Infratec -Solar PV Mini-grids in the Cook Islands

Infratec_Island_Farm.jpgInfratec is delivering an Asian Development Bank funded project to deliver solar PV mini-grids on four of the Southern Group of Cook Islands – Atiu, Mangaia, Mauke and Mitiaro.

The mini-grids will supply each island with approximately 95% of their electricity needs, with an installed capacity of 1.3MWh of solar and 7.3MWh of battery storage.

The systems will reduce diesel consumption by about 360,000 litres annually, will remove about 960 tonnes of CO2 emissions a year and will supply the islands’ residents with a more reliable power supply.

Infratec is engaging Cook Islanders to support delivery throughout the project and building the capacity of local communities to support ongoing maintenance and operations of the systems.

The project will be completed by December 2017.

Introducing PowerSprout

Globally we manufacture and export the Powersprout brand of hydro turbines, hydro pumps and solar powered water pumps.

Freenergy Solar - Charging Dave's EV with Solar

Dave's home solar system is charging his EV during the day and you won't believe how much he is saving!

Freenergy Solar - Retrofitting Batteries

Optimising the home owner’s existing solar system for self-consumption

Retrofit an existing string system with an appropriately sized Enphase AC battery and Envoy gateway communication device to capture excess power generation for self-consumption

Radical reduction in grid-supplied power, minimal electricity bills "Self-Reliant" Target

Roger had an 8 panel, 2kw string inverter system and a hot water cylinder diverter (controller) installed by Freenergy in January 2015. Though Roger’s power bills were reduced after his initial installation he was finding his solar production during the day was more than he could use. Excess electricity was being exported to the grid during day (at 8c/kWh) and he was drawing electricity from the grid at night (at 33.33c/ kWh) – a sad deal no matter how you look at it.

Roger knew at the time of his PV install he wanted to be as self-reliant as possible, but the price point of the batteries on the market at the time meant it was not economical for Roger as a small residential system owner. Other batteries on the market were not appropriate for his residential system, installing a 5-8kw battery and paying upwards of RRP $9,000 NZD for another brand of battery was not financially viable - Roger would have been paying for excess battery capacity which his system simply would never use. The Enphase 1.2Kw battery was the perfect fit for Rogers 2kw system and at a much lower price point of RRP 2,500NZD.

In December of 2016 Roger contacted Freenergy, to design a system to optimise his self-consumption and reduce grid reliance through batteries that would power his house long after the sun went down.

Solar Energy After Dark
The Enphase AC Battery knows when the PV System is producing more power than what is being consumed and stores this energy ready to be used in the evening once the solar system is no longer producing power. Coming in modular 1.2kW plug and play blocks, the battery is much more suitable for smaller systems like Roger’s than the other oversized and complicated to install batteries on the market. The 1.2kW storage capacity the Enphase AC Battery is the perfect size for Roger's needs, but if he were to increase his system size, more batteries can be easily added to accommodate increased production.

Adaptable to Local Utilities Pricing Structures
Roger has also found the software of the Enphase AC Battery can be programmed to optimise it’s behaviour to suit the local utility’s requirements. With the recent Time-Of-Use pricing structures being implemented by New Zealand lines companies, the Enphase AC battery works seamlessly to discharge stored, free solar energy during the evening and also set up to charge from the grid during cheap off-peak times to help manage your high peak morning loads.

Retrofitting PV Systems with Enphase Batteries
“The great thing about Enphase products is that they are compatible with other brands, so it’s easy to upgrade an old string inverter system with Enphase monitoring and batteries”. Freenergy Solar Solutions are customer focused and spend time understanding each customer’s usage pattern, so they can design a solution that suits their customer’s individual needs. Aaron says he doesn’t favour one brand of inverter or battery over another and instead he simply chooses the best solution to suit his customer’s specific needs. Although Aaron does not sell Enphase exclusively, he says most of his residential installs use Enphase products, and many of his existing string customers are now upgrading to install an Enphase battery with advanced monitoring capabilities. “Expandability, future proofing - Enphase adds value to new and existing solar systems because their products are smart, versatile and allow for cost-effective expansion as technology evolves". 

