Choosing a Solar Power Inverter
Written by
Kristy Hoare, Founder & Solar Market Research Specialist
Last updated:
Selecting a quality solar inverter is important; if an inverter fails the whole system will shut down.An inverter converts electricity from solar panels, DC through to AC. A small amount of loss can occur during this process. Inverter manufacturers specify a percentage of DC electricity that they can convert to AC electricity, often around 94%. Investing in an expensive inverter will be money well spent; higher quality inverters produce more yield of AC electricity and will last longer.
There are two types of inverters on the market today, string inverters and micro-inverters.
String Inverters
String inverters have been around a lot longer than micro-inverters. For a residential solar power system, a string inverter can be mounted on a garage wall or close to a switchboard. Cables connected to the solar panels run through wall cavities, through to the inverter.
The advantages of string inverters:
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They allow for flexible solar panel configuration
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They are highly efficient (94% to 97.8%)
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Economical
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3 phase power demand is possible
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Offer monitoring access at the inverter and remote access
Micro-Inverter
Micro-inverters (much smaller inverters) have been on the market since the 1990's, but only became competitive with string inverters in early 2010. One micro inverter is attached to the back of every solar panel installed and they perform the same function as string inverters. The main difference is that they convert DC electricity from just one panel into AC. An AC cable connects all the panels and sends the electricity through to your switchboard.
The advantages of micro-inverters:
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Inverter efficiency ranges from 95 to 96.5%.
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They run silent
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The micro-inverter will maximize each solar panels output, therefore panels will not need to be adjust to lower levels if other panels in the system are not performing. Therefore shading is less of an issue.
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Solar panels can be individually monitored for performance
View our comprehensive guides for:
Micro-Inverters Vs. String Inverters
Micro-Inverters Vs. Power Optimisers
What Are The Best Solar Inverter Brands In NZ?
When selecting a solar inverter in New Zealand, it's crucial to choose a brand known for reliability, efficiency, and local support.
There isn't a single best solar inverter brand in New Zealand, as each brand offers unique features. While some inverters are of higher quality, there are also economical options that are budget-friendly and perform well. Ultimately, the best choice depends on your specific needs and preferences. To help you decide, I've compiled a list of the top solar inverters available in New Zealand today.
Solar-Only Inverters
These inverters convert power from your solar panels. They don't connect to a battery.
Fronius Primo GEN24
3 - 6kW
97.6 %
2
Single
1
5.4/19 kg
530 × 474 × 165 mm
Upgrade the software to turn the Fronius GEN24 into the GEN24 Plus hybrid inverter at any stage.
Fronius Primo GEN24
8 - 10kW
97.3 %
2
Single
10 years
21 / 26 kg
595 x 529 x 180 mm
Upgrade the software to turn the Fronius GEN24 into the GEN24 Plus hybrid inverter at any stage.
Enphase IQ9N microinverter
427 VA per panel
97.95 %
NA (one per panel)
Single
25 years (with internet-connected IQ Gateway)
1.1 kg
214 × 176 × 30.8 mm
No
Hybrid Inverters
Hybrid inverters run your solar panels and a home battery from one unit. Choose one of these if you have a battery or plan to add one later.
