Micro invertor for PV

Barry · 05-23-14, 02:53 PM

Has anyone installed these and what are the advantages?

ecomodded · 05-23-14, 05:35 PM

With a micro controller it generally controls just one panel so you would use 10 or 20 of them in a large array.
One benefit that I am aware of (there may be others) is that if you have a failure it will only effect the 1 panel/micro controller and not the whole PV array.

(I do not think they are anymore efficient then the large units just more redundant)

I am not using a micro controller so just speaking off the top of my head..

jeff88 · 05-24-14, 02:16 AM

Micro controllers allow you flexibility in your system. If you have times of extreme shade, you can install micro inverters to allow unshaded panels to work properly. They also allow you to control and monitor a single panel by itself, extremely important for maintaining the system. You can see how each panel is producing at any one time, which might tell you what section of the system is working at any one time and can tell you if a single panel is broken or malfunctioning.

One problem with micro inverters is the added cost of the hardware. You will need one for each panel (you might be able to get away with a couple for each, but you will need to check the specs of the inverter). You also have that many more items that can potentially fail.

At my company, we sell a software based micro inverter program to provide the same benefit without the potential for hardware failure. See if you can by a similar software program.

where2 · 05-24-14, 11:04 AM

As others have already noted, increased performance in case of shading, per panel reporting, failure redundancy.

There's 20 micro inverters on my roof. I was able to run two 220V circuits to my second floor attic using 10 gauge wire with a very reasonable voltage drop, despite the length of the run.

Barry · 05-24-14, 03:05 PM

Thanks for all the comments. Now to take the next step and purchase a micro invertor and do some tests

Ryland · 05-27-14, 12:00 AM

The big advantage is that you tend to get more out of each panel because you are cutting back on your losses by stepping up to a higher voltage right away, you also tend to get maximum power point tracking from each panel instead of from the whole group of panels averaged out.
You also save money on wire by being able to use smaller gauge wire.

I forget who makes it, but someone out there makes a Maximum Power Point Tracker that mounts on the back of each panel, panels are then wired together for higher DC voltage and go to a single inverter to change it to AC.

Don't just buy one to "try" unless you are going to put it to use, design a system, install it and put it to use, it's proven, it will work, just do it.

05-23-14, 02:53 PM	#1
Barry Lurking Renovator Join Date: Sep 2012 Location: Rooiels, South Africa Posts: 2 Thanks: 1 Thanked 0 Times in 0 Posts	Micro invertor for PV Has anyone installed these and what are the advantages?

05-23-14, 05:35 PM	#2
ecomodded Supreme EcoRenovator Join Date: Sep 2012 Location: Vancouver Island,Canada. Posts: 1,037 Thanks: 116 Thanked 100 Times in 87 Posts	With a micro controller it generally controls just one panel so you would use 10 or 20 of them in a large array. One benefit that I am aware of (there may be others) is that if you have a failure it will only effect the 1 panel/micro controller and not the whole PV array. (I do not think they are anymore efficient then the large units just more redundant) I am not using a micro controller so just speaking off the top of my head.. Last edited by ecomodded; 05-23-14 at 05:38 PM..

05-24-14, 02:16 AM	#3
jeff88 Lots of questions Join Date: Aug 2013 Location: San Jose, CA Posts: 73 Thanks: 27 Thanked 2 Times in 2 Posts	Micro controllers allow you flexibility in your system. If you have times of extreme shade, you can install micro inverters to allow unshaded panels to work properly. They also allow you to control and monitor a single panel by itself, extremely important for maintaining the system. You can see how each panel is producing at any one time, which might tell you what section of the system is working at any one time and can tell you if a single panel is broken or malfunctioning. One problem with micro inverters is the added cost of the hardware. You will need one for each panel (you might be able to get away with a couple for each, but you will need to check the specs of the inverter). You also have that many more items that can potentially fail. At my company, we sell a software based micro inverter program to provide the same benefit without the potential for hardware failure. See if you can by a similar software program.

05-24-14, 11:04 AM	#4
where2 DIY Geek Join Date: Apr 2013 Location: Sunny Florida Posts: 401 Thanks: 74 Thanked 83 Times in 73 Posts	As others have already noted, increased performance in case of shading, per panel reporting, failure redundancy. There's 20 micro inverters on my roof. I was able to run two 220V circuits to my second floor attic using 10 gauge wire with a very reasonable voltage drop, despite the length of the run.

05-24-14, 03:05 PM	#5
Barry Lurking Renovator Join Date: Sep 2012 Location: Rooiels, South Africa Posts: 2 Thanks: 1 Thanked 0 Times in 0 Posts	Thanks for all the comments. Now to take the next step and purchase a micro invertor and do some tests

05-27-14, 12:00 AM	#6
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	The big advantage is that you tend to get more out of each panel because you are cutting back on your losses by stepping up to a higher voltage right away, you also tend to get maximum power point tracking from each panel instead of from the whole group of panels averaged out. You also save money on wire by being able to use smaller gauge wire. I forget who makes it, but someone out there makes a Maximum Power Point Tracker that mounts on the back of each panel, panels are then wired together for higher DC voltage and go to a single inverter to change it to AC. Don't just buy one to "try" unless you are going to put it to use, design a system, install it and put it to use, it's proven, it will work, just do it.