Home Battery Payback
Calculator
Results
- Break-even (years)
- 9.67251 yr
- Net position at the horizon
- $3,838.29
- Total savings
- $10,338.29
- First-year saving
- $645.00
- Energy shifted per year (kWh)
- 3,000 kwh
Cumulative cash flow crossing zero at break-even
- Cumulative cash flow
- Cumulative cost of doing nothing
- Cumulative cost with the upgrade
Year-by-year cash flow until break-even
| 1 | 645.00 | 645.00 | -5,855.00 | 1,020.00 | 6,875.00 |
| 2 | 651.06 | 1,296.06 | -5,203.94 | 2,049.59 | 7,253.53 |
| 3 | 657.18 | 1,953.25 | -4,546.75 | 3,088.85 | 7,635.61 |
| 4 | 663.36 | 2,616.61 | -3,883.39 | 4,137.89 | 8,021.28 |
| 5 | 669.60 | 3,286.20 | -3,213.80 | 5,196.79 | 8,410.58 |
| 6 | 675.89 | 3,962.09 | -2,537.91 | 6,265.64 | 8,803.54 |
| 7 | 682.24 | 4,644.34 | -1,855.66 | 7,344.53 | 9,200.20 |
| 8 | 688.66 | 5,332.99 | -1,167.01 | 8,433.57 | 9,600.58 |
| 9 | 695.13 | 6,028.12 | -471.88 | 9,532.85 | 10,004.72 |
| 10 | 701.66 | 6,729.79 | 229.79 | 10,642.46 | 10,412.67 |
| 11 | 708.26 | 7,438.05 | 938.05 | 11,762.49 | 10,824.45 |
| 12 | 714.92 | 8,152.97 | 1,652.97 | 12,893.06 | 11,240.10 |
| 13 | 721.64 | 8,874.60 | 2,374.60 | 14,034.26 | 11,659.65 |
| 14 | 728.42 | 9,603.02 | 3,103.02 | 15,186.18 | 12,083.15 |
| 15 | 735.27 | 10,338.29 | 3,838.29 | 16,348.93 | 12,510.64 |
Comparison
| Scenario | Total cost over the horizon | Cumulative energy cost | Net position at the horizon |
|---|---|---|---|
| Do nothing | 16,348.93 | 16,348.93 | 0.00 |
| With the upgrade | 12,510.64 | 12,510.64 | 3,838.29 |
Formula
saving(n) = capacity × cycles × (1−d)^(n−1) × (peak − offpeak/η) × (1+g)^(n−1)= 9.67
Note
This is a simplified cash-flow model. It projects the prices, escalation rate and equipment costs you entered with a single geometric escalation and no discounting, no inflation adjustment, no financing costs and no tax treatment; savings are assumed to accrue evenly within each year, which is what the fractional break-even interpolates. Real energy prices, tariff structures, grants, weather, occupancy and equipment performance vary widely and change over time. A break-even of zero means the cumulative cash flow never crosses into positive territory within the horizon you chose. Get a professional energy assessment and a written quotation before committing to any of these measures.
More in Energy payback
See all →Frequently asked questions
How does the calculator determine battery payback?+
It compares the battery's installed cost to the value of the energy it lets you store and use later, such as shifting solar power to evening use or avoiding peak electricity rates.
Why is home battery payback often longer than solar panel payback?+
Batteries are more expensive per unit of value delivered and degrade over charge cycles, so the savings per year are typically smaller relative to the upfront cost than with solar generation alone.
Does backup power value count toward payback?+
This calculator estimates purely financial payback from energy arbitrage or self-consumption; the value of backup power during outages is real but not something with an easy dollar figure, so it isn't included by default.
How does time-of-use pricing affect the result?+
If your utility charges more during peak hours, a battery that stores cheap off-peak or solar power for use during expensive hours captures more savings per cycle, shortening payback significantly compared to a flat-rate plan.
What if my battery is paired with solar panels?+
Combined systems should be evaluated together: the battery's payback depends on how much surplus solar energy it stores rather than sending back to the grid, so use the marginal cost and savings from adding the battery to an existing solar setup.