Best Solar Inverters 2019
The title for best grid-tie solar inverter has never been closer as many of the top manufacturers release advanced new models with clever online monitoring and smart home control features. The hype around home battery systems or hybrid systems is also growing, but it is early days for batteries and the majority of solar installations still require a dedicated solar inverter. Even the much anticipated Tesla Powerwall 2 with its inbuilt inverter requires an additional solar inverter to work with a solar array.
Solar Inverter function & problems
The solar inverter is the most sophisticated part of any grid-tie solar system and unfortunately it's also the part most likely to have issues. This is not surprising considering inverters are usually located outside in harsh weather conditions including rain, humidity and extreme heat, all while generating thousands of watts of power for up to 10 hours a day. This is why it's important to use a quality inverter and mount it in a sheltered location if possible.
Due to extreme variations in humidity and temperature it is likely that many inverters mounted outdoors will experience a fault at some point during their lifetime. However the life of a solar inverter can be significantly increased by locating it inside a garage, under a carport and out of direct sunlight.
A common grid-connected solar system - DC power from a string of solar panels is converted to AC power by the solar inverter which can be used either by the home appliances or fed into the electricity grid.
Solar panels can also develop problems over time which can result in poor performance, but unlike a faulty inverter this will generally not result in complete system shutdown. With this in mind it is worth while paying the additional cost for a reputable manufacturer (one which has been in good business standing for 5+ years and with extended warranties if available.)
Warranty and Service
Fronius, SMA and SolarEdge have ranked on top of the list for many years due to the low failure rates and great service as they usually ship replacement units in 3-5 business days. Fronius and SMA are available with 10 year warranties while SolarEdge offer a leading 12 year manufacturers warranty. Many of the lesser known 'value' brands will only repair a faulty unit if it is shipped to them (at the owner costs) and returned which often takes weeks and sometimes months. This will have a much greater financial impact due to system downtime.
Solar Inverter Types
String Solar Inverters
This review is focused on 'string' solar inverters which use a string of solar panels linked together in series. String inverters are the most common type of inverter used in Europe, Australia, Asia and growing in popularity in the US where micro-inverter are also very popular.
Hybrid Inverters
The new generation all-in-one hybrid inverters combine a solar and battery inverter together in one unit. These inverters are becoming much more competitive against solar inverters as batteries become cheaper and more appealing.
Off-grid Inverters
Off-grid or stand-alone power systems require powerful battery inverters with inbuilt chargers that can be setup as either AC or DC coupled systems. The modern flexible off-grid inverter/chargers, also known an multi-mode inverters, can be used to create advanced hybrid grid-connected systems.
Micro Inverters
Enphase Energy are known as the industry leading micro inverter manufacturer.
Micro Inverters are very small solar inverters attached directly to individual solar panels. Since each micro inverter and panel can operate independently they are a great option for complex roof layouts and locations with shading issues. Micro's are very popular, especially in north America and although they can be more expensive they do have several advantages over string inverters.
Inverter Rating Criteria
The following criteria was used to determine the best solar string inverters available on the market together with continuous feedback from solar installers and industry specialists. Note this comparison is focused on the common grid-tie solar 'string' inverters (single phase) although the larger commercial 3-phase inverters from the same manufacturers are equally well regarded.
- Quality & Reliability
- Service & Support
- Warranty
- Features
- Monitoring
- Price
Price Range
There is a considerable price difference between the hundreds of different solar inverters available. For example a low-end 5kW inverter can start from as low as $850, while a premium quality 5kW inverter with 10+ year warranty may cost $1800 or higher. However considering the higher failure rates of many low-end/cheap inverters and difficulty claiming warranties we recommended you invest in a higher quality unit. As a common saying in the solar industry goes 'the cheapest product will cost you more in the long run'.
Best Residential Solar Inverters 2019
1. Fronius - Primo and Galvo
2. SolarEdge - SE and HD wave
3. SMA - Sunny boy
4. Sungrow - SG-KLT
5. Solax Power - X1
Best Commercial Inverters (3 Phase)
1. Fronius - Symo and Eco
2. SMA - Sunny Tripower & Core 1
3. SolarEdge - SE 3-phase
4. Sungrow - SG-KTL range
5. ABB - Trio, PRO and PVS
Top 5 Solar Inverters - Residentia
Below we describe the top 5 residential solar inverters for 2019 based on quality, features, monitoring, warranty and service, together with feedback solar installers and industry professionals around Australia.
1. Fronius
Fronius Inverters have surged in popularity since the release of the snap-in design around 4 years ago. The high-end Austrian manufactured inverter range has definitely become the inverter of choice for many domestic and commercial solar installations. Although customers are also raving about the performance and reliability, plus the great customer service from Fronius in Australia. The high demand for these premium inverters has resulted in some supply issues at times and there have been some minor faults, but overall feedback is extremely positive and any issues have been promptly corrected. An additional free 5 year extented warranty is available when the inverter is registered online and provides a total 10 warranty period.
One of the clever features is the integrated solar DC isolator which means an external isolator box is not required, resulting in a much neater installation. Also the unique snap-in design makes servicing and installation very simple.
The Fronius 3-phase Symo and ECO inverters are also widely regarded as the best commercial inverters and have dominated the larger scale solar market due to the features and proven reliability.
System Monitoring
Wifi monitoring comes standard with all inverters via the Fronius Solar.Web. The addition of the Fronius Smart meter enables monitoring of energy generation and consumption and can be used as a complete home energy monitoring system. A free solarweb smart phone app is also available for android of iOS. There is also the option of adding the Fronius Ohmpilot which is designed to automatically use excess solar energy to heat water.2. SolarEdge
SolarEdge inverters have becoming increasingly popular in Australia and around the world over the last few years due to the unique design using DC optimisers which enable individual panel level monitoring and control - more information below.
