ROI Calculator
Estimate Your Potential Energy Savings & Payback
Enter the figures for your proposed project to calculate an illustrative annual saving, fan running cost and simple return on investment.
£
Enter only the energy spend affected by the
proposed fan project.
%
Use a project-specific assumption supported by
the building assessment.
Include all fans expected to operate in the
assessed mode.
W
300 W is an editable example and should be
replaced with the expected project figure.
hrs
Use the expected annual operating schedule after
controls and occupancy are considered.
£
/kWh
Replace the example with your actual electricity
tariff.
£
Include fans, controls, installation, access
equipment, electrical work and other relevant
project costs.
Planning estimate only.
This calculator provides a simple annual illustration.
It does not include finance costs, inflation, tariff
changes, tax, maintenance, downtime, weather
normalisation, residual value or every project-specific
cost and benefit.
Illustrative Annual Result
Your Planning Estimate
Gross Avoided Energy Cost
£20,000
Annual spend multiplied by the assumed
saving percentage.
Fan Electricity Cost
£150
Fan quantity × power × annual hours ×
electricity price.
Estimated Net Annual Saving
£19,850
Gross avoided cost minus estimated fan
electricity.
Simple Payback
1.0 years
Installed project cost divided by estimated
annual net saving.
Average Monthly Net Saving
£1,654
Estimated annual net saving divided by twelve.
Five-Year Simple Net Benefit
£79,250
Five years of net savings minus the initial
project cost.
£50,000 × 40% = £20,000 gross saving.
1 fan × 0.300 kW × 2,000 hours × £0.25/kWh =
£150 fan electricity.
Estimated net annual saving: £19,850.