What’s the Different Types of Solar Pv Systems And Solar Inverters? Part 1: Your Options
Solar power system in Adelaide have evolved over their many years of existence. Over the past 15 years the industry has seen a solid push forward in new solar power technologies both in the solar panel manufacturing industry, the solar inverter manufacturing industry and now we have additional power controls and highly advanced energy monitoring capabilities that are commercially available that are cost effective.
When making any kind of purchase you wouldn’t compare apples with oranges would you? Well believe it or not that is exactly what most people unknowingly do when deciding on a solar energy solution. I know solar is a confusing market and it doesn’t help that every single darn sales guy promises you that only their product is the best on the market. You will normally hear that followed by “We have a super limited time only bonus special just for you, buy 18 panels right now and I’ll give you 4 free!” normally followed by “This deal is only available if you sign up right now” spoken in a thick foreign accent. Normally the low price, flash in home, boss approved sales looks great on the surface but very rarely will your experience with companies like this be a long and prosperous one. Like the old sayings go, nothing good is cheap and Nothing Cheap is Good. You get what you pay for. These types of high pressure sale tactics have really tainted my beloved clean green energy industry. So today I wanted to clearly explain the differences behind each system so that you can easily understand the difference between an apple, an orange and a black diamond encrusted, 24kt white gold, platinum accented solar inverter.
The most common comment we hear from a client when we provide them with an Adelaide solar panel quote is “I’ve been told by my friends the German inverters are the best I only want that please”. To be fair, years ago a German solar inverter like the SMA Sunny Boy was the only way to go to ensure a long lasting quality solution was provided because their was so much cheap unregulated junk in the solar market that couldn’t be trusted. The truth is that the industry has evolved and has cleaned up dramatically to the point where even SMA now makes their beloved Sunny Boy solar inverter range at a facility in China. Most of the cheaper Chinese products that remain in the market are those who have been around for years and provide local after sales support and have enhanced the quality of their product over years of research and development so there’s more reliability in the cheaper options nowadays that there use to be but you still need to be cautious. I could go on for days about this topic but I have decided to keep it as short as possible and I will break up this blog into 2 parts. Part 1 is the break-down of different inverter topologies. In Part 2 we will discuss different analogies to differentiate different branded inverters and where we feel they sit in the market place.
Here we go….. Part 1 – Inverter Topologies:
So there are many different brands of solar inverters but what are the different types of solar inverter topologies in the market now? You have your standard/traditional DC string inverter (the likes of SMA, Fronius, ABB, Zeversolar, GoodWe, Sungrow etc). Then you have your DC optimizer systems (Solaredge, Tigo). Then you have your Micro inverters (Enphase).
What’s What?
A standard DC String inverter is where a number of solar panels are wired together and then the collective DC power output of the solar panels gets converted into AC energy through the DC string inverter. This is the oldest style of solar inverter, the simplest in design, and is the most cost-effective solution if you are price driven and don’t care for any bells and whistles or advanced monitoring. This solution is not recommended if you have any risk of potential shading as with a standard DC string inverter the weakest performing panel will bring the performance down of all the other solar modules it is wired together with. DC String inverters have very limited installation flexibility and is normally an ideal solution for large roof area of one or two orientations only. The Globally renowned most reliable products in this range are the European made SMA & Fronius inverters followed by the Chinese made ZeverSolar inverter which is owned by The SMA Group.
The next topology is a DC Optimised system which is basically a middle ground hybrid between a DC string system and a Micro Inverter System but shares more similar characteristics to a micro inverter minus the panel level current conversion. A DC Optimiser is small device that is mounted behind each individual solar panel that effectively works as a brain for each panel allowing them to function independently and harmoniously with the other panels it is connected to. The DC string inverter that the panels are connected to communicates with the DC optimiser to regulate the current when a panel is not performing as it should and the other panels effectively are told to pick up the slack. This leads to greater efficiency, longer inverter life and proactive maintenance. As the current is being regulated by the inverter, SolarEdge have a unique safety feature that if there’s ever a fault or risk of danger in the system, the inverter will go into rapid shuts down mode all cabling voltage will be reduced to an extra low safe voltage. Other key benefits is greater flexibility with design and installation layout making it an ideal solution for shaded roof areas, premises with limited roof area and designer properties that have multiple roof orientations .A DC Optimiser Inverter solution is ideal for sites with shading issues, different roof orientations, where customers want to know exactly what is happening with every part of their solar system and is our recommended solution for any residential and commercial solar solution. The industry leading manufacturer of DC Optimers is SolarEdge. A SolarEdge system is a highly flexible inverter solution that is easily battery ready with a simple add on device called the StorEdge retrofit battery charge or you can get a hybrid battery ready StorEdge all in one inverter.
A Micro inverter is a small DC-AC inverter that is mounted behind each individual solar panel which converts the DC output of the solar panels to AC output immediately on the roof. This solution is extremely flexible being able to function with as little as only 1 panel and can be installed on many different orientations. As the current is converted at the panel it doesn’t require any high voltage roof top DC isolators and if there’s ever a fault in the system, the AC circuit breaker will trip and shuts down all cabling voltage to an extra low safe voltage. Every panel functions independently so this solution is best suited to sites with shading issues, different roof orientations, smaller sized installations. The leading brand of micro inverter available on the market is the Enphase micro inverter who are just releasing their 7th generation of micro inverter June 2018.
To be continued……