Sungrow SH Series (SH-RS)
3 - 6 kW
97.4 - 97.7 %
2
Single
Sungrow SBR HV batteries
Yes
10 years
18.5 kg
490 × 340 × 170 mm
Sigenergy SigenStor EC (single phase)
5 - 12 kW
97.6 - 98.0 %
2 - 4
Single (three-phase version available)
SigenStor BAT 5.0 / 8.0 modules, stacked under the controller
Yes, whole-home, ~0 ms switchover
10 years
18 - 36 kg
700 × 300 × 245-260 mm
Sigenergy Sigen Hybrid SP2
3 - 6 kW
98.6 %
2
Single
SigenStor BAT modules (via SigenStor BC battery controller)
Yes, ~0 ms switchover
10 years
11.5 kg
373 × 473 × 99 mm
Sigenergy Sigen Hybrid TP2
5 - 12 kW
98.9 - 99.0 %
2
Three
SigenStor BAT modules (via SigenStor BC battery controller)
Yes, ~0 ms switchover
10 years
19.5 kg
477 × 568 × 99 mm
GoodWe ESA (EHA-G20)
3 - 10 kW
97.5 - 97.6 %
2 - 4
Single
GoodWe ESA battery modules (GW5.1 / GW8.3-BAT-D)
Yes, whole-home, under 4 ms
10 years
24 - 26 kg
800 × 300 × 270 mm
Pylontech Force H3X
3.6 - 15 kW
98 %
2 - 3
Single or Three
Pylontech FH10050 modules, stacked (1 - 7)
Yes, 10 ms or less
10 years
77 - 281 kg (with batteries)
540 × 665-1555 × 350 mm (stacked)
SolaX X1-IES
2.5 - 8 kW
97.6 %
2 - 3
Single
SolaX TP-HS50E modules, stacked (5.1 - 20.4 kWh)
Yes, under 10 ms
10 years
87 - 228 kg (with batteries)
730 × 908-1862 × 210 mm (stacked)
SolaX X1-VAST
5 - 10 kW
97.6 %
3 - 4
Single
SolaX lithium batteries (2 battery ports)
Yes, under 10 ms
10 years
28 kg
590 × 400 × 180 mm
AlphaESS SMILE-G3-S8
8 kW
2
Single
SMILE-G3-BAT-8.2P modules (8.2 - 49.2 kWh)
Yes, 20 ms or less
10 years
19.5 kg
610 × 366 × 212 mm
10 - 12 kW
97.6 %
3
Single
48 V low-voltage lithium or lead-acid (many brands)
Yes, on and off-grid
10 years
35.6 kg
420 × 670 × 233 mm
Solis S6-EH1P-L
3 - 6 kW
97.0 - 97.5 %
2
Single
Low-voltage lithium (multiple brands) or lead-acid
Yes, under 10 ms
10 years
20.3 - 22.4 kg
405 × 480 × 205 mm
Anker SOLIX X1 Hybrid (X1-H6K-S)
3.68 - 6 kW
97.4 - 97.6 %
2
Single
Anker SOLIX X1-B5-H modules (5 - 30 kWh)
Yes, under 10 ms
10 years
19 kg
670 × 335 × 150 mm
Entelar Energy EESOLAR-10KTL-LC0
10 kW
98.1 %
3
Single
EESTORE Battery System (5 - 30 kWh)
Yes, via compatible Backup Box
10 years
15 kg
425 × 376.5 × 150 mm
See how each panel is optimised with micro-inverters in the video below.
Inverter Warranties
Most string inverters have a warranty of 5 years. Paying more for a 10-year warranty is highly recommended. Micro-inverter warranties range from 10 years to 25 years.
Over-Sizing Inverters
An oversized inverter makes sense if additional solar panels are going to be added onto a system in the future. For example, you might install 3kW of solar panels and a 6kW inverter, allowing double the amount of solar panels to be added at a later date.
Be sure that the inverter is oversized within the inverter manufacturers recommendations. If not, the warranty will be considered invalid.
Undersizing Inverters
Some solar engineers may select an inverter that could be up to 15% smaller than your solar panel array size. For example, you have 5.5kW of solar panels and a 5kW inverter.
Reasons for under-sizing an inverter could include the fact that smaller inverters cost less, therefore you could save money with an undersized inverter, and performance may not be compromised.
Solar panels often operate below the nominal rated power amount, as optimal solar generation conditions do not occur frequently. Inverter efficiency is low when operating at low power levels, so you might be better suited with a smaller inverter. Because the output of solar panels will decrease slightly over their lifetime, a smaller inverter will operate more efficiently than a large one (once the panel output begins to decrease).
Chinese Vs European Solar Inverters
Due their reliability and consistent build quality, European brands are favoured amongst solar engineers. Having said that, Chinese manufactured inverters are gaining ground and many Chinese brand inverters are becoming just as reliable as their European counterparts.
Quality European Brands Include:
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SMA
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Fronious
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Delta
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ABB
Quality Chinese Brands:
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SolaX
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Grow Watt
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Eversolar
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GoodWe
- Sungrow
- Huawei
Taiwanese Brand:
- Delta
Quality North American Inverter Brands:
- Enphase (micro-inverters)
Middle Eastern Brands:
- Solaredge
