Save yourself the heartache of making a bad inverter decision. The SMA Sunny Boy AV-40 is the modern version of the world famous SMA Sunny Boy TL. An inverter once considered the pinnacle of single-phase solar inverter technology. Therefore, the question must be asked, how does the new SMA Sunny Boy AV-40 compare, not just to its predecessor, but also to modern rivals? 

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Make and model:  SMA Sunny Boy AV-40.

Variants: 3.0 | 4.0 | 5.0.

Good: Warranty, Software, Features. 

Not so good: Service warranty.

Embroiled in controversy the new SMA Sunny Boy AV-40 certainly has had its share of criticism. Die-hard SMA advocates suggest that shifting manufacturing locations from Germany to China would be the great undoing of a respected inverter manufacturing powerhouse (see update below). Others would suggest that removing the graphic display isn’t what consumers wanted. The SMA Sunny Boy AV-40 indeed was the boldest move the solar industry had seen by a manufacturer in a long time. 

Comparing the essential criteria of design, features, performance, software, guarantee and affordability may finally settle the debate once and for all.

Update: Sunny Boy AV-40 production shifts back to Germany in 2019 >

Which SMA inverter do you require? The SMA Sunny Boy AV-40 is the modern single-phase inverter by SMA for systems rated at 3kW or above.

  • Single-phase, 1.5 – 2.5kW, SMA Sunny Boy VL-40 >
  • Single-phase, 3 – 5kW, SMA Sunny Boy AV-40. (You are here)
  • Three-phase, 3 – 6kW, SMA Sunny Tripower >
How to know if you have a single phase or 3-phase power supply? >


SMA Sunny Boy AV-40 LED Interface - Solar Review

The most controversial element of the new release SMA Sunny Boy AV-40 is without a doubt the modern design. Although what appears to be initially distasteful should be viewed as a healthy progressive evolution or quite simply, an inspiring design.

As home appliances evolve to be more communicative and reliable, so must solar inverter technologies. No longer just a means to convert DC to AC energy, a common point of failure in all solar inverters is the old black and white LCD type graphic display. The engineers at SMA have had some foresight on the reliability front and replaced the need for a graphic display with a set of multifunctional LEDs and your smart device. As we now watch TV through our smartphones, it’s not too difficult to view energy production through the same device, time to adapt.

Rounding off the SMA AV-40 design battery connectivity is available through a compatible AC or DC coupled battery technology or through SMA’s extensive range of battery inverters. The IP 65 weather rating provides versatility in mounting locations. While fan-less cooling ensures low noise and reduced serviceability over the operational life.

Download the SMA Sunny Boy AV-40 datasheet here:

4.0A SUPERIOR design, the Sunny Boy AV-40 solar inverter accrued a Solar Review Inverter Assessment Criteria Design score of 4.0 out of 5.


SMA Sunny Boy AV-40 Connection - Solar Review

Only two blemishes exist in an otherwise outstanding feature rating. Internet connectivity lacks that of a manufacturer supported 4G mobile network connection, supplying only WiFi and ethernet connectivity. Additionally, shadow management lacks mandatory module-level optimisation although SMA’s OptiTrac Global Peak shadow management protocol is a cut above most string inverter shadow management technologies. Both of which are high-end expectations and the absence ensures a lower purchase price for the technology which is viewed as a win.

As a dual tracking inverter technology, the SMA Sunny Boy AV-40 is equipped with an inbuilt DC isolator and further enhanced by the new age multi-function LED local interface. For added versatility, manufacturer supplied add-ons in module-level optimisation and rapid shutdown are facilitated through SMA’s own Tigo Energy solutions. Expanded monitoring capabilities are outstanding within the SMA range, with the widest selection of energy management and environmental monitoring systems available. Finally, the new expectation in inverter features, advanced operational parameters can be adjusted remotely to aid better system performance and improve system uptime.

