Sunday, March 19, 2023

How To Check Solar Panels Are Working

Look At The Inverter Is There A Red Or Green Light

How To Test Your Solar Panel – Quick And Easy

Many solar owners never go near their inverter, but CHOICE found that 20% of surveyed solar owners had experienced problems with it.

How would you know if there’s a problem? A simple health check is to look at the colour of the lights shining on the box during daylight hours when the system’s meant to be running.

A green light on your inverter means your system is functioning properly. A red or orange light during daylight hours means there’s a system event orfault.

In the event of a red or orange flashing flight, look for an error code on the display. Alternatively, you may be able to go to the inverter’s user interface via a web portal for an indication of the cause.

Finn Peacock from Solar Quotes says, “If there’s an error message, call the installer.”

Inverters can shut down due to a grid fault where the voltage is too high or too low, or there may be a problem with the earthing of the system. Another reason might be that the circuit breaker for the inverter has tripped.

More specifically, in the case of newer SMA brand inverters, a green light on the outside of the inverter means there is above 90% output . Below 90% and the light pulses.

Older generation SMA brand inverters may not have an online interface and may use a yellow light instead of a red one to indicate a fault.

How To Check Solar Panels Are Working

We constantly get calls from solar system owners, who think their solar is not performing as it should, but really have no idea whether it is working properly or not.

A lot of people ignore their solar until they get a bill, when they are either happy with the result, or they either find out the system has stopped working, or they havent got as many credits as they believe they should. How do you know whether or not you do have a problem?

4. Check the solar has performed as it should

To Measure Short Circuit Current Amps :

  • Disconnect the solar panel completely from the battery and regulator
  • Angle the solar panel towards the sun.
  • Ensure that the multimeter is set at 10A, at least to start with. You can change the setting later if required.
  • Measure the current by connecting the +ve lead on the voltmeter to the +ve on the panel and the -ve from the voltmeter to the -ve on the panel

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The Difference Between Power And Energy

Power is measured in watts or kilowatts . Energy is measured in kilowatt hours . If your solar panels continuously output 5kW of power for a whole hour, you will have produced 5kWh of energy.

Not sure if it is working as it should? Give us a call on 1300 130 546 for professional help

Fronius Solarweb Graph

How To Test A 12 Volt Solar Panel

A glimpse into how solar panels work

Because most solar panels come with a 12v rating, they are the most common to test. Basically, you test a 12v solar panel like other voltages.

Ensure the meter is set at 200 volts DC before you start. An overload means you need to turn up the volts DC. Once you have everything right, you will get a proper reading.

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How To Test Solar Panels

In some cases it can be easy to determine the cause of a reduction in solar output. For example, you wont need to know how to test solar panels if a nearby tree has grown and is now casting shade on your panels.

In many cases, it isnt so straightforward. So, lets go through some ways to test your solar panels.

Solar Panel Short Circuit Current Test

This test is performed to check the degradation of the solar module its a direct test of the solar panels ability to deliver power. You need to check that the maximum current possible doesnt exceed the multimeters maximum current reading. Connection should be quick to minimize any arcing very possible with high-power panels.

The Isc Test should be done on the single panel on a sunny day and the current kept around 10 aps or less.The resulting current reading is directly proportional to the amount of sunshine and its a great idea to use solar radiation or power meter to measure the suns energy. If the value is particularly low, it can be used to adjust the readings obtained when determining the power rating.

Using the 10 amp setting on your multimeter connect each lead to the positive and negative terminals of the panel. Expect to see a value of not less than -20% of the stated rating after adjusting for insolation conditions.

Can a solar panel be short-circuited with no damage?

A solar panel wont be damaged by a short circuit. Solar panels are designed to be continuously operated at very close to their short circuit current. This is a good, easy test of a solar panel. The optimum operating point of a solar panel is typically about 90%+ of its short circuit current and about 70% to 85% of its Voc . This is when it delivers the most power.

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If You Have Online Monitoring Check The Performance On There

Many newer inverters come with online monitoring, ie Fronius/SMA. This is a really good way of seeing how your system has been performing, over time.

Here you can see an example of a graph you can get on Fronius Solarweb. Solarweb is the online reporting/ monitoring tool that is available with all the newer Fronius inverters. This graph is showing the number of kwh made for each day during the month of January.

Read Your Solar Meter

how to test a solar panel is working

Your solar meter monitors your systems production and shares this information with your solar company. Typically, your meter will cycle through different screens. You should pay particular attention to the one that displays the total kilowatt-hours that your solar panels are generating.4 As long as your kilowatt-hours are increasing, your solar panels should be working fine. If not, make sure to go through the previous steps before you call your solar company.

