Do solar panels work in winter?

Will solar panels work in winter? This recurring question not only has an answer but is also accompanied by a series of tips to improve the efficiency of photovoltaic technology during the winter months. Experts from ENEA (Italy's National Agency for New Technologies, Energy and Sustainable Economic Development) have released a statement detailing various measures and good practices to adopt during the coldest season to maximise the performance of photovoltaic systems. Let’s find out more.

How to use photovoltaics in winter

According to Nicolandrea Calabrese, head of ENEA’s Laboratory for Energy Efficiency in Buildings and Urban Development: “Photovoltaics can be an effective solution for saving on energy bills and protecting the environment, even in winter. When combined with electric heat pumps, they can help heat indoor spaces.” However, Calabrese also emphasises that it is “essential for a qualified professional in the sector to design the system.”

ENEA experts clarify that photovoltaic systems work well even in winter because the energy produced depends on sunlight rather than the intensity of the sun's heat. However, during the colder months, systems produce less energy due to shorter daylight hours and a higher frequency of cloudy or rainy days.

“In winter, it’s necessary to rethink how you consume energy. In summer, paradoxically, it’s less important to ‘know how to use’ the system since it produces energy for many hours a day and generally isn’t affected by adverse weather conditions,” explains Calabrese.

Photovoltaic performance in winter

Based on ENEA’s findings, a standard 4.5 kW domestic photovoltaic system on a typical November day achieves peak power output between 11:00 and 14:00, while it stops producing energy after 16:30. Additionally, it was found that by 12:00, the energy storage system is usually fully charged, meaning it is advisable to consume all the electricity produced from that point onwards.

For those with a photovoltaic system, even with energy storage solutions, it is crucial in winter to synchronise production and consumption. Using smart home solutions, such as scheduling electric heat pumps to operate during peak daylight hours, can help optimise energy use for heating, even if no one is at home.

“If we limit the use of a domestic photovoltaic system to the summer months only, the payback period for the investment becomes longer. However, if the system is efficiently managed in winter as well, it’s possible to recover the costs within approximately six years,” concludes Calabrese.