# Solar Lifetime Cashflow Worksheet

Model annual savings, degradation, maintenance and a one time replacement.

[Open this tool](https://whatson.pk/lifecycle-calculator/)

Category: Solar & Battery

Solar savings and expenses can change across the system's lifetime. A yearly worksheet makes later costs visible.

Choose the horizon and enter degradation, maintenance, discounting and replacement timing. Compare annual and cumulative figures under those assumptions.

## Inputs and controls

* Initial cost (PKR). Allowed range: 0 to 1000000000000
* Study horizon (years). Allowed range: 1 to 50
* Annual discount rate (%). Allowed range: 0 to 50
* First year gross savings (PKR/year). Allowed range: 0 to 1000000000000
* Annual savings degradation (%). Allowed range: 0 to 99
* Fixed annual cost (PKR/year). Allowed range: 0 to 1000000000000
* One time replacement cost (PKR). Allowed range: 0 to 1000000000000
* Replacement year (0 means none) (year). Allowed range: 0 to 50

## How to use

* Enter initial cost, study horizon and annual discount rate.

* Enter first year gross savings, annual savings degradation, fixed annual cost, one time replacement cost and replacement year (0 means none).

* Select Calculate result. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

A replacement cost appears in its chosen year instead of being hidden inside a constant annual payback figure.


## Before relying on the result

Discounted cashflow from user assumptions, not a financial recommendation. Savings degrade from year two; no tariff escalation or salvage is assumed. Replacement must fall within the horizon or be disabled.


## Tool limitations

Discounted cashflow from user assumptions, not a financial recommendation. Savings degrade from year two; no tariff escalation or salvage is assumed. Replacement must fall within the horizon or be disabled.

## Questions

### Is the cashflow a guaranteed return?

No. It depends on entered assumptions. Tariff changes, financing and unmodelled costs can alter actual results.

### What should I check before using Solar Lifetime Cashflow Worksheet?

Check Initial cost, Study horizon, Annual discount rate and First year gross savings. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-01T18:56:36+00:00

This profile describes the tool. It does not execute it or supply a professional certification.