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Check For Shade And Dust On Solar Panels

Your solar panels function best when they can soak up all of the suns rays. If theyre obstructed in any way either from shade or dust they wont perform as well. When your solar system was installed, the engineers likely placed your panels in the best possible light. However, after a few years, there may be new tree growth that is shading either a small or significant portion of your solar panels.

If you notice new growth, call your arborist and have the branches removed. Track your solar production for about a week afterward to see if it increases, or if there may be another culprit behind the decline in energy production.

If your panels are in the perfect position to soak up sunlight, its possible that dirt, dust, or debris are affecting their energy production. Cleaning your solar panels is easy, and only needs to be done a few times a year. Its as simple as using your garden hose to rinse off each panel.

If a hose does not reach your panels, we recommend you contact a professional solar cleaning company – you should never climb on your roof to clean your panels.

Troubleshooting: Low Power Situation

If your solar system is not delivering sufficient power for which it is rated for, the resulting situation is called a low power situation. This is the most common type of problem and a few, quick, troubleshooting steps will help you find the source of the problem. The factors that could contribute to a low power problem are:


This is possibly the most common cause of low voltage. Ensure that there are no trees around and that the solar panels are not blocked by shadow at any time during the day. Keep in mind that a solar systems lasts for more than 25 years and trees grow over time. Conducting a bi-annual survey of the installation site is a good idea.


If shading is not an issue, most likely it will be the higher than normal operating temperature of the solar panels. It has been scientifically proven that the voltage drop rises with the rise in temperature. The higher the temperature, the lower will be the power output. Adding more modules in series, and therefore increasing the string voltage, will eliminate this problem. Also, make sure that theres sufficient air circulation beneath the panels and that this open space is not blocked in any way.

Bad Connections

Solar panel defects


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Frequently Asked Questions About Monitoring Your Solar System

What do I do if I lose solar monitoring?

For systems installed with a Tesla Solar Inverter, check that the inverter is powered on and connected to your home router or internet modem. If the Tesla Solar Inverter loses its internet connection, follow the troubleshooting steps to change network settings.

For systems installed with a third-party solar inverter, check that the solar Gateway provided with your Tesla solar system is powered on and connected to your home router or internet modem. It should also be within range of your solar inverter. If you see a ‘Weak Signal’ notification, move the Gateway closer to your solar inverter until the notification disappears or follow troubleshooting steps for support.

Can I monitor my solar system from my desktop?

Tesla provides the Tesla app for system monitoring and does not provide desktop or web-based monitoring. While monitoring is only available in your Tesla app, your Tesla Account is available to manage billing details and view documents and information from the ordering process. Youre also able to find access to additional support articles. To access your Tesla Account from the mobile app, simply click on the gear in the upper left corner and select ‘Get Support?’

Why can I not see my products on the Tesla app?

Solar Panel Voltage And Current Output Voc & Isc

How To Get Used/Working Solar Panels For FREE

Voc stands for the Open Circuit Voltage measured when the panel isnt connected to anything. Isc is the Short Circuit Current that flows when the panel leads are shorted together. It never sounds right to short circuit any wires coming from a power supply but in the case of a solar panel no long-term harm is done. Strangely enough, when the leads are short-circuited the voltage from the panel is zero lets take a closer look.

The figure below is Solar Cell I-V Characteristic Curves showing the current and voltage characteristics of a particular photovoltaic cell, module or array giving a detailed description of its solar energy conversion ability and efficiency. Lets discuss in some detail.

The I-V curve for solar panels. Courtesy

The image shows the relationship between current and voltage of a typical silicon solar cell cell with normal operating conditions. Solar cell watts or power is current multiplied by the voltage or I x V. If multiplying V and I at various levels from short-circuit to open-circuit conditions, its possible to illustrate graphically what the power generated is.

There wont be any current when the voltage is maximum because these are open-circuit conditions. Theres no circuit connections allowing current to flow. When a current does flow, it starts to drag down the solar panel voltage.

  • Max volts x zero amps = zero watts
  • Zero volts x max amps = zero watts

Before you start testing your panel

Standard Test Conditions

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What Is A Professional Solar Site Assessor

A professional solar site assessor is someone who has been trained to evaluate locations to determine whether they are a good fit for renewable energy projects. The MREA has a list, by state, of licensed site assessors for Solar Electric , solar hot water, and small wind. Some renewable energy rewards programs insist that you hire a professional site assessor before you can collect rewards. While it may sound unnecessary in some cases, this policy prevents unscrupulous installers from selling you a bad system that will never produce what you were told it would. Site assessor will often have specialized tools such as a Solar Pathfinder, Solmetric SunEye or Smartflower. If you do call for a professional site assessor, check with them to see if there is a local rebate program. Some site assessors are also installers and if you hire them to design and install the system they will credit you the cost of the assessment into the overall system cost. Dont hesitate to ask the site assessor those types of questions over the phone or via email.

