| 10.92kW Solar Array | 41.2kWh/day Est Production | 4yrs 6mths Payback | $4,591 Year 1 Savings |
Project Overview
Solar installation NZ projects don’t always fit neatly on a single roof face, and this home in Silverdale, Auckland needed a system split across two orientations to make the most of the available roof. With daily consumption running at around 40kWh, Future Energy designed a 10.925kW solar array using 23 bifacial panels, projected to produce an estimated 41.2kWh a day. The system is projected to cut the annual power bill from around $6,570 to roughly $1,980, delivering $4,591 in savings in year one, with the investment paying for itself in 4 years and 6 months.
The Challenge
With daily consumption of around 40kWh, well above a typical household, Sajin needed a system sized to genuinely offset a substantial power bill, not just take the edge off it. The roof itself added another layer of complexity, with no single face large enough or well oriented enough to carry the full array, meaning the system had to be split across two different orientations while still performing as one cohesive system.
The System
Dual Orientation Bifacial Array at 10.925kW
The system uses 23 x Longi LR7 54HVD 475M bifacial panels for a combined array output of 10.925kW, split across two roof faces, 14 panels facing northeast at a 46 degree azimuth and 23 degree tilt, and 9 panels facing northwest at a 316 degree azimuth and the same 23 degree tilt. Splitting the array this way spreads generation across more of the day rather than concentrating it all around midday. The panels use a double glass, gridless design that generates power from both sides of the cell, and carry a 25 year materials and processing warranty plus a 30 year linear power warranty, guaranteeing at least 88.85% of rated output after three decades.
SolaX X1 SMART 10K G2 Inverter
A SolaX X1 SMART 10K G2 inverter, rated at 10kW AC output, uses 3 independent MPP trackers to manage the two roof orientations as separate strings while feeding a single combined output. The inverter carries a 10 year warranty and includes 24 hour consumption monitoring through the SolaX cloud interface.
The Results
- 10.925kW solar array installed across 23 bifacial panels, split across two roof orientations
- Estimated 41.2kWh produced a day, closely matched to around 40kWh of daily household consumption
- Year 1 savings of $4,591, with payback in 4 years and 6 months
- Annual power bill projected to fall from around $6,570 to roughly $1,980
- Estimated solar export earnings of $1,733 a year from surplus generation sent back to the grid
- 25 year materials and processing warranty plus a 30 year linear power warranty on the solar panels, and a 10 year warranty on the inverter and installation
Two roof faces, one system, one much smaller power bill.
Frequently Asked Questions
What are bifacial solar panels and are they worth it?
Bifacial panels generate power from both the front and back of the cell, capturing reflected light off the roof as well as direct sunlight, for a small gain in output compared with standard panels. They also use a double glass, gridless design that gives a cleaner, more uniform look, which was part of the appeal for Silverdale installation alongside the extra generation.
Can a solar system be split across two different roof orientations?
Yes. this Silverdale system uses 14 panels facing northeast and 9 facing northwest, managed through an inverter with multiple independent MPP trackers so each orientation performs at its best rather than being limited by the weaker performing face. Splitting an array like this can also spread generation more evenly across the day.
How much solar do I need for a household using around 40kWh a day?
Based on this Silverdale installation, a 10.925kW array was sized to produce an estimated 41.2kWh a day, closely matching that level of consumption. Higher use households generally need a larger array and more roof space, which is why Future Energy models actual usage data before recommending a system size.
What warranties come with this solar installation?
This installation includes a 25 year materials and processing warranty and a 30 year linear power warranty on the Longi bifacial solar panels, guaranteeing at least 88.85% of rated output after 30 years, plus a 10 year warranty on the SolaX inverter and a 10 year installation warranty.
Got a roof that doesn’t fit a standard solar layout, or a high daily power use? Future Energy designs solar installation NZ systems around your actual roof and consumption data, including multi orientation and bifacial panel options. Get in touch for a free quote.
