Question

How long do solar panels last?

Asked by Ed Vedder
Saint Louis, MO

I am buying a home that already has panels on the roof that were installed 5 years ago. I understand the best thing is to have someone inspect them but is there a general lifespan?

Answer

Ed,

Typical manufacturer's warranty for a photovoltaic panel is 25 years, and as long as they are cleaned regularly, protected form violent acts of nature they should continue to function long after.

  • The nice thing about photovoltaic panels is that there are no moving parts to wear out over a long period of being in service.
  • Most defects or interruptions in service occur at the connection points, within the electronics of the inverters and manual contactors which have had moisture infiltration causing corrosion.

Ask a licensed electician to inspect the solar panels

It is a great idea to have the photovoltaic panels inspected to ensure that they were installed and functioning properly.

I would recommend that the individual inspecting the panels and their connections is a licensed electrician.

Contact the panel manufacturer to receive a list of representative in your area. They should be able to supply you with a list of green electricians best suited to inspect and test your system.

Here are few areas they should be looking at:

  • All connections between each panel
  • Wiring within the combiner boxes.
  • DC disconnects
  • Inverters operating software
  • Gross DC production and Net AC production to verify that it is within the limits of the inverter manufacturers specifications
  • Connections to roof or structure
  • Damage to glass plate of each of the panels caused by acts of nature

Maintenance

Follow all manufacturers’ recommendations for routine maintenance.

Following these simple steps in maintaining your photovoltaic panels will result in many years of uninterrupted service. 

Tips for routine maintenance:

  • Wash panels regularly
  • Cycle disconnect switch to ensure that corrosion will not build up
  • Verify or receive manufacture software updates for the inverters
  • Inspect water tightness of combiner boxes if located outside
  • Inspect points of connection to the roof and or structure to ensure water tightness

 

For more information:

Read Anthony Addesso's Q&A "I want to convert to solar energy. Where do I start?" and Christine and Robert Boles's Q&A "How much will it cost to install solar panels on my 2,000-sq.-ft. home in San Francisco?"

Also, read Paul Rosen's Q&A "Can you tell me how well solar hot-water heaters work?"

Tagged In: solar panels, durability

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