Thermal solar panels: what efficiency in winter?

With the rise of renewable energies, solar panels are emerging as an essential solution to address current energy challenges. In particular, thermal solar panels are generating increasing interest, especially for their ability to produce energy even in winter. In this article, we will explore the performance of thermal solar panels during the cold season, recent innovations, and how to maximize their efficiency throughout the year.

Understanding the operation of thermal solar panels

Thermal solar panels, unlike their photovoltaic counterparts, use the heat of the sun to heat a heat transfer fluid. This fluid, often water, is then used for water heating and home heating. Their operation is based on the principle of heat absorption, which means that even on cloudy days, these panels can produce energy, although with reduced efficiency.

Performance of thermal solar panels in winter

The performance of thermal solar panels decreases in winter, primarily due to reduced sunlight and lower temperatures. However, they continue to operate and can effectively contribute to heating, especially on sunny days.

Here are some factors influencing performance in winter:

• Sunlight: In winter, sunlight is weaker, which reduces energy production.

• Outdoor temperature: Lower temperatures decrease system efficiency, although they can still collect heat.

• Snow: Snow can cover the panels, temporarily stopping their operation, but as it melts, it can even clean them.

Innovations and technologies of thermal solar panels

In 2025, the solar panel sector experienced several technological advancements that optimize their performance, even in winter. Companies like Soleil Vert, SolarPack, and Soleil Energie have contributed to this progress by developing more efficient systems.

High-performance panels

New thermal solar panels incorporate advanced materials that enhance their ability to capture heat, even when it's cold. For example:

• High-reflectivity panels: These panels use surfaces that reflect less heat, improving their efficiency.

• Double glazing technology: Helps better insulate thermal panels against the cold.

• Composite materials: Resistant to weather fluctuations and humidity.

Hybrid panels

Hybrid solar panels, which combine photovoltaic and thermal technologies, offer an even more interesting solution for performance. They can produce both electricity and heat, thus maximizing the use of climatic conditions.

Maximizing the efficiency of solar panels in winter

To ensure the best performance of your solar installation during the winter months, it is crucial to consider several parameters.

Regular maintenance

Regular maintenance, including cleaning the panels and checking their condition, is essential. Snow and dirt can significantly reduce their efficiency. In extreme winter conditions, it is wise to check the surface presentation of the collectors.

• Regularly check for snow accumulation.

• Ensure that the pipes are not frozen.

• Inspect the mounting system to ensure proper stability.

Proactive energy consumption management

Offsetting the reduced performance of solar panels in winter requires thoughtful management of your energy consumption. Plan energy-intensive tasks during the day when the sun is shining:

• Use the washing machine or dishwasher in the middle of the day.

• Schedule your water heating during sunlight hours.

• Adjust cooking times to take advantage of the produced energy.

Financial aid for solar panel installation in France

To encourage the adoption of solar panels, several financial aids are available in France. These incentives aim to reduce installation costs and promote the use of renewable energies.

To benefit from these aids, it is advisable to inquire with local authorities and professionals in energy renovation such as Osmose Energies and Photowatt.

FAQ

• What is the best time to install thermal solar panels?
  We recommend installing solar panels during sunnier months, but it is possible to install them year-round.

• Do thermal solar panels work on cloudy days?
  Yes, although with reduced efficiency, they continue to produce heat.

• How do I clean my solar panels in winter?
  It is important to gently remove snow and clean the panel surfaces to avoid loss of performance.

• What are the installation costs of thermal solar panels?
  Costs vary depending on type and surface area, but for a standard system, expect to pay between 4,000 and 8,000 euros, not including aids.

• Can I benefit from aids for the installation of solar panels?
  Yes, various financial aids exist to reduce the initial cost, it is advisable to inquire about current government incentives.