4.8An OUTSTANDING feature rating, the SMA SUNNY BOY AV-40 solar inverter accrued a Solar Review Inverter Assessment Criteria Features score of 4.8 out of 5. 


SMA Sunny Boy AV-40 Top View - Solar Review

European weighted efficiency within the SMA Sunny Boy AV-40 remains within the highest calibre at 97% (avg). A wide operating temperature range facilitates diverse climates ranging between -25oC to +60oC (-13oF to +140oF), and 100% humidity.  Further complimenting the temperature range is an exceptional derating temperature point at over 50oC (at 600VDC).

A level of noise emission is present, however, unnoticeable to most. If sensitivity to acute noise emission exists, the 25dB(A) noise rating should be factored into the selection process. A significant difference from the previous model is the weight reduction by a staggering 10 kg (22 lb). The New SMA Sunny Boy AV-40 weighs in at only 16 kg (35.3 lb). A weight which is more accommodating for load-sensitive performance requirements.

Average Inverter 95%
SMA Sunny Boy AV-40 (new) 97%

Above: Solar inverter maximum efficiency.

4.1Considered SUPERIOR, the SMA Sunny Boy AV-40 solar inverter accrued a Solar Review Inverter Assessment Criteria Performance score of 4.1 out of 5.


SMA Sunny Boy AV-40 DC Isolator - Solar Review

One of the most assuring product warranties available, the SMA Sunny Boy AV-40 range comes with a resounding 10-year product warranty if purchased through the authorised SMA dealer network. A very big upside as the SMA dealer network undergoes consistent training into SMA best practice installation techniques. Assurance to the point that if the inverter is installed to manufacturer specifications the warranty will always be upheld. Selecting an SMA authorised dealer adds expedited product repair in the event of a failure and more. The only downside is that the 10-year warranty is not a full 10-year parts and service warranty. The final 5-years is a parts only offering by SMA.

Average Inverter (base)
SMA Sunny Boy AV-40 (base)

Above: Base manufacturer warranty on a scale of 12-years. 

4.2SUPERIOR, SMA Sunny Boy AV-40 solar inverters accrued a Solar Review Inverter Assessment Criteria Guarantee score of 4.2 out of 5.


SMA Sunny Portal

As of 2019 SMA Sunny Portal Users will be converted over to SMA’s next-level ennexOS monitoring platform for a superior system monitoring experience.

See the full SMA Sunny Portal monitoring software review for more insight > (Coming Soon).

Technology Ranking.

4.3The SMA Sunny Boy AV-40 range is considered an advanced product technology wise ranking EXCEPTIONAL in the Solar Review Inverter Assessment Criteria without affordability points applied. To view the overall product score and entire product summary at the bottom of this post, Keep scrolling!


SMA Sunny Boy AV-40 Logo - Solar Review

The SMA Sunny Boy AV-40 is not the cheapest inverter you’ll find, but it’s also not the most expensive either. A good compromise for a product which is subject to a renowned German quality standard.

As a gauge, SMA Sunny Boy AV-40 5 kW inverters are available online from:

 USD 1250  |  AUD 1700  |  EURO 1050 

Excludes taxes, shipping and installation.

Source – Google

4.2Presenting SUPERIOR affordability for the technology, the SMA Sunny Boy AV-40 solar inverter accrued a Solar Review Inverter Assessment Criteria Affordability score of 4.2 out of 5.


4.2Relocating production back to Germany as of 2019, the SMA Sunny Boy AV-40 range could have been much more given where solar technology is heading. Very future ready, the SMA ways of adding additional device after device to accommodate the future can prove costly depending on one’s requirements. Nonetheless the SMA Sunny Boy AV-40 is an excellent solar inverter option by a trusted inverter manufacturer.

Have a question?

OR maybe a different perspective? Have your say in the comments below.


How was the score for the SMA Sunny Boy AV-40 calculated? By utilising the Solar Review Inverter Assessment Criteria V2.0 >


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