Do solar panels work on a cloudy day?

This is a question we are often asked at Blackwell Energy and is a very common concern that many Irish homeowners have before switching to solar. It’s true that cloudy weather can indeed impact the efficiency of solar panels, but there’s no need to worry. Solar photovoltaic cells can continue to operate at an impressive 80% of their maximum output even during partly cloudy weather. Because solar PV panels don’t require direct sunlight, but simply daylight, the type we often receive even on cloudy days. Therefore, even when it’s cloudy outside, your solar panels will continue to generate energy. It is understandable why this may be a question on the minds of potential buyers, considering the unpredictable nature of the Irish climate. Rest assured, on cloudy days, your solar system is still able to generate a considerable amount of energy.

Effect of rain on solar panels

Just like cloudy days your solar panels will also work on rainy days and will still produce electricity. In fact, even heavy rain doesn’t completely hinder solar panel performance, as they still produce about 20%-30% of their optimal output. If you have solar water heaters installed on your rooftop, you can still have access to hot water even during overcast or rainy days. However, continuous days of cloudy weather can decrease the efficiency of your solar-heated water. Despite this, solar panels can still be utilised even on partially cloudy days, as they can perform at about 80% of their maximum power.

It is important to note that while clouds may reduce the amount of sunlight that reaches your solar panels, it doesn’t block it completely. In fact, rainy weather can aid in keeping your panels clean by washing away dirt and dust. If you experience many days of overcast or cloudy weather, you may notice a decrease in your solar panels’ effectiveness since fewer elements of light can generate significant electrical power but over all the solar panels still produce power, reducing your dependance on the national grid.

Temperature effects on solar panels

Living in a country with a climate like Ireland can actually benefit you greatly when it comes to solar power. Many people are unaware that the efficiency of solar panels decreases as temperatures increase. As the temperature of a PV panel goes above 25°C (77°F), the efficiency of the panel decreases because of the temperature coefficient. The coefficient measures the degree to which the output of power decreases for every one degree Celsius temperature rise above a reference temperature (usually 25°C).

When the temperature increases, the semiconductor materials in photovoltaic cells become more conductive, which increases the flow of charge carriers and reduces the voltage generated. Fortunately, some PV panels feature methods to dissipate heat to counteract the adverse effects of high temperatures. Passive cooling and enhanced ventilation are two examples of proven mechanisms that can bring solar panels closer to their optimal operating temperatures. By taking these steps, you can maximize the efficiency of your solar panels and significantly reduce your energy bill.

Summary

Our climate in Ireland provides great results when it comes to powering you home from solar. With updated solar technology even on cloudy average temperature days we can expect to make significant savings on your energy needs. For more information on the benefits of solar check out our article Is solar worth it in Ireland