Independent Power - Off-grid Power Supply Motukiekie Island


  • Remote 30 hectare private island with no mains power available
  • Existing off-grid system had been out grown and was starting to fail
  • Batteries were at the end of service life with some failed cells.
  • 3 x solar arrays of various ages
  • Numerous generator failures


  • Removal of old arrays and installation of new PV arrays.
  • Installation of new Outback FPA3, 48volt 9kW system
  • Install new Juice Lithium battery bank
  • Install new generator
  • General tidy up of existing AC distribution board and cabling


  • New fully compliant system
  • System reliability
  • Increased capacity of both storage and output
  • The upgraded PV array with greater generation was well suited to the high charging current of the lithium batteries
  • Remote monitoring now available


“When asked to upgrade the power system on a remote off grid island, the Outback products were an easy choice for this project as they offered proven reliability, and when coupled with the Outback OpticsRE remote monitoring feature, they are the obvious choice for a remote location.

The timing of the project meant we had the option of the new Outback FPA prewired system. We selected the FPA3. The installation was simple and quick, and knowing you are installing a fully compliant NZ system with the correct isolation and protection devices, was important to us, not to mention the time saved onsite.

The FPA system’s design allowed ample room for our incoming and outgoing cables and the option for future expansion should it be needed. From the property owners perspective, the system is very neat and the Mate 3 home screen offers the owner the information they want at a glance. Also, the intuitive function of the Mate3 allows for easy navigation should it be needed.”

Shane Pratley


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McNae Electrical Solutions Solar PV and Battery Case Study

This is what Dr David Wilde from Foxton Beach had to say about his solar and battery installation...

"I first became interested in solar generation several months back, the main drivers being an escalating bill for supplied electricity, a large house, and living in an area with relatively high sunshine hours. Other considerations were an interest in electric vehicles with the opportunity of utilising renewable energy, and a general concern for the welfare of the planet.

Solar Inverters on garage wall. It is not in my nature to rush these decisions, and so I carefully researched the available options, and asked many many questions. While there is a great deal of information available via numerous websites, McNae Electrical Solutions were particularly helpful in facilitating this process, and allowing me to obtain unbiased and independent information to enable a decision.

As there are basically two main types of inverter systems currently in use, and numerous options for battery storage, (in my view an essential component of any PV system ), it was important to choose a system in which all components were compatible, additions could be made seamlessly, and performance monitoring was intuitive and user-friendly. Hence the decision to choose the Enphase system, using microinverter technology, and the Enphase AC batteries.

McNae Electrical Solutions were not only very competitive with their pricing, but had the advantage of being a well established local company, experienced in solar installations, and with very knowledgeable and approachable staff.

The installation of the system presented some challenges for the electricians, who made an excellent job of running cables almost invisibly, and fitting the batteries without compromising aesthetics.

The company has been very professional in their approach to supplying and installing this system, and I am very pleased with my decision to engage McNae Electrical Solutions for this project."

Powersmart Solar - Vunabaka Resort Fiji

Vunabaka resort is typical of many of the projects that we work on, in that years worth of work have gone into it before anything seems to happen. This is a project that is at the cutting edge of solar PV projects and uses the best technology sourced from all over the globe. 

In 2012 we were approached by some developers who wanted to build a beautiful resort in Fiji, but like many Pacific islands there was the major issue of electricity. Their solution at that stage was to do multiple off grid homes and lodgings all with their own solar power system and battery back up. While great in theory, we quickly realised that there were major inefficiencies in doing it this way and so came up with a suggestion modelled off what we had done in Tokelau but with a twist.

PowerSmart solution was to create a minigrid using multiple solar arrays all feeding into a single centralised battey bank that powered a reticulated grid that all the buildings were connected to. There a number of advantages to doing this:

  • With multiple arrays orientated in different directions a more constant supply of electricity is possible throughout the day
  • A centralised battery bank helps to eliminate inefficiencies compared to having individual batteries on each home
  • Because all the electricity generated by the solar PV is fed into a centralised pool of electricity, individual houses on the development can be charged for electricity. This gives the developer or manager of the resort another income stream.

In October 2016 Stage One was completed with over 300kW of solar PV panels and 2 Megawatt hours of Tesla industrial battery storage (Tesla powerpack). This is all backed by PowerSmarts own proprietary monitoring and control programme which ensures a constant supply of electricity to the grid.

This project also won 'Best Solar PV Off Grid Implementation' at the annual SEANZ (Solar Electricity Association of New Zealand) Awards in November 2016

Skysolar - Muriwai Golf Club

“We’ve officially entered the technological revolution! Thanks, SkySolar, great work and a fantastic feature for our Golf Club.”


That's what Muriwai Golf Club had to say about their new solar installation by SkySolar.


Installation Details:
Power Output: 3kW
Panels: 12 x Canadian Solar 250W
Inverter: Fronius 3kW
Customers: Muriwai Golf Club
Location: Muriwai Beach