In our last blog of this series, we discussed why and how you should clean your solar panels if you choose to do so on your own. Now let’s discuss some other key components in your photovoltaic (PV) system and how best to maintain their optimal performance.
Photovoltaic DC String Inverters
Photovoltaic DC string inverters are the power plant of your solar array. These devices receive the direct current (DC) energy generated from your solar modules and convert it to a form of energy that your house can run on, alternating current (AC).
There are several key things to be aware of when it comes to DC string inverters. While DC string inverters are very efficient at converting DC into AC, some energy is lost in the form of heat during the conversion process. On a bright, sunny day, the inverter may feel warm to the touch. This is quite normal, and the inverter has several built-in ways of dissipating this heat because excessive heat can cause electronic components to fail.
Inverters either come with built-in fans to cool them off and/or have many metal fins that act as a heat sink to carry heat away from the inverter and into the air surrounding it. Here’s how you can help keep inverters cool so that they can operate for many years to come:
- If possible, locate inverters indoors in a regulated environment, or in the shade of your house on the north side where it will receive very little direct sunlight. Keeping inverters cool and out of the weather will help it to last and keep digital display screens on the front of your inverter from fading in harsh UV light.
- Keep the space around your inverter free from clutter and allow easy access to the inverter. This will allow more airflow around the equipment, which in turn carries excess heat away, keeping your inverter cool. This also allows you to read the screen if gathering daily solar production and provides service technicians with easy access in case there are some needed repairs to perform.
- Every now and then, it may help to dust off your inverter with a dry, clean rag. Some inverters have fans and air filters that may become clogged with dust over time. Blockages may cause fans to fail and may hinder the proper cooling of your inverter.
- Inverters can produce a humming sound during regular operation. Occasionally this humming can be quite loud, so if possible, place your inverter in a location where the humming will not cause a disturbance.
- Do check on your inverter from time to time. Most inverters display a green light of some sort when functioning correctly. Inverters will often display a red light in the case of an error, along with an error code. If you notice this, contact IPS and speak with a service technician who can help diagnose this issue.
- Inverters typically come with a ten-year warranty. While it’s easy to forget about this when your system is brand new, it’s worth checking on your inverter right before the warranty expires in case there is an issue with the inverter that is covered. These proactive checks will save you a lot of money!
SolarEdge Commercial Power Optimizer
A second option that some customers may have along with a central PV DC string inverter is power optimizers. Power optimizers are little devices connected to and located beneath each module. The theory behind power optimizers is that they optimize the performance of each panel individually. Some of the benefits of this include:
- Enhanced performance of each panel by minimizing the effect of shading on large strings of modules.
- Ability to connect large groups of modules located on different roof surfaces with different aspects and tilt angles.
- Allows inverters to operate at their most efficient by regulating the output of each module at its optimal voltage/current potential.
Optimizers are installed in conjunction with a central PV DC string inverter. Maintenance for the DC string inverter is the same as mentioned above. However, the optimizers require much less maintenance, given that they are located underneath each panel. Your inverter manufacturer has developed a monitoring platform that you will have access to, which displays data sent from each of the optimizers. It is good practice to view this data at regular intervals 2-4 times per year to determine that everything is working properly. If an optimizer is malfunctioning, the error message will show up on the monitoring website. If this occurs, please contact IPS to set up a service visit to address your issue. Other than that, there is no additional maintenance that you need to perform. How easy!
Some PV systems, rather than having a single DC string inverter, will have a microinverter on the back of each PV module. A microinverter performs the same function as a DC string inverter, converting DC to AC. In the case of microinverters, each module operates independently of the other. There are several benefits to this type of system, including:
- Increased production if there is some moderate shading on your array.
- Redundancy, in case one of the inverters breaks down – the rest of your system keeps producing power.
- Module-level rapid shutdown – a safety feature which is now required by many jurisdictions
Microinverters, like optimizers, are located on the roof underneath each panel, making it impossible to see if any are malfunctioning through visible inspection. Luckily, manufacturers have developed sophisticated monitoring platforms that relay lots of data from each microinverter to a web-interface that you, as a customer, are able to view. All you must do to make sure your system is running at its best is to keep an eye on this monitoring platform a few times a year at regular intervals. If there is an error with an individual microinverter, it will be shown on the module platform, and it will even guide you to the specific panel and its location in the array. If you notice there is an error with a microinverter, please contact IPS to set up a service visit to address your issue.
That’s all you need to know about maintaining your microinverter system! It’s as easy as watching your monitoring system a few times a year. Enjoy!
About the Author
Dustin Rothenberg is an Electrical Apprentice and Service Manager for IPS. Previously, he worked Trail Crew for Yellowstone National Park and Golden Gate National Recreation Area for six years. He has completed both New Hampshire and Montana Conservation Corps. Dustin is a board member of a dance organization called the Downbeat Vintage Swing Society, which promotes vintage swing dancing in Bozeman. He takes copious amounts of dance lessons, from Rumba, Cha Cha, Salsa, vintage Swing, etc. and dances 3-5 nights per week.