See what rooftop solar could save you
Enter your electricity bill and roof area. We’ll size a system and estimate generation, savings and payback — with every assumption shown, so you can adjust it.
- Recommended system size
- Year-1 savings and payback
- 25-year net savings and IRR
Your site
Advanced assumptions
Cumulative savings over 25 years
Indicative estimate only. Real results depend on a site survey, roof orientation and shading, equipment, financing and your electricity provider’s rules. Subsidies, tax benefits and financing costs are not included. This is not an offer.
Get a detailed proposal
Send us this estimate and our engineers will survey the site and prepare a proper design and quotation.
Chat on WhatsApp insteadTransparent, adjustable assumptions
- Units from billMonthly units = bill ÷ tariff, unless you enter units directly.
- GenerationkWp × peak sun hours × 365 × performance ratio.
- System sizeThe smaller of what your load needs (at your chosen share) and what your roof area allows, rounded to 0.5 kWp.
- SavingsUnits used from solar × your tariff, rising each year, less yearly O&M.
- Surplus powerGeneration above your consumption is valued at the rate you set (default zero).
- DegradationOutput falls slightly every year, as set in advanced assumptions.
- InverterOne inverter replacement in year 12, as a percentage of system cost.
- Payback & IRRPayback is when cumulative savings equal the cost; IRR uses the 25-year cash flows.
- CO₂Grid emission factor of about 0.82 kg CO₂ per kWh.
About this calculator
How accurate is this estimate?
It is a planning figure. A site survey refines it using your roof layout, shading, orientation and your actual tariff structure.
Are subsidies or tax benefits included?
No. Government schemes and tax treatment vary by consumer category and change over time, so they are left out. We can advise during the proposal.
What if my roof is small?
The calculator limits the system to what your roof can hold. Ground-mount or carport options may be possible; talk to us.
What happens to surplus power?
It depends on your electricity provider’s net-metering rules. By default the calculator values surplus at zero, which is conservative.
Can I see a design instead of an estimate?
Yes. Use the form to request a site survey and a detailed proposal.