Over the next few months we will take a look at some of the more commonly used solar panels and solar inverters in Adelaide solar installations and look at the pro’s and con’s of the various brands on offer. Besides the technical merits of panels and inverters, as we have stressed elsewhere on this site, the ongoing support, back-up and claim-ability of warranty are as important when looking at which solar components to go with. Solar companies should quite rightly point out the various features and benefits of their offer, but if you are not confident that after sales support will be available then it could be wise to look at other options. The feedback we get is that if anything is going to fail in a solar panels system it is more than likely going to be the solar inverter.
Power Conversion – The Role Of The Solar Inverter
Even with the reliability of modern electronic design practices and manufacturing techniques it is important to realise that inverters fall into the area of electronics known as ‘power conversion’ – meaning that the direct current generated by the solar panels is fed into the inverter and the inverter has to convert that direct current into a sinusoidal waveform and ensure the outputted voltage and phase is compatible with grid supplied a.c. electricity. Complex stuff! Add in features like m.p.p.t. (Maximum power point tracking) and you can begin to understand the complexity of the electronics in a modern inverter. On top of this design complexity inverters have to work with kilowatts of power (dependent on the size of the system) – the enemy of electronic equipment reliability is heat – so the design of the modern day inverters has to take heat-sinking, high efficiency semiconductors and correct manufacturing techniques into account to achieve long term reliability. Given that Adelaide summers can reach 40 degrees Celsius (+) this also means that the inverters thermal design considerations are very important in ensuring 20+ years of reliability. Think about this when tossing up between a low cost inverter and a recognised ‘brand-name’ inverter with an excellent track record in the South Australian environment.
As we discussed above the reliability of your entire solar system hinges predominantly on the inverter because the likelihood of a failure of a solar system is most likely to be linked to to your inverter. Given that the function of the inverter involves complex power conversion involving ‘switch-mode’ electronics, the correct design, heat-sinking, thermal engineering and efficiency design practices are of the utmost importance if the inverter is to operate for 20+ years and transfer the maximum amount of power from your solar panels to your home and back onto the mains grid. Hence choice of which solar inverter you go with is very important.
SMA is a German based manufacturer of inverters and has more than 5000 employees. They manufacture an impressive range of inverters and accessories for many applications including:
- Sunny Boy rane of Solar Inverters For Small Systems (20 Kwatt and less)
- Windy Boy Inverter – for Wind Power Applications
- Sunny Tower Inverter Range for commercial solar up to 48 Kwatts
- Sunny Central Inverter range for solar power plants up to several Mwatts
- Inverter Monitoring Systems and Associated Software
- Off Grid Inverters
The Sunny Boy range of inverters is extensively used in Adelaide in residential solar installations and typically are designed as transformer-less, which is generally seen as producing high efficiency / low loss inverter performance or low frequency transformer based inverters, where the switching frequency is kept low to make internal filtering ( in the electronic design) relatively simple and the possibility of radio-frequency emissions generated by the unit, to a minimum.
Reputation. SMA Inverters are often seen as setting the ‘benchmark’ in Australia for performance and reliability and, very importantly after sales support – a question you should discuss in detail with any solar company offering you a quotation. Exactly what is the replacement policy for the inverter if it should break down and who does the replacement? Who is responsible for replacing a faulty inverter – the Adelaide solar installation company or the solar inverter supplier?
Given SMA were founded in 1981, it is fair to say they have certainly ‘stayed the course’ and have consistently developed new, innovative inverter products. Our view (and we have no vested interest) is that considering an SMA inverter as part of your solar system could be a wise choice.
Further reading at the the SMA website: http://www.sma-america.com/en_US/home.html