How to properly test solar panels... Solar panel efficiency | Does it really give more energy???
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- Опубликовано: 8 июн 2024
- How do you know your solar system is working to peak performance? We go to all the trouble and expense of getting solar PV onto the roof it makes a lot of sense to ensure its working correctly.
Inverters can give us huge levels of data but they dont have the data from up on the roof to really know if whats getting sent down in lovely DC energy is working as expected.
Which is why ensuring your installer has carried out both safety and efficiency testing is so important. That way the output can be verified against real world data from the roof itself. To include temperature, irradiance and pitch.
As installers we want to ensure everything is installed to the best possible standards and performing to its maximum capability. Having equipment like the PV check, Iso test and solar 02 from @testinstrumentsolutions is so important for us.
For total clarity the wonderful team at TIS support Apprentice 121 but all the equipment shown is bought and used every week on solar jobs by everyday normal electricians in real world applications.
We are immensely grateful for all the help Steve, Mark and the entire TIS team have shown since we first ventured into solar PV. The customer support is way above others and range across both AC and DC unmatched.
I hope the solar series this weekend and today is useful! Next up we have an entire install including roof work, inverters, batteries and a wind turbine! All done in winter on a North Yorkshire cliff top location!
You can not get more real world feedback than that lol. Should be out the end of next week!
www.testinstrumentsolutions.c...
Quality and informative as always 👏
Have you tested or used an seaward pv150
Yes
@@electrician247 what's the comparison in your view
Efficiency testing, it's a bit of a gimmick. It isn't required.
The efficiency, as we know, is a function of the design and manufacture of the panel.
The panels will be tested by the manufacturer before being ahipped to suppliers. The panels will work correctly.
Let's look at the different potential use cases:
1. Initial Verification
Here you are checking that the system you installed works.
You might want a base line figure of performance of the system which you can present to the customer to demonstrate it has been properly installed.
This can be easily achieved by using an irradiance meter, messuring and recording the brightness of the sun and measuring and recording the power generated from the full set of panels.
If there isn't much sun then you will need to go back on a day where there is sun and meadure the power output again. That is how you prove the panels and the installation is working properly.
A few calculations or a piece of computer software will give you an indication of what power output you should be getting from a certain irradiance level. If you get a power output way below the expected level then you start fault finding.
2. Yearly efficiency check
Tne idea suggested in the video of doing an annual check to keep the panels working at their optimum:
Firstly the efficiency of the panels isn't going to change much. Figures for modern panels are that they still generate 80% of their original rated power after 20 years. That's a change in efficiency from say, from an initial 23% down to 18.4. That's a reduction year on year (assuming a linear relationship) of 0.23%. And if you detect the change you aren't going to do anything about it.
And the idea of calling out an electrician and his/her charging, £100 or £200 to tell you the panels are dirty or are covered in leaves, that's pretty crazy, and then the home owner pays out for someone to clean them.
And those panels could be covered in fine dust from the Sahara and could have been covered in it for 8 months before you called out the electrician to perform the annual efficiency check.
What would be far better is some permanent in-place monitoring equipment comprising an irradiance meter sending mesurement data to a control unit which also measures the power from the panels and records historical power data along with the irridiance data and process it, present it on a display and generate alarms, norifications visible to the home owner and prompt them to visually inspect the panels from ground level and make a decision to call out someone to clean them.
3. End of Life of panels.
An efficiency check would be useful to aid in determining when the panels are reaching the end of their life. But as previously indicated, decent panels are still producing 80% of their rated power after 20 years, so a yearly efficiency check is an unnecessary cost. A check at 5 year intervals would be better, or just a check at 10 years after installation, followed by at 5 year intervals.
Thats a bold statement around panels, are you an installer? We have had quite a few not outputting correctly discovered during IV of solar systems. So that statement is blatantly misleading and false. Yes the ones that are working will output to the set criteria but thats why we check. Sensible huh.
1. You are checking the system works, is safe and performing to the stated output on the panels datasheet. While that can be achieved when close to standard test conditions are present it is very hard to get a true and quick appreciation of that when it is not. More factors play a part than irrediance, temp is a big one which many over look. Without ensuring you have carried out initial verification correctly how do you know the system is set to work as sold? Risky approach imho when a client comes back with a poorly generating system due to a wiring issue or product malfunction missed during initial installation. Not a liability I would want to follow around my business installs. For a DIY approach I dont fall out with some rough cals, but as a profesional service? No not for me. Plus go back another day when there is sun??? In the UK that might not be for weeks sometimes this is much more cost effective and as discussed gives assurance.
2. Again you are missing the point here massively. We are not looking for small degredation sustained by the panels over the passing of time. We are looking for variances and subtle changes that can indicate a panel failure. Things that are perhaps not readily obvious. Perhaps a panel has sustained damage and is not outputting correctly, suffered a malfunction, connector failure or many other things. Those are not obvious without a level of interogation especially if the system was installed poorly at the outset with basic guesses based up irrediance measurements. Of course regular cleaning and checks of panels weekly or monthly by system owners are imperative but for a real overview of system performance efficiency and professional inspection brings upside in both safety and RTI. The lack of value in maintenance is not an approach I would support. System owners have rooftop irrediance meters and monitoring equipment. They are called solar panels and inverters. The trouble is many do not understand the data never mind monitor it. We should be encouraging people to get the maximum RTI through appropriate maintenance which also has the huge upside of safety....
3. I dont fall out with longer term periods between tests IF and initial efficiency test was carried out and the client has good records of generation in the inverter apps. The guidance from industry is for a form of annual maintenance which I think is very sensible based upon the results of a poorly performing system and potential for catastrophic consequences in the worst circumstance.
As professional installers it is all about evidencing we have done EVERYTHING possible to ensure that. Its called assurance for us and clients.
@@electrician247 It is not misleading. It may be incorrect.
@@electrician247 So you do an efficiency test on every individual panel before you install it? Of course not..why? Because it is a slow process.
You need to separate the efficiency of the panel from 1) Performance and correct operation of the panel, 2) performance of the complete installation.
You can achieve both 1 and 2 without measuring the efficiency of the panel.
@@deang5622 you are missing the point totally. We are testing the efficiency of the array as a whole. Which when using this tester has all the stored data from the panels inputted. That way we can see precisely if the array is performing as it should based up irrediance, temps, tolerances, coefficients and more.
We test each panel before taking them onto jobs in basic terms such as VOC. However we can not verify the performance until they are in situ as an array at the installation address.
We have found issues with several manufacturers MC4 plugs via efficiency testing and also some panels which had scratches that while super hard to spot were bringing performance down subtly.
These kind of issues can present on transporting the panels to site and in storage pre delivery. Equally damage can occur while mounting the panels to the roof that without a detailed efficiency tests is hard to spot and evidence wasnt in place at the point of installation without an efficiency test.
It is assurance for clients and contractors. One we are glad to offer on every single job.
Are you an installer?
@@deang5622 I guess that depends how you see it. Tomatoe tomato