About Battery Payback

What Battery Payback does

Battery Payback compares one battery quote with the same home and existing solar system without a battery. You provide:

• the installed battery quote;
• electricity purchase and export prices;
• additional annual costs;
• operating and time assumptions; and
• three first-year delivered-energy scenarios.

The calculator does not select a battery, predict the home’s consumption or create an energy forecast.

How the comparison works

One consistent set of prices, costs and operating assumptions is applied to the Lower, Central and Higher delivered-energy scenarios. The comparison isolates the additional battery investment from the existing solar system and estimates its cash-flow effects across the selected analysis period.

Calculations use full internal precision. Displayed currency, energy and payback values are rounded separately for readability.

Open the calculator to review or change the assumptions.

How to read the results

• First-year net saving is the first year’s avoided electricity purchase cost minus lost solar export income and additional annual costs. It is not an average annual saving over the operating life.
• Net present value is the present value of modeled net cash flows over the selected analysis period, discounted at your real annual return target, minus the upfront investment. Meeting the target applies only to those assumptions and that period; it does not promise an achieved return.
• Sustained payback is the earliest modeled annual boundary, starting at installation time (year 0), at which undiscounted cumulative net cash flow is non-negative and remains so through the end of the analysis period. The separate interpolated payback estimate assumes savings accumulate evenly during the payback year. An earlier crossing can be lost later, sustained payback may not occur within the period, and remaining non-negative through that period does not guarantee it remains non-negative afterwards.
• Maximum upfront cost is the largest non-negative additional investment that meets the model’s NPV target at your real annual return target over the selected analysis period. Some scenarios have no non-negative cost that meets the target. It is not a market value or purchase-price recommendation.

Lower, Central and Higher refer only to user-provided delivered-energy scenarios. They are not recommendations, rankings, confidence intervals, guaranteed best, expected or worst cases, or forecasts of actual household behaviour. Use them to examine how different assumptions affect the estimate.

What the model includes

The estimate uses the additional installed upfront cost of the battery, first-year AC energy delivered from the battery to the home, the corresponding solar energy diverted from export, electricity purchase and export prices, whole-system AC efficiency, additional annual costs and the user’s annual decline assumption.

It also uses the selected analysis period, assumed operating life and real annual return target. Optional capacity, warranty and annual import or export information can support visible checks and context; they do not create an extra financial benefit.

What the model does not decide

The calculator does not predict actual household energy use, future electricity prices, battery ageing outside the entered model assumptions, actual operating life, installation quality, operational feasibility, warranty outcomes or equipment failures.

It does not automatically include:

• hourly or dynamic tariff optimisation, grid charging, or reserve and grid-service revenue;
• financing costs, subsidies or taxes;
• backup-power value, replacement cost, residual value or a separate end-of-life cost; or
• installation changes outside the quote, insurance effects or property-related effects.

The calculator page remains the authoritative visible source for the current included and excluded model boundaries.

Decision support, not advice

Results are estimates based on your inputs. They are not:

• a savings promise;
• a payback promise;
• a return promise;
• a purchase recommendation;
• individual electrical, safety, tax, legal or investment advice.

Privacy and analytics

No account is required. During normal calculator use, the financial and technical values you enter are handled in the current page and are not intentionally sent to Battery Payback as analytics data. Reloading starts with an empty calculator.

Cloudflare Web Analytics is enabled for aggregate website usage and performance analytics. That analytics layer is separate from the calculator’s financial input handling. Read the privacy details.

Operator and contact

Battery Payback is operated by Fluidified, a business registered in Finland.

Operator

Fluidified

Country

Finland

Finnish business ID

2900573-7

Email

[email protected]

Questions, error reports and development suggestions can be sent to [email protected].