Project Overview

Commercial solar NZ installations don’t get more practical than this. KFC Papatoetoe operates a high consumption commercial kitchen running through long trading hours every day of the week – exactly the kind of business profile where on site solar generation delivers immediate and sustained impact on energy costs. Future Energy designed and installed a 19.95kW commercial solar system across the Cavendish Drive rooftop in December 2025, pairing 42 Longi Hi MO X10 panels with a Sungrow SG20RT three-phase inverter to deliver clean, reliable generation that matches the site’s peak daytime demand.

The Challenge

Commercial kitchens are among the most energy intensive businesses in New Zealand – refrigeration, cooking equipment, ventilation, and lighting all running simultaneously, all day. For a site like KFC Papatoetoe, energy costs are a significant and largely unavoidable part of operating expenses. With rising electricity prices and a roof well suited to solar generation, the business case for commercial solar NZ was clear: generate electricity on site during peak trading hours and reduce reliance on grid power at the times it costs the most.

The installation needed to work around an active commercial site – precise planning, minimal disruption, and a system that could be commissioned and producing from day one. The corrugated iron roof required engineered mounting, and with a 200A HVAC switchboard and 400A mains supply on site, the system was designed to integrate cleanly with the existing electrical infrastructure.

The System

42 × Longi Hi MO X10 LR7-54HVH 475M Panels – 19.95kW Total

42 Longi Hi MO X10 475W panels were selected for this commercial solar installation, delivering a combined array capacity of 19.95kW across two south west facing sub arrays at 3 degree tilt. The Hi MO X10 is Longi’s flagship commercial grade PV solar panel, featuring BC cell technology with up to 24% module efficiency, less than 1% first year power degradation, and 0.35% annual degradation from year two – meaning the system maintains strong output across its full 25 year product warranty period. With a 30 year linear power warranty and TUV, IEC, and CSA certifications, the Longi panel is purpose built for commercial solar power systems where longevity and performance consistency matter.

Sungrow SG20RT – 3 Phase Commercial Inverter

The Sungrow SG20RT is a 20kW three phase multi MPPT string inverter designed specifically for commercial solar NZ and commercial scale applications. With two independent MPPT inputs handling the split 18 panel and 24 panel sub arrays across the roof, the inverter optimises generation from each array section independently – maximising output despite the dual array configuration. The SG20RT achieves up to 98.5% efficiency, includes built in Type II DC and AC surge protection, 24/7 live monitoring via Solar Analytics connected to the site’s mains 400A controller, and carries a C5 anti corrosion rating suited to the Auckland urban environment. The inverter is wall mounted on the roof block wall, keeping the installation clean and accessible.

Dual South West Array – Engineered for the Site

The 42 panel array is split across two south west facing sections at 245 degrees azimuth – SW1 carrying 18 panels at 8.6kW and SW2 carrying 24 panels at 11.4kW. A 500mm access gap runs through the middle of the array as required by the PV plan, with 500mm clearance maintained from the gutter line. DC cabling runs surface mounted on the roof with no cable tray, connecting to the Sungrow inverter before feeding into the HVAC switchboard AC connection. Solar Analytics monitoring is live from commissioning, giving the site real time visibility of generation performance.

System Specifications

• 19.95kW nominal PV array – 42 × Longi Hi MO X10 475W panels
• Sungrow SG20RT 20kW three-phase inverter with dual MPPT
• SW1: 18 panels at 8.6kW – SW2: 24 panels at 11.4kW, both at 245° azimuth, 3° tilt
• Max DC voltage: 757.7V – Max DC current: 30.06A
• AC output: 3-phase, 20kW max, 31.9A – connected to 200A HVAC switchboard
• Solar Analytics monitoring connected to 400A mains catch controller CTs
• Smart meter installed – full generation and consumption visibility from day one

Frequently Asked Questions

Is commercial solar a good investment for a fast food restaurant?

Yes – and commercial kitchens are particularly well suited to it. Fast food restaurants typically trade during daylight hours when solar generation is at its highest, meaning on site generation aligns closely with peak consumption. Rather than exporting surplus at a low rate, the solar energy goes directly into running the site. For a business with high, consistent daytime energy use like KFC Papatoetoe, commercial solar NZ delivers a strong return from day one and compounds over the 25 year life of the system.

How does a 3 phase inverter differ from a standard residential inverter?

A three phase inverter like the Sungrow SG20RT is designed for commercial solar power systems connected to a three phase electrical supply – standard for commercial premises in New Zealand. It distributes solar generation evenly across all three phases, handles significantly higher power outputs (20kW in this case), and is engineered for the reliability demands of commercial operations. For a site like KFC Papatoetoe with a 200A HVAC switchboard and 400A mains supply, a three phase commercial inverter is the correct choice.

Can commercial solar be installed without disrupting an operating business?

Yes. Future Energy regularly installs commercial solar NZ systems on active commercial sites. Careful project planning, sequenced installation, and close coordination with site management means most commercial solar installations can be completed without disrupting trading hours. At KFC Papatoetoe, the system was designed and commissioned with minimal footprint – surface run DC cabling, roof mounted inverter, and a clean AC connection to the existing switchboard.

What monitoring comes with a commercial solar system?

This system includes Solar Analytics monitoring connected to the site’s mains 400A catch controller CTs – providing real time generation data, consumption tracking, and performance reporting from commissioning. A smart meter is also installed, giving complete visibility of grid import, solar generation, and export. For commercial operators, this data is valuable not just for tracking savings but for understanding energy patterns and identifying further efficiency opportunities across the site.

Looking at commercial solar NZ for your business? Future Energy designs and installs commercial solar systems across New Zealand – from single site commercial installations through to multi site rollouts. Talk to us about what the right commercial solar power system looks like for your operation.