Case Studies
The following cases are real-life examples shared by many New Zealand users on the well-known forum Reddit. These excerpts are provided for your reference to help you understand the actual benefits of solar energy and the market price situation.
I installed a 5 kW system without a battery last August. It cost $10,800, and my bills for the past two months have been around $30. I also upgraded the inverter because I plan to add a battery. We also hope to add an additional 5 kW of panels, so I'll have a 10 kW system. Of course, it depends on personal use. If you like using heat pumps, dryers, running multiple desktop computers, large refrigerators, ovens… yes, more panels would be better.
— Reddit user Sharpinthefang
8.7 kW grid in Queenstown. My bill for December to January was -$80, and from January to February, it was -$90. This is more than $300 less than our usual summer electricity expenditure of $250.
— Reddit user KiwiSparkie
I spent $11,000 on a 3 kW system without a battery. No gas or wood burner. My total electricity bill for 2023 was about $400.
— Reddit user alastairgbrown
*My parents installed a 5 kW solar system with a 5 kW battery. Their bills are usually negative in the summer and may be $5-60 per month in the winter. About three years ago, their typical winter bills were close to $300. It’s great and saves them a lot of money. They run the heat pump during the day to cool the house, etc. Also, the Contact Energy Goodnight plan, which they use to charge the battery 100%, has been a huge help!
I also installed a hot water cylinder timer for them. The cylinder has two ways to heat itself. If there’s excess energy during the day, it heats the HWC to temperature, and from 9 PM to midnight, it’s at full power. This alone saves a huge amount of money because the HWC accounts for more than one-third of your monthly bill.*
— Reddit user Raynoszs
We installed solar with a plan to break even in 7 years, but it happened sooner—about 4-5 years. We heat the water at noon since we don’t have gas, and we avoid gas pipeline fees, saving a lot of money. Our summer electricity bill is negligible, and the highest winter bill is $250. We also charge the car. Hope this helps!
— Reddit user getyourtambourine
I have a 7.2 kW system on my roof, a 10 kW battery, a 5 kW battery, 2 hot water timers, and a single-phase power supply. The system cost me about $30,000 a few years ago. I love my system—it kept basic operations running during Cyclone Gabrielle (7 days without power). Now, my annual electricity bill is about $100.
— Reddit user jdorjay
*I bought solar mainly for backup power because the grid here is unreliable. The 10 kW system, 6 kW hybrid inverter, and 13 kWh backup battery cost $40,000. However, it has also reduced my bills. In summer, on sunny days, I generate about 30-50 kWh per day and send the surplus to the grid. Winter is a struggle—I may only generate about 10 kWh a day. I use the battery in the morning to avoid peak rates, and I pay for power during the afternoon peak because I want to save battery power for outages. I don’t sell much back to the grid in winter—maybe 20-40 kWh per week, compared to 80-120 kWh per week in summer.
For my household usage pattern, we roughly estimate that winter bills will be about 25% lower than before using solar, and summer bills will be 50-90% lower. So, yes, it’s great, but it won’t pay for itself within ten years. But I didn’t install it to save money—I got it so I can keep working during power outages.*
— Reddit user PaddyScrag
My parents installed a solar system, and they are very satisfied. They opted for a system without a battery because they are retired and actually use it during the day. This saved them a lot of money on the system, which will pay for itself in about five years.
— Reddit user lakeland_nz