Troubleshooting A Solar System

Below I will describe basic steps in troubleshooting a PV array. Quality solar panels are built and guaranteed to produce power for 25 years. For that reason, its most likely that a problem is caused by a defect in system components other than the panels, such as the solar inverter, charge controller, wiring or batteries. However nearly every pv manufacturer has seen defects in solar panels over the past years, and Ill also describe common quality issues that might shut down a pv module.

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Solar Panel Testing How

This instructional post not only shows how to test any solar panel but also what the tests mean in practical terms. The tutorial covers the basics of multimeter use up to the importance and practical use of voltage-current curves and the concept of MPPT .

Actual tests will be carried out on 100 watt flexiblemonocrystalline solar panel and a Dokio 80 watt folding solar panel using a 12 volt water heater as a load to determine voltage and current characteristics.

Im also going to carry out a couple of other interesting tests that you wont find anywhere else using a buck converter.

Second Solar Site Check Find The Right Roof Pitch

HOW TO | Know If My Solar Panels Are Working

The ideal system will also have a tilt angle of your latitude 10°. In Madison, where I am, we are at 43° north, so my system should aim for 33° tilt. The idea is to maximize output during the longer days in summer. If your roof is a 4-12 pitch, it converts to 18.5°. That is fine.

Raising the back edge to increase the tilt angle will only gain you a few extra percent of production at the expense of higher wind loading. More wind load means more structural stress and more supports. The extra cost exceeds the production gains. It also means more roof penetrations and potential leaks. Even a flat roof can be a good location for P-V. A roof that is greater than 45° would not be ideal.

I will use my old house as the example for this article. The roof had a 5-12 pitch or 22.5°. The main ridge of the roof is north-south, but the house had a 3-season porch off the back that has a south-facing roof. The lower edge is only 17 and there is 11 of vertical space. That may not seem like a lot, but it can still be productive.

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Look At Your Generation Meter

Check the generation meter’s display is visible, & the indicator light is flashing . Be sure to check during daylight when the system should be generating.

  • If the generation amount on the meter isn’t increasing as you’d expect each day, there’s probably a fault.
  • The more frequently the indicator light flashes, the more the system’s generating.
  • If it’s permanently lit during the day, the PV system’s probably not working.

How Do You Check Polarity Without A Multimeter

However, if those arent available to you either, then here are steps to do this: First, cut off power going into the DC circuit breaker box by switching off the corresponding switch.

Then remove covers protecting wiring terminals where leads from PV modules enter the house. Now attach positive probe onto the terminal with a red wire coming out and negative probe onto other side attached with black wire.

If both probes read positive voltage, this side of the generator has positive charges, and negative charges are on the other side!

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Don’t Rely On Your Electricity Bill

We found 46% of solar owners use their bill to see if there’s a problem – but this is unreliable. Looking at the amount of money you received for your exported solar doesn’t give a good idea of the performance of your investment.

Your bill doesn’t show how much energy was produced by the PV system in total, or how much of that was used in the house it only shows the amount of solar energy exported to the grid, and the amount of electricity you’ve drawn from the grid.

If something goes wrong with your system and the output is reduced or the inverter has an error and stops working, the grid quietly steps in to provide the power instead. Many of us only receive electricity bills every three months. That’s a long time for a system to be on the blink and losing you money.

In addition, the output of solar systems change with the seasons as the hours of available sunshine lengthen or shorten. And with a change in the seasons, our household usage patterns also change. So quarterly electricity bills aren’t easily comparable.

Shaded panels. Image courtesy of Christian Anderson.

How To Diagnose Solar Panel Problems Before They Impact Your Savings

How Do Solar Panels Work? â Solar Energy Guru

The checklist above will help you resolve 80% of most solar-related issues. And itâs a good idea to run through these steps periodically since dust accumulation, pest infestations and tripped switches are all inevitable over the 20 to 25 years of your panelsâ warrantied lifetimes.

But if youâre truly interested in protecting your clean-power investment, solar monitoring represents the simplest and most hands-off approach for diagnosing when and why your solar panels are not working. Once set up properly, solar monitoring can track your PV systemâs performance and send out alerts when intervention is necessary.

To learn more about our comprehensive solar service & membership plans â or to have us troubleshoot an issue not on this list â contact us directly using our contact form.

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