Battery Cost per kWh — What Storage Actually Costs
"Battery cost per kWh" is the price you pay for one kilowatt-hour of storage capacity. But there are two very different numbers behind it — the bare cell price and the fully installed system price — and neither alone tells you whether a battery pays off. This page gives you both, plus the number that decides economics: cost per kWh cycled over the battery's life.
Battery cost per kWh comes in two forms. (1) The cell/pack price — what the raw lithium-ion cells cost — which for large-scale lithium-iron-phosphate (LFP) packs has fallen into the roughly €100–150/kWh range in recent years. (2) The installed system price — cells plus inverter, enclosure, wiring, cooling, safety and labour — which is much higher: typically a few hundred €/kWh for large grid-scale projects and higher for small home systems. When someone quotes "battery costs X per kWh," always ask which of these two they mean.
Four factors move the number: (1) Scale — a multi-MWh grid battery buys cells and hardware far cheaper per kWh than a single home unit. (2) Chemistry — LFP is cheaper and longer-cycling; NMC is more energy-dense but pricier. (3) What's included — bare cells vs. a turnkey installed system with inverter, safety and grid connection. (4) Market timing — cell prices have trended down over years but move with raw-material and demand cycles. A single "€/kWh" figure without these details is close to meaningless.
A low purchase price per kWh is worthless if the battery only lasts a few hundred cycles. Divide the installed cost per kWh by the number of full charge/discharge cycles the battery is warranted for to get the levelised cost per kWh throughput. Illustrative arithmetic: an €800/kWh installed system rated for ~6,000 cycles works out to roughly €0.13 per kWh cycled (€800 ÷ 6,000) — before financing, efficiency losses and O&M. This cost-per-cycle figure, not the sticker price, is what you compare against what the battery can earn.
Storage pays for itself by buying energy cheap and selling (or self-consuming) it expensive. Stromfee measures that upside directly from live day-ahead prices. Over one recent 30-day window the Belgian day-ahead spread averaged about €162/MWh — roughly 16 ct per kWh cycled and 136% of the average price. In Lithuania the 30-day spread was about €126/MWh (146% of the average). When the value captured per kWh cycled exceeds your cost per kWh cycled, the battery earns its keep — capacity payments (e.g. CRM) and balancing income (FCR/aFRR) stack on top.
A residential home battery and a utility-scale BESS live in different price worlds. Home systems carry high fixed costs (installation, small inverter, retail margins) spread over few kWh, so their €/kWh looks steep. Grid-scale batteries dilute those fixed costs across MWh and buy hardware at wholesale, so their installed €/kWh is a fraction of a home unit's. Comparing a home quote to a grid-scale headline number is apples to oranges — benchmark within the same class.
Ask four questions: Is this the cell price or the fully installed price? How many warranted cycles (and to what remaining capacity — usually 70–80%)? What round-trip efficiency (typically ~85–95% for lithium-ion)? And what can it realistically earn per kWh cycled in your market? Only when you have installed cost per kWh, cycle life and expected revenue per cycle can you judge whether a battery is cheap or expensive — the raw €/kWh alone can't.