Which way the roof faces
North is the best case and is what the estimate assumes. East–west splits still work well. They spread generation across morning and evening instead of piling it into the middle of the day, but the annual total is lower.
What Could SolarSave You?
Start with your power bill. Two clicks gives you an indicative system size, a first-year saving and a payback period, on Canterbury numbers.
Want your exact numbers? We will model your actual roof properly.
Request a Quote
Reading the result
Four things that moveyour number the most
The calculator uses Canterbury averages. These are the four variables that pull a real quote away from the estimate, in roughly the order they matter.
What shades it
A chimney, a neighbour's poplar or a power pole can cost a surprising amount of output, because shading one part of a string can drag the rest down with it. We map it on site, which no calculator can do.
Your actual tariff
The estimate uses 34c/kWh and a 12c buy-back. Your retailer's rates, your fixed daily charge and whether you are on a time-of-use plan all change the answer: sometimes materially.
When you use power
The single biggest lever, and the one you control. Solar you use yourself is worth the full retail rate; solar you export earns the buy-back. Running the dishwasher at noon is worth real money: a battery, or an EV charging on surplus, more again.
Paying for it
The payback number assumesyou pay cash
Most of our residential jobs are not funded that way. Every major New Zealand bank now lends for solar at rates far below a standard mortgage, several at 1% or interest-free, so if you have equity in your home the repayments are often close to what the power bill already was.
Want the real numbers for your roof?
A free on-site assessment turns the estimate above into an itemised quote.
Or reach us directly on 021 849 627 · office@energon.co.nz