I already have?
Yes. A battery with its own inverter can be added to most existing systems.
Can I add solar to a battery later?
Yes, if the battery’s inverter can take solar, or with a second inverter.
Is it cheaper to fit both at once?
Usually, because the installer visits once and one inverter can do both jobs.
Sources
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Figures are for Great Britain and were checked on the date above. Prices change, so check the latest before you decide. This is general information, not financial advice.
Your house, not an average one
Want your order of steps?
Articles give you the general answer. Your journey gives you the numbers for your roof, your tariff and your car.
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