Maxim Integrated Jinko Modules
This week technical expert Ben Vinyard is taking a look at the benefits of the new Maxim integrated modules.
A very long time ago, engineers had the smart idea to use diodes in solar modules to circumvent things like cell hotspots and partial shading. For years this has remained the way it’s done. Although adding diodes to a solar module does a lot to increase a systems yield, it still isn’t a cure for shading. What if there was a better way? What if we think we’ve found what may be the future of module production? Today’s article is a technical look at the new Jinko-Maxim integrated module.
Features of a standard diode fitted module
With a few exceptions, most panels you can buy today have three diodes being used to bypass a set of cells. When the panel is in good light and working normally, the current doesn’t flow through the diodes at all. This is because a diode has a certain degree of resistance and an electrical charge will always follow the line of least resistance. But, if a sections resistance goes up (shading, hotspot, cell failure) then the line of least resistance is via the diode, which means the circuit completely bypasses that cell set.
Certainly, this is better than not having diodes there. If the diodes were not there the whole PV string would be off. But, the reality is, it still isn’t a cure for DC circuit issues. Ultimately, the system is still working, but working quite poorly.
Adding Optimisation
Module level optimisation has been a huge leap in solving DC problems. There is only one name that springs to mind when I think about module level optimisation, and that’s SolarEdge. What SolarEdge did was truly incredible. Not only did it solve the niggles of using a diode, but made system design simpler. With an optimiser, you don’t even need to worry about orientation splits anymore. Unlike using a diodes alone, fitting optimisers between each module keeps the DC circuit from panel to panel completely separated. Once you do that, the physics on the DC side become a bit of an engineer’s playground. Anything bad going on within a single module can’t affect others in the system and you can introduce power tools like module level monitoring. It’s a beautiful piece of R&D.
Maxim Integrated – who are they?
Another new name in the PV sector. So, are they a new company? Where do they come from? Well, in the world of technology, I would consider them to be a very old company, established in 1983 in California. For most of the over three decades they’ve been around for they’ve been producing internal circuits for the automotive trade, comms and IT. Today with some 8,800 employees, they are a powerhouse of a company worth around $4 Billion. Certainly in this industry, facts like that give me a lot of confidence. This year, Maxim have moved into internal circuits for PV modules and their idea is optimisation, but on a cell group level. In simple terms, they’re putting optimisers where diodes used to go.
Do I need a special inverter?
No. These optimisers are not a fixed voltage system. From a design point of view, you just treat it as a normal panel. You’ll probably come across a little bit of marketing from Jinko/Maxim that states “it’s a better panel”. I couldn’t think of a better way to word this. I honestly believe that what they have done is so good, that this is just going to be the way that all panels are made in the years to come. In the same way that when diodes were first used, everyone did the same. This is simply the natural progress engineers have made in module production. The product offers the best DC issue solve available, complete flexibility with system design and may even negate the need for multiple tracking inverters. If I’m right about that last part, less trackers will mean lower inverter prices and that’s always a good thing. The potential of what this panel could do is probably the most exciting thing I’ve seen in the last three years in this industry.
What about monitoring?
There isn’t a module level monitoring from Maxim and they won’t be developing it. They’re simply trying to make a better panel. If you want panel level monitoring, then SolarEdge or Micro’s are still what you need. In terms of what these new panels do, they simply aren’t a replacement for SolarEdge. The monitoring is usually a very important part of what the system owner wants. Believe me, my inverter of choice for my own home is still SolarEdge. The safe DC shutdown on SolarEdge is also something a maxim does not offer. There is no reason why you wouldn’t use a maxim panel on a SolarEdge system, in fact. Admittedly the SolarEdge optimiser would not increase the yield. The Maxim integrated is already doing that bit, but, the point is, Maxim integrated costs the same as a standard module. Having that technology with a SolarEdge is not a bad idea at all because the system is the same price with or without a Maxim panel, which is just “a better panel”.
Summary
Only time will tell if I’m correct, but I believe that the Maxim integrated module is a view into the not too distant future and that maybe one day we’ll all look back at diode modules and giggle a bit. The price of the module means that you don’t need consider it as a premium solution and that it’s just a better method of making a module. For now the one thing we do know is that this a huge advancement in panel production and the yield figures are speaking for themselves. Jinko have real systems and data available from all over the world. This data is publicly available and please ask if you would like to see those results. One simple final thing to say. Make the next system a Maxim integrated one…….you’d be bonkers not to.