Friday, September 30, 2016

How To Tell If You Have a Failed Microinverter On Your PV System

So you suspect that you might have a microinverter or 2 that is not reporting?

This is a simple way to "fact check" it.

Select the screen as shown below "Energy: Past 7 days" That is the key!

And speaking of "Pteradactyl Poo" what should you do if your panels are dirty?    First off DO NOT pressure wash them.   We recommend a thorough cleaning and inspection every 2 or 3 years, there is no need to get carried away with too much cleaning.    But if you live in an area where construction is going on, or people are spray painting their houses...dirt or overspray is going to build up.

We offer a "Solar PV Tuneup" the cost is based mainly on how many panels you have.   A description of the service is HERE

So you suspect that you might have a microinverter or 2 that is not reporting?

This is a simple way to "fact check" it.

Select the screen as shown above

"Energy: Past 7 days"

If all of the inverters report about the same energy, then you are good to go.   Keep in mind that for a different angle of roof, they will have different energy production, but all on the same slope of roof should be about the same.   

If one is completely black (no energy production), then it is quite likely that the inverter is dead.    But they also get partial failures as they are in the process of failing, those show some energy being produced, just not as much.

Also, if you have one of two showing less energy, take a step back and look at the roof.   Do you have a tree that grew up and is blocking?    Maybe a leaf or debris blocking a panel, maybe a Pteradactyl poo?   

A small blockage on a panel can result in not just a large loss of energy production, but instead of energy out, you get heat into the panel and that can cause a quick death of the panel itself.------------------------------------------------
What causes inverters to not report data consistently?    Simple answer but not always a simple solution.

The answer is that noise and distance on the power line (the 120 Volt AC and 240 Volt AC circuits) can prevent the microinverter from talking to the EMU/Envoy.     They communicate over the power line.   

You can check the quality of the communication by first going to devices, above.   And then clicking into the "Envoy"

It's hard to see here [see images above], but there are 5 bars available.    This system only has one bar, so the microinverters can't "talk" that well.   

The noise varies throughout the day, as appliances, motors, battery chargers, laptops are turned on and off.    So sometimes the communication is good enough, and the microinverters "dump" all their saved up information to the EMU/Envoy.

If you have any less than 3 bars of communication, Enphase (the manufacturer of the microinverter) will not entertain issuing an RMA and thus a warranty claim.     They used to be more flexible, but they are getting tougher.    

How does one improve the communications?   As one of my college professors loved to say....."That is beyond the scope of this course".    But see link in the text below.

Friday, March 4, 2016

How to Tell If My Solar Hot Water System Is Working Correctly

This is some simple troubleshooting that the system owner can do.

Of course, things can become more complex and that is when you call in the experts, but don't be intimidated by your system.

There is a very simple way to see if things are working properly:

Observe the system pump, on a sunny day, when you know you have water in the tank that is not fully up to 120F.

The system should “cycle” on and off, maybe 2 to 10 minutes per cycle.   If it is cycling then the sensor, controller, pump, panels, valves are all working correctly.

You can hear the pump slightly when its running, or you can put your hand on it and feel the vibration, but watch out, it can be extremely hot.   If you have the STECA controller, with the digital display you can also see the pump movement indicated, however, this does not prove that the pump itself is working.

If the pump is "cycling" then all is good.

If the pump  is not cycling or cycling on really long intervals, or really short intervals, then there is something wrong.

A common problem can be what we call a “vapor lock” in which an air bubble that was stuck in the tank or delivered via city water goes up to panels and blocks the movement of water, the pump cannot overcome the stuck bubble.   

This would pretty much make your solar work not at all.    And there is a simple fix for this….it is exactly what every owner should be doing at least once a year, and some recommend twice a year….the fix is called "the annual tank and panel flush"  

This not only is a required maintenance that is easy enough to do, it will also remove the air from the panels.    You will likely hear air spurting out of the hose when you  do this (I mean if there was air in the panels).     If you hear that air spurting out, then you can feel pretty good, that you have really solved the problem.