Free assessment

Christchurch estimate

Solar savings calculator

See roughly what solar would cost for your home and what it could save you, with and without a battery. No sign-up, no contact details.

Tell us your electricity bill or usage

Enter either, or both for a more personalised estimate. Use an average across summer and winter, electricity only.

kWh
When does your household use most of its electricity?

Think about heating, cooking, hot water and larger appliances.

Would backup power during an outage be useful to you?

Backup needs a compatible battery and the right installation.

How we work this out
  • Your usage: if you enter kWh, we use that. If you only enter a bill, we take off a $2 daily charge and divide the rest by 33c per kWh. If you enter both, we use your kWh and work out your own average rate from the bill, which is an average across the day, so less exact on time-of-use plans.
  • Prices: real installer pricing for a typical single-storey Christchurch home with a metal roof, as of October 2026, shown as a range because every installer and every home is different.
  • Solar output: each kW of panels makes about 1,250 kWh a year in Christchurch, with winter output around a third of summer’s. The indicative system size roughly matches your yearly use, between 3 kW and 10 kW. Payback changes little between nearby sizes, so an installer will size it properly for your roof. Both options use the same panel size.
  • When you use power: this sets how much of your solar is used in the home, roughly a quarter if mostly mornings and evenings, up to around 40% if mostly during the day. “Not sure” uses a cautious middle figure. These are our estimates, not measured for your home.
  • Exports: solar you don’t use is sold back at about 12c per kWh. Yearly benefit is the power you no longer buy plus these credits.
  • Battery: one reference battery of about 9 kWh usable, the same at every system size, without whole-home backup wiring. It’s worked out as an average day for each month, not real weather: it only stores solar your home isn’t already using, about 10% is lost between charging and using it, we allow for cloudy days when it won’t fill, and it can only cover power you’d otherwise buy. That’s why it does much less in winter. In our reference pricing a smaller battery was only about $1,000 cheaper and backup equipment about $1,400 more.
  • Backup: your answer only changes our suggestion, never the savings.
  • Payback: simple payback, the price divided by the yearly benefit. It doesn’t include power price rises, panel wear over time, finance costs or maintenance.

An estimate only, not a quote or financial advice.