| 15 Panels 505W All Black | 7.575kW System Capacity | $137 CR Bill After 3 Months | 678kWh Exported in Feb Alone |
The Challenge
It started with a leaking gas califont that was nearing the end of its life. Rather than simply replacing like for like, this Queenstown homeowner took the opportunity to think bigger. The conversation quickly moved from hot water to whole home energy – and what it would look like to phase out gas entirely.
The home already had heat pumps for winter heating, so the logical next step was clear – switch to a hot water heat pump, add solar, and move everything to electric. With power prices continuing to rise, the homeowner wanted long term control over their energy costs rather than ongoing exposure to the grid.
The Solution
Solar Power System
Future Energy designed and installed a 7.575kW solar system featuring 15 x Suntech 505W dual glass all black panels, paired with a SolaX 6kW Boost inverter. The all black panels are both high performance and visually sleek – sitting cleanly on the roof of the two storey home. The system was installed across split arrays to maximise generation across the available roof space.
Hot Water Heat Pump
The leaking gas califont was replaced with a hot water heat pump – a far more efficient solution that runs on electricity rather than gas. With solar now generating power during the day, the heat pump draws on that free energy to heat water, dramatically reducing the cost of one of the home’s biggest energy demands. This also allowed the homeowner to completely phase out their gas connection.
The Right Export Plan
With a system generating well in excess of the home’s daily consumption, the homeowner signed up to an electricity plan with an attractive solar export rate. Rather than letting surplus energy go to waste, it flows back to the grid and earns a credit – turning the solar system into an ongoing revenue stream as well as a cost reducer.
The Results
Just three months after installation, the numbers speak for themselves. In February 2026 alone:
- The home used 121kWh from the grid – but exported 678kWh back to it
- The power bill came in at $137.31 in credit – the homeowner owes nothing and is building a surplus
- Gas has been phased out completely – the hot water heat pump handles all hot water needs
- All of this was achieved without a battery – the system performs on solar and a smart export plan alone
- As the system heads into its first winter, a battery remains an easy future addition to maximise overnight self sufficiency
| “You can have a zero dollar power bill in the summer months – even without a battery.” Future Energy, Lake Hayes Estate Installation |
Frequently Asked Questions
Can I really be in credit on my power bill without a battery?
Yes – and this installation proves it. If your system is sized correctly for your home and you’re on a plan with a good export rate, surplus solar energy earns you credits that offset your grid usage charges. In summer months especially, a well sized system can result in a zero or credit power bill with no battery required.
Is a hot water heat pump worth switching to from gas?
Absolutely. Hot water heat pumps are typically 3-4 times more efficient than gas califonts, and when powered by solar during the day, the running cost is minimal. Phasing out gas also removes your gas connection fee entirely, which adds up to meaningful savings over time.
What export rate should I look for?
Export rates vary between electricity retailers in New Zealand. It’s worth shopping around for a plan that offers a competitive solar buyback rate. Future Energy can point you in the right direction when we design your system, ensuring your setup is optimised to take full advantage of what you export.
Should I add a battery later?
A battery is a great next step if you want to maximise self sufficiency, particularly through winter evenings. The SolaX inverter installed in this system is battery ready, meaning adding storage in the future is straightforward. For now, the export plan does the heavy lifting – but the option is always there.
