As solar panel efficiency has increased and prices have continued to fall, individuals and businesses have considered utilising solar panels to offset rising energy bills. Aside from the obvious benefits of reduced energy bills, business owners and individuals have the added benefit of becoming more eco-friendly.

However, a common concern, especially in countries such as the UK with mixed weather conditions, is whether the panels will generate the necessary returns on cloudy days and in the winter. There are many occasions whereby solar panels will not get direct sunlight, so it is important to understand how this will impact the electricity generation from the system and the potential savings.

Solar panels not being installed in direct sunlight

There are two types of sunlight which typically must be considered when installing solar panels as each type of sunlight will impact electricity generation from the system.

Direct sunlight – Direct sunlight (direct beam solar radiation) is directly from the sun and has no interruption or objects between the sun and the system.

Indirect sunlight – Indirect sunlight (diffuse solar radiation) is typically where sunlight is bounced off surrounding objects before hitting the system.

Solar panels produce electricity from photons, which are contained in both direct and indirect sunlight. While solar panels will continue to generate electricity with indirect sunlight, they will be at their most efficient in direct sunlight. When installing solar panels, placing the panels in direct sunlight is the optimum set-up, however, it is possible to mitigate the impact of indirect sunlight on the rest of the solar array.

Does shading affect solar panels?

In short, yes, shading does impact electricity generation from solar panels. However, that is not to say that solar panels don’t work in the shade and several technologies can reduce the impact that shading has on the system.

  • Shading duration

The longer the panels are shaded the more impact it will have on the electricity generation of the panels. Ideally, panels that avoid shading

  • Panel technology

Newer panels use technology such as half-cut cell technology, which are designed to reduce the impact of shading on electricity output levels. With more traditional solar panels that don’t use these types of technology, shading can have more of an impact on output levels.

  • Inverter setup

Depending on the types and set-up of solar panels, shading on one panel can impact all of the solar panels within that string i.e. if the output of one panel is reduced to 40% due to shading, all other panels within that string will also be reduced to 40% efficiency. Utilising microinverters or organising the strings into panels that are and aren’t shaded will minimise the impact of shading on electricity output which will increase returns and reduce payback time.

Solar panel generation in the winter

Winter typically comes with greater levels of shading, caused by bad weather, leaves, snow as well as shorter and lower light conditions. During the winter months, there are typically longer levels of indirect or no sunlight, with electricity generation in these periods either being reduced or non-existent. As such, electricity production from solar panels in the winter months will be reduced from the yields that are produced during the summer months.

To offset and minimise the impact of indirect sunlight and reduced electricity generation from solar panels, ensuring the panels are clean and free of any dirt or leaves will help improve generation. During the installation and feasibility stage, any shading and yields from the winter months are typically considered when assessing solar panel yields and therefore financial feasibility of the system.

Solar Panels at SolarTherm UK

At SolarTherm UK, our expert team of installers and designers ensure that any solar panel system installed is designed to work at its maximum efficiency, therefore also maximising the potential savings from the system. Our team typically conduct a desktop survey where we will assess the viability of the system while also assessing potential shading issues. To find out more about solar panels on your property or to get a quote, contact our team today.