There can be several reasons why your solar panels are not producing as much as hoped. Sometimes it’s due to something simple like dirt or shade, but it can also have to do with the installation or the weather. In this blog, we list the most common causes. That way you know what to look out for and when it’s time to have someone look at them.

Why are my solar panels producing less than expected?

You had solar panels installed with the idea of saving substantially on your energy costs. But after a while you notice that the output of the solar panels is disappointing. Perhaps you see it reflected in the app or on your energy bill. This is obviously disappointing, especially if you had counted on higher results. Before you worry, it’s good to know that there can be several causes.

Sometimes it’s due to something simple, like dirt on the panels or shade falling across your roof later in the day. But it can also have to do with technology: an inverter that isn’t working properly, a mediocre connection or panels that aren’t aligned quite right. Weather and seasons also play a big role. In doubt about less yield from your solar panels? Then have someone knowledgeable take a look.

Shading, dirt or aging: these affect your panels

Solar panels work best when they get lots of sunlight. But sometimes your roof gets shaded, such as by a tree, a chimney or a dormer. Even if it’s just a little shadow, it can cause your panels to work less well. As a result, the yield from your solar panels may be disappointing and you may find that you get less energy back than you expected. It is therefore smart to regularly check if anything has changed around your house, such as trees that have grown.

Dirt on the panels can also be a problem. Think dust, leaves or bird droppings. This blocks sunlight and causes your panels to make less power. Especially on flat roofs, dirt sometimes remains, making the situation worse. In addition, solar panels become weaker after a number of years. This means you can expect less output from your solar panels over time. It’s good to keep an eye on this so you know when maintenance is needed or when it’s time to replace panels.

Seasons and weather: how much sun can you really expect?

Solar panels work best when the sun is shining, but how much sun you can actually expect depends greatly on the weather and seasons. In spring and summer, the days are longer and the sun shines more often, which means your panels will generate the most energy. In the fall and winter, the days are shorter, cloudy and it can even snow more often, so the yield from solar panels can be disappointing. This is quite normal and part of using solar panels.

Many people find it difficult to understand why they see less solar panel output in some months than in others. Therefore, it is better to look primarily at the yield over an entire year. Usually the sunny months in spring and summer make up for the lesser yield in winter.

When is it time to get help?

If you think, “the yield from my solar panels is disappointing,” it can sometimes cause doubt. Fortunately, in most cases there are good solutions. Have you checked everything, such as shade, dirt and seasonal influences, but the yield remains low? Then it’s still smart to call in a specialist. Especially if you notice that your inverter is not working properly, your installation is older or if you have doubts about the correct operation of the system.

A professional can use special equipment to properly measure your solar panels and installation and detect any problems. This way you prevent small defects from leading to an even lower yield. They can also advise you on maintenance or improvements that can increase the lower yield of solar panels. So don’t wait too long, because with professional help you will get the most out of your investment.

Why do I need to measure/monitor the output of my solar panels?

By regularly monitoring the yield of your solar panels, you will always have a clear overview of what they are producing. But yield is not the only reason to measure your solar panels. In fact, measuring/monitoring also allows you to identify problems with the panels more quickly.

So how do you recognize a problem? If you check the yield regularly, you will see that it is fairly even. If, when measuring the solar panel yield, it suddenly appears that the yield is falling while there is no logical explanation (such as bad weather conditions) for this, it could mean that there is something wrong with the panels.

The solar panels may be faulty or the inverter may no longer work properly. Inverters normally last about twelve to fourteen years. However, they can lose efficiency before that. Thus, you may need to replace the inverter to get back more yield from your solar panels and measure it.

How is the yield of solar panels measured?

Measuring and monitoring the output of solar panels can be done in several ways. The easiest method of measuring solar panel yield is to use the inverter. Every solar panel installation comes with an inverter. This box can convert the energy generated into electricity.

On the screen of the inverter, you can read the power and yield of the panels. Usually the yield is displayed per day and per total. On some inverters, you can even see entire graphs of daily, monthly and yearly yields. Nowadays, most inverters can be linked to Wi-Fi, allowing you to easily view the output of your solar panels in an app.

Methods of measuring the yield of solar panels

Apps

Als u zonnepanelen in Limburg heeft aangeschaft via De Duurzame Jongens, dan kunt u gebruikmaken van onze handige app om de opbrengst van uw zonnepanelen te meten. Via de app kunt u namelijk realtime de energieopbrengst van uw zonnepaneleninstallatie bekijken. Met een slimme meter kunt u ook gelijk zien hoeveel stroom er wordt opgewekt, wat u aan energie verbruikt en wat u terug levert. Op deze manier krijgt u veel meer inzicht in de totale opbrengst van uw panelen en kunt u verschillende periodes met elkaar vergelijken.

In addition, the app can also give you insight into the operation of your system. If the solar panels are not working properly, you can see that right away in the app. We are also notified if the panels purchased from us are not working optimally. We can then look for a suitable solution together.

Monitoring via een omvormer

Another way to measure the output of your solar panels is through the inverter. This can often be linked to Wi-Fi for insights you would like to get out of it, think consumption by day, month or year.

Gebruik van een energiemeter

A P1 meter or energy meter gives you insight into what is delivered back to the grid. By linking it to the data from the inverter, the total yield can be monitored. Please note that a P1 meter usually measures feed-in but not the total yield.

Externe meetapparatuur

For more technical measurement, measuring voltage and current is possible with a multimeter. Such monitoring systems use data loggers with voltage and current sensors to calculate the yield in W/kWh.