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How do I know if my solar panels are working correctly?

Posted by Tasha Kosviner on 24 April 2015 at 4:10 pm

1. Keep an eye on your generation meter  
Check your generation meter once a week and keep a record of the figure. Your meter should clock up energy generation every day, even in dull weather. Keeping a regular eye on it will help you notice any variation over time that doesn’t seem to be related to changes in weather. The generation meter will also probably have a red LED light which will be permanently lit when the system is not working. If this is lit during the day you can be sure the system has shut down.

2. Consider a monitor or web-based monitoring
Most monitors will store data for downloading so you don’t need to do manual checks. They may also indicate when any faults are present. Even easier is a web-based monitoring system which records generation data for you and can alert you to any notable variations.

3. Check your generation against your installer’s quote
Your installer will have estimated what your system should be expected to generate and this will be detailed on your quote. If you used a reputable installer, this calculation would have been done using a SAP methodology as prescribed by the Microgeneration Certification Scheme (MCS) standards. The quote should also give you expected monthly variations which are dependent on predicted sunlight hours at different times of the year. Whilst the estimate cannot accommodate for an unexpected run of stormy days in August, your system should have been carefully designed so that your actual output more or less matches or even exceeds, the projections on your quote.

4. Clean your solar panels
Solar panels generally require very little maintenance and the fact that they are usually installed at an angle means that they are kept generally clean by rainwater. However, a build-up of dust or bird droppings will affect their performance over time. If you feel there’s been a change following a very dry spell of weather, or if you live by a busy road, or even in salty air by the sea, you could consider getting up on the roof and gently cleaning them with water. Do not use a high pressure hose. There are companies which offer a cleaning service and others who apply a protective coating to panels. You may wish to try going down that route if you suspect an unseasonal dip in performance.

5. Talk to your installer
The very best installers are enthusiasts and solar geeks who are interested hearing about how their installations are performing. Once your installation is complete, be sure they give you a really good run down of how the system works and how to check performance. A really good local outfit should send someone out to check if you suspect your system is not performing as anticipated.

Photo: SuperHomes

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4 comments - read them below or add one


paul53Comment left on: 20 September 2015 at 8:01 am

as  long  at  the  connection is  after  the  meter it  should  not be able to  add to your  reading

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Ian Dickson

Ian DicksonComment left on: 16 September 2015 at 5:23 pm

Hi, I read a daily telegraph article saying some installations were incorrect and we're adding the solar produced to your reading. Could it be this?

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HazrockComment left on: 8 May 2015 at 12:49 am

Check the actual generation meter, not the small indoor one with the pretty lights as that doesn't tell you if the main solar meter has stopped working!

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HeidiPComment left on: 1 May 2015 at 1:17 pm

Thank you, that is really useful - I am rather confused and keeping a tally as my electrical usage appears to have increased since having the panels installed last year so something of a mystery!


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