Specifics of PV installation in the winter months in northern Europe

We consulted our site managers, experienced in Scandinavian projects, for insights on working in these natural conditions.

Frost and wind

Snow and frost greatly impact our work, with northern temperatures ranging from +5 to -20°C. Construction sites face higher risks of injury, accidents, frostbite, or colds due to the ice and cold. Acclimatization and specific work equipment, such as headlamps, heel traction aids, and gloves, are essential.

Strong winds in northern climates also pose challenges, and we have to take extra care when distributing materials and placing solar modules, especially when installing rooftop solar power plants.

Surprisingly, winter weather can also be a small advantage, as frozen ground is hard enough for material and equipment handling, while in higher temperatures there can be a problem with logistics due to muddy terrain. 

Subsoil and Groundwater

Construction takes place on sites with a variety of subsoils, ranging from hard clay to sandy soil and peat bogs to stony forest soil. This requires a special approach to each of these terrains. Unstable subsoils and wind risks make conventional ramming of steel profiles unsuitable. In peat bogs, preventive stripping and creating stable log platforms for extraction are often necessary. 

In addition, if there is a high water table that varies with the intensity of rainfall, the originally planned