The recently released HD wave (SE-H series) is one of the smallest and lightest inverters on the market and according to the specifications is also the most efficient at 99% for the larger 5 - 6KW models. This new generation inverter uses advanced thin-film capacitors and digital processors to produce a clean AC output with very low losses. All Solaredge inverters must be installed in combination with the DC optimisers (see below) which perform part of the job of a common string inverter so this is perhaps the reason Solaredge was able to package such a small efficient inverter.
The biggest advantage SolarEdge has over the competition is panel level monitoring and power optimisation through the use of panel mounted DC optimisers.
DC Optimisers are small electronic modules attached to the back of the solar panels which allow for individual panel level monitoring and power optimisation. Previously individual panel monitoring was only obtained through the use of micro-inverters, plus some add-on optimisers such those from Tigo Energy. The unique Solaredge Optimisers enable longer strings of panels (up to 22 modules) and increased safety in addition to reducing the detrimental effects of shading and panel faults, plus provide early detection of potential issues. However they can add to the complexity of the system and being an electronic device mounted on the roof may have the potential to cause issues in the longer term.
Panel shading a problem? For complex roof profiles or installations with shading issues this would be the inverter of choice.
SolarEdge also has an industry leading 12 year warranty period.
System Monitoring
SolarEdge inverters have 'optional' wifi which together with the optimisers can provide power output data for each panel individually. This is great for both system monitoring and a very good tool for fault detection, especially for installers. Also SolarEdge definitely have one of the best smart phone apps for remote system monitoring.3. SMA
German manufacturer SMA Solar Technologies had been regarded as the best string inverter manufacture on the market before the snap-in series from Fronius took the top spot in 2016. SMA’s decision to locate manufacturing of the new AV series in China rather than Germany also hurt the companies sales and reputation, however SMA have now chosen to relocate all manufacturing back to Germany in 2019. The larger 3-phase commercial inverters from SMA which have always been manufactured in Germany are still widely regarded as one the best inverters on the market.
SMA inverters have a proven track record for reliability and are generally considered one of the highest quality inverters available. Local service and support is very reliable and SMA provides an optional extended 10 year warranty.
Unlike the well regarded Sunny boy TL inverters the latest AV inverter series from SMA does not have a display panel and relies solely on wifi communication for setup and monitoring. Display-less inverters are becoming an industry trend as many other manufacturers are releasing new models without a display. A digital display in an outdoor environment can be problematic so this may reduce faults and warranty issues in the long term, but only if the communications is very reliable and stable. Without a wifi signal and no display can make things difficult to troubleshoot if a problem does occur.
System Monitoring
SMA have one of the best free monitoring software packages available known as the Sunny portal. Since the new Sunny boy inverters have no display for setup and monitoring, reliable communications will be vital to the success of the new models. Most SMA inverters have the wifi webconnect capability as standard and with the additional Sunny home manager 2.0 (energy meter) although rather expensive is required to create a complete home energy monitoring system.
SMA have one of the best free monitoring software packages available known as the Sunny portal. Since the new Sunny boy inverters have no display for setup and monitoring, reliable communications will be vital to the success of the new models. Most SMA inverters have the wifi webconnect capability as standard and with the additional Sunny home manager 2.0 (energy meter) although rather expensive is required to create a complete home energy monitoring system.
4. Sungrow
Founded back in 1997 by a university professor Sungrow is one of the largest suppliers of solar inverters globally and a leading Chinese inverter manufacturer. The residential SG-KTL Sungrow inverters have become very popular among Australian installers due to the competitive price and great reliability record, plus Sungrow is a very large player internationally and has a good reputation for service and quality compared to most Chinese inverter manufacturers. Sungrow offer very good support from the Sydney based office in Australia which has further helped improve their reputation.
In addition to the well regarded range of solar inverters Sungrow also manufacture one of the best value hybrid solar inverters on the market - the new generation SHK5-20 inverter is a very affordable hybrid inverter for home energy storage systems and comes with an optional back-up device for protection during a blackout.
The new generation Crystal G2 and SH5K-20 solar and hybrid inverters recently released have had great feedback, are very good value for money, plus look much more modern than the previous models.
System Monitoring
Sungrow inverters include Wifi monitoring as standard on all residential models and use the online new modern monitoring portal ISolarCloud which is a huge improvment. The free smart phone App is also very simple and works well.
5. Solax Power
Solax Power is a relatively new inverter manufacturer which was largely unkown in the industry until they launched the economical battery X-hybrid inverter. Solax is a subsiduary of the the much larger Suntellite Group in China which manufactures solar cells, panels and inverters with a strong emphasis on research and development. This is possibly why they have been able to produce high quality inverters with advanced features compared to many other Chinese manufacturers. Solax Power also has a strong global presence with an Australian support office located in Melbourne. The current X1 range of solar inverters do not have the sleek designs of the european rivals but at close to half the price you wouldn't expect them to compete on this level, their slogan sums them up nicely 'simple, reliable, efficient'.
One of the clever inverter options from SolaX is the very affordable X-hybrid unit which is one of the most economical battery ready solar inverters available. Due to the low pricing the new range of Solax power inverters soon to be released may put some pricing pressure on the premium inverters brands above.
Solax is also one of the few inverter manufacturers to produce large 3-phase hybrid battery inverters for larger residential and commercial applications.
System Monitoring
The Solax online monitoring portal V2 is quite impressive and offers access via smart phone apps or web interface with battery management features for hybrid systems and email reporting, although the wifi dongle is an optional extra.