Payback results
Net investment
£0
Simple payback
0 years
Inflation-adjusted payback
0 years
Verdict
—
10-year total savings
£0
20-year total savings
£0
Sensitivity check
Methodology
How payback is calculated
Simple payback is net investment divided by annual net savings, where annual net savings equals energy bill savings minus any increase in annual maintenance costs. Inflation-adjusted payback compounds the annual savings by the selected energy price inflation rate and finds the year in which cumulative savings exceed the initial net investment.
The 10-year and 20-year figures are cumulative gross savings minus maintenance effects over those periods. This is still a simplified planning tool: it does not include financing cost, discount rates, component replacement cycles, or degradation.
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