Deck the Halls with Volts & Meters Electrotest’s Christmas Edition 🎄⚡

Options for testing Solar in New Zealand 

Jonathan Taylor

Solar in New Zealand is in the infancy of a gold rush like growth according to some sources. The numbers paint a picture: 

• In January 2021, NZ had 31,105 solar systems installed. By mid-2024, that number jumped to 62,707 systems, totalling 447.5 MW of capacity - almost halfway to a gigawatt 

• Average system size is growing, from 3.5 kW (2013-2019) to 4.9 kW today, driven by cheaper panels and the rise of EVs and home batteries 

• In 2009, a 3-kW system cost about NZ$40,000. Today, a 7-kW system averages NZ$16,500, a 60%+ drop 

Figure 1: Uptake of Grid Connected Solar Power Systems in New Zealand 
https://www.mysolarquotes.co.nz/blog/solar-power-industry-news/new-zealand-solar-market-stats-insights-2024/ 

​​​​​​​With this growth in the size of systems, the solar panel strings open circuit voltage and short circuit current have also been growing at a rapid rate. As with any electrical system this is going to require ongoing testing and maintenance. 

As solar systems have evolved, so have the required specifications of the equipment used to test these systems. The early equipment was low voltage, but now you can have solar arrays well in excess of 1000V DC and up to 40A short circuit current.  

This trend is predicted to continue as equipment design evolves. Therefore, a consideration must be made when looking for test equipment. In order to future proof your instruments, there must be head space to allow for predicted increases in open circuit voltage and short circuit current.  

For example, there is test equipment designed to do the following tests: 

• Open circuit voltage & short circuit current 

• Full I-V curve tracing  

• Insulation resistance  

• Earth continuity  

• DC operating current/power  

• String current (parallel strings) 

BUT only up to 1000V DC.  

Whereas you have other equipment that will do the same tests up to 1500V open circuit voltage and 40A closed circuit current on live panels. 

If you would like to contact us, we would be more than happy to go through the options with you. 

A Ray of Humour

Tip of the Month: This One Test Tells You If Your PAT Is Behaving 🧰

As part of using electrical test equipment, it’s good practice to carry out your own “sanity check” periodically, and not be reliant on the calibration status of it.

Here’s a quick check that will tell you three useful things about your Portable Appliance Tester in one test.

Connect a digital multimeter (set to 600/1000VDC range) to the neutral and earth slots of your PAT test socket and proceed with insulation resistance test. 

Three outcomes should be observed:

1. Both devices read anything at all – this means that as per AS/NZS 3760, live and neutral pins of EUT (Equipment Under Test) are shorted together and insulation resistance is measured from there to earth connection.
2. The DMM should give an approximate indication of applied insulation test voltage, it must not be less than 500VDC.
3. The PAT should give an indication of approximately 10MΩ which is the typical input impedance of most common digital multimeters.

This test is no substitute for calibration, however you may find it useful in the field if an unusual insulation resistance reading encountered.                             

Have any PAT Questions? Get in Touch With An Expert Today 

A VERY MERRY CHRISTMAS FROM ELECTROTEST TO YOU: LOOK AT THESE MEGA HOT SALES

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Key Information

Thank you for your support throughout the year! Please note our office will be closed from Friday, 19th December 2025, reopening on Monday, 5th January 2026.

Wishing you a Merry Christmas and a Happy New Year!