Grid-connected photovoltaic solar panels convert sunlight into electrical energy, unlike Solar Thermal panels which use the sun’s energy to heat water. Depending on how much power you use, your budget, and your roof space, you can generate enough power for all of your energy requirements. Any surplus energy produced by the panels can be fed back into the national grid and your power company pays you for it.

The biggest benefit of PV Solar is that you are effectively fixing your power price for the next 25 years. Since your power company will not pay you as much as they charge you for power, anything you feed back into the grid should be seen as a bonus rather than part of your investment decision. This means you need to size your system based on power you can use, rather than the amount of power you can export back to the grid. There’s a lot of variation in the buyback rates of power suppliers. We’ve asked around and can give you a fair idea when you contact us.









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Photovoltaic Solar in the Southern Lakes

The Queenstown region rates in the top 4 areas of the country for savings per annum with solar PV. Our high annual average daily solar irradiation (4.0kWh/sqm – the same as Nelson) coupled with our comparatively high cost of grid-supplied electricity (we pay some of the highest rates/kWh in the country) makes pv solar a great option for us to significantly reduce our power bills. Consent is not required by the QLDC for PV solar panels.

A 3kW system will generate around 3,800kWh per year in Queenstown (assuming no shading) which is just under half the average annual household power usage.

Is PV suitable for my house  ∨

Installing PV solar is one of the best energy saving decisions you could make but it isn’t suitable for everyone. We live in a mountainous region so it’s going to be important to factor in what time the sun dips down behind the hill at your house. Consider the following points or chat to us about what system would work best for you.

Size your system correctly. Oversizing will not only mean more costs upfront, but since the power companies do not pay you as much as they charge you for power the biggest financial benefits are gained by using the pv generated power yourself. To find out what size system you might need read your meter to work out how much power you use on average between 9am and 4pm (peak sun hours). And if you want to know what our local electricity retailer buy-back rates are, check them here.

Shading is bad for pv panels. Make sure there is little or no shading on your roof between the peak sun hours of 9am-4pm. Our new AC micro inverters can minimise the effect of shading as only the shaded panels stop producing electricity while the others continue to work (compare this to traditional DC systems in which if one panel is shaded they all stop working)

Check your roof is suitable (if that’s where the panels are going). You need to allow around 7sq.m per kilowatt installed. Not only that, but since the panels have a lifetime typically around 30-40years, you want to know your roof is in a condition that it won’t need to be replaced before the panels do.

Greatest savings come from using the pv generated power at the time it is made, so get smart about ways to use appliances during the peak sun hours. Talk to us about ideas such as timers on appliances etc.

How do I maximise my return on investment  ∨

The real key to financial returns is to use the electricity generated by the pv panels at the time it is being made. Without getting too technical, here’s why:

You buy electricity from your power company at around 31cents per unit. As the solar panels make electricity, any appliances that are ‘on’ in your home will use that electricity at the time, saving you 31cents for evey unit of electricity they use. If the panels make more electricity than can be used it is sold back to your power company for much less than the 31cents they charge you for theirs. (Depending on who you choose the value can range from around 5cents to 18cents/unit).

Trouble is, the typical NZ household uses 25% of its power in the morning and 40% between the hours of 5pm-8pm, not during the peak sunshine hours. During these times you have to buy back the electricity you sold to your power company (for 18cents during the day when you weren’t using it) at their rate of 31cents!

So you can see it makes for a much better investment if you can use as much pv generated electricity as possible. For households and businesses where the building is occupied during the day this isn’t a problem, but if  you’re not, here are a couple of simple ways to easily increase pv power consumption:

  • Timers and delay settings. Most modern dishwashers, washing machines etc have a ‘Delay’ setting so all you need to do is delay the start for 2hrs after you walk out the door for work. Timer switches on appliances like freezers, having your hot water cylinder on ripple control etc will have the same effect.

  • Instead of North-facing panels you could have a split East/West orientation. Although you would generate around 10% less electricity than a North facing system over the course of a year, the value of the electricity will be much higher as instead of paying 31cents/unit you will be using you own electricity and a lot less power will be exported back to the grid for 10cents.

Which PV panels do you use  ∨

We won’t compromise on quality. High quality pv systems are safer, produce a higher power output and last longer. We won’t install cheaper, low quality systems as we don’t want to have to come back and fix them – it’s that simple.
We use TRINA SOLAR panels with ENPHASE AC micro-inverters – the world’s leading and most efficient micro-inverter.


What is the difference between AC and DC PV systems  ∨

AC solar modules are the future of photovoltaic solar. Traditional PV Solar systems use standard solar panels which connect to an inverter via DC wiring. AC modules differ in that each solar panel has its own AC micro-inverter pre-installed. This offers the following key advantages over traditional DC systems:

Unlike traditional DC-based string/central inverters which have a high DC voltage of up to 600V running through their DC cables, AC systems are much safer due to the internal DC voltage being only that of a single PV module.

AC micro-inverter systems take up to to 50% less time to install when compared to string based DC systems. As micro inverters are integrated onto the solar modules and arrive at a job site ready to install, no DC cabling in conduit is required, significantly reducing installation cost and complexity.

The micro inverter is highly reliable as it is designed to operate from -40C to +85C, achieves a peak efficiency of 94.1% and has a 25 year life expectancy to match solar panels. Compare this to a typical 5 year warranty on a DC inverter. Micro inverters are more dependable through the elimination of the central inverter, which typically requires replacing at least once in a system’s lifetime.

Micro inverter solar systems boast higher average long term electricity yields up to 25% more than conventional DC solar systems. This is due to a number of reasons including:
(a) shade tolerance and fault redundancy as explained above,
(b) individual Maximum Power Point tracking (MPPT) of each solar panel,
(c) lower de-rating of output power at high temperatures,
(d) less down-time due to higher system reliability,
(e) lower operational DC input voltages, meaning that at first light the micro inverters will produce power long before a conventional
central string inverter will. Similarly at last light.

Internet based, the system owner is able to log on from anywhere and view the performance of each and every single solar panel on their roof in real-time. The installation company as well as the inverter manufacturer are also able to do this. Technical support is therefore readily available and any faults are relatively easily detected. In a conventional DC solar system, any suspected fault with a solar panel may result in an electrician having to disconnect and test each and every solar panel in order to find any fault.

The system size is not dictated by the capacity of a wall mounted string inverter, allowing for additional panels to be added at any time and only limited by your roof space and budget.

Unlike conventional DC solar systems, the design for micro inverter solar systems is relatively simple and flexible. Solar panels with micro inverters can be positioned to face several different directions in the one installation, and at several different tilt angles without any system limitations, making the design quite straightforward. For split level, multi-gabled, multi-angled, and multi-pitched rooves, this design flexibility can mean the difference between having no system at all installed, and a well working micro inverter solar system.

What are the electricity retailer buy-back rates  ∨

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Show me some actual electricity generation from local installations  ∨

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