Energy · Decision Engine
Should I add a battery?
A battery is at least five decisions stacked on top of each other. This engine starts with the job you actually want it to do, then works the maths from there.
Home batteries are sold as one product answering one question, and priced accordingly. In practice they answer five: keeping the lights on in a cut, capturing solar you'd otherwise export, shifting demand into cheap overnight windows, covering an EV, or simply buying continuity you'd rather not do without.
The right hardware, the right size and the right tariff each depend on which of those jobs is really the primary one. Pick the job below and the recommendation follows honestly; including the cases where the honest answer is "not yet" or "not this one".
Pick the one that matters most; the others still shape the reasoning below.
Pick the primary job above and the recommendation appears here. Nothing is submitted until you save it.
The reasoning appears here once the engine has read your answers.
If this were our house
We'd almost never recommend a battery on a flat tariff with no solar. The maths just doesn't work; the arbitrage window that makes a battery earn its keep only exists on a smart tariff, and the self-consumption story only exists once solar is on the roof.
Where a battery genuinely is the answer, we'd size it around the primary job and pair it with a hybrid inverter if backup matters at all. Two of those decisions are hardware choices made once; the tariff is the lever you keep pulling every year afterwards.
Add this decision to your Home Brief
A saved decision is a decision you can act on ; the Brief is what you or an installer will refer back to.
Complete the read and the answer above to unlock the save.
Where next in Energy.
Solar, batteries and EV charging are one decision in three parts. The path below is the order that keeps the maths honest.
- 01
The problem
Name the bill, the peak, or the hunch that brought you here.
- 02
Why solar doesn't power a blackout
The mechanism most homeowners find out only after installation.
- 03
Should I add a battery?
Start with the job the battery is doing, not the payback in isolation.
- 04
Energy references
Solar, home batteries and EV charging; the honest picture on each.
- 05
Supporting guides
Tariffs, export limits, inverter sizing, install pitfalls.
- 06
Case studies
Real UK homes and the shape their energy stack settled into.
- 07
Projects
What a good solar-plus-battery install actually looks like.
- 08
Vetted installerComing
Matched quotes from installers who work to this standard.