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Home & UtilitiesGenerated accuracy model review: 2026-05-06

Home Energy Savings Planner accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • Monthly savings = usage * rate * reduction + other savings. Payback = net upgrade cost / monthly savings.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • Monthly Usage: 950 kWh
  • Electric Rate: 0.18 $/kWh
  • Expected Usage Reduction: 18%
  • Upgrade Cost: $4,200
  • Incentives / Rebates: $900
  • Other Monthly Savings: 15 $/mo

Expected outputs

  • Monthly Savings: $45.78
  • Net Upgrade Cost: $3,300.00
  • Payback: 72.08387942332897

Known limitations

  • This workflow is a planning aid. Validate assumptions, rates, legal/compliance obligations, vendor quotes, and local policies before acting.

Assumptions

  • All values are user-entered planning assumptions.
  • Calculations run locally in the browser.
  • Saved artifacts are stored only when a signed-in user explicitly saves them.

Unit handling

  • Monthly Usage accepts values in kWh.
  • Electric Rate accepts values in $/kWh.
  • Expected Usage Reduction accepts values in %.
  • Upgrade Cost accepts values in $.
  • Incentives / Rebates accepts values in $.
  • Other Monthly Savings accepts values in $/mo.
  • Monthly Savings is displayed as currency.
  • Net Upgrade Cost is displayed as currency.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Currency outputs are displayed with standard US dollar formatting.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current home-energy-savings-planner calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Home Energy Savings Planner.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

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