Operate
State of Health: the number that decides ROI
Nameplate capacity is what you bought. State of Health is what you still have. The gap between them is your return, quietly leaking.
A battery is the only major asset on a solar-plus-storage site that gets worse every time you use it. Capacity fades, internal resistance rises, round-trip efficiency slips. None of it is visible if you only watch power flowing in and out. You can run a pack that looks fine on a dashboard while it has quietly lost 8% of the capacity you are still paying finance on.
State of Health (SoH) makes that visible. By tracking measured capacity and efficiency against the design model — the pack as it was engineered — Attral shows you the real trajectory: how fast a pack is aging, whether it is on track for its warranted life, and which sites are degrading faster than they should. That turns two vague fears into decisions you can defend: warranty claims backed by evidence, and end-of-life or second-life planning based on data instead of a gut call.
SoH is not a vanity metric. On a financed asset, it is the difference between the returns you modelled and the returns you actually get.