Battery chemistry & storage
Enter your capacity, cycling frequency, and electricity rate. Compare full lifecycle cost per year, capital plus efficiency losses, across six chemistries.
How it works
Step 1
These two numbers drive both the capital cost per year and the efficiency loss cost per year, so getting them close to your real usage matters for the whole comparison. The round trip efficiency comparison isolates that efficiency piece if you want a closer look.
Step 2
A higher rate makes efficiency differences between chemistries matter more in the final total.
Step 3
Installation labor, balance-of-system components, and maintenance still vary by chemistry and installer. Use the cost per kWh comparison if you want to check a specific quote against typical rates too.
Sticker price and cost per kWh only tell part of the story, since they ignore how long a battery lasts and how much energy it wastes to inefficiency over its life. Combining capital cost per year with efficiency loss cost per year gives a fuller, apples-to-apples figure for comparing chemistries that differ wildly on both dimensions, similar in spirit to how the DOE's Office of Electricity evaluates storage technologies on lifecycle cost rather than sticker price alone.
LFP's combination of long cycle life, high round trip efficiency, and moderate upfront cost keeps both cost components low relative to other chemistries, covered from the cycle-life angle alone in the daily cycling comparison. That combination is difficult for most other chemistries to match once both cost factors are considered together, and if that moderate upfront cost is still more than you want to pay at once, the financing for battery addition calculator works through how spreading that payment changes the picture.
A chemistry that wins on total cost of ownership for daily cycling may not win for light backup use, since capital cost per year depends heavily on how quickly cycle life gets used up, a usage-dependent tradeoff NREL's energy storage research models across a range of duty cycles rather than a single assumed pattern. Rerun this comparison at your actual cycling frequency rather than assuming daily-use results apply universally, and check the best chemistry for backup only use comparison if your usage looks closer to that pattern.
Installation labor, racking, wiring, permitting, and ongoing maintenance all add real cost that varies by chemistry, installer, and region, none of which is captured here. The balance of system costs in particular can shift meaningfully between chemistries with very different footprints and mounting requirements. Treat this as a strong starting comparison between chemistries, then add your project's specific costs on top, checking the quick comparison tool for a fast sanity check across other factors too.
Questions
This comparison combines two cost components into one yearly figure: capital cost per year, which is the upfront purchase price spread across the battery's projected years of service, and efficiency loss cost per year, the ongoing cost of energy wasted to round trip inefficiency. Together they give a fuller picture than either sticker price or cycle life alone.
LFP typically comes out lowest or near-lowest in total cost of ownership for daily-cycling systems, combining a long cycle life with high efficiency and moderate upfront cost. For a 10 kWh system cycled daily, LFP's total cost of ownership might run around $326 a year, compared to well over $2,000 a year for lead acid under the same conditions.
Lead acid's low sticker price gets overwhelmed by its short cycle life once you spread that cost across only a year or two of daily-cycling service, and its lower round trip efficiency adds further ongoing cost on top. Total cost of ownership exposes that combination in a way a simple price-per-kWh comparison misses.
No, it focuses on capital and efficiency costs specifically, and leaves out installation labor, balance-of-system components, insurance, and any maintenance costs that vary by chemistry and installer. Use it as a strong starting comparison between chemistries, then layer in project-specific costs for a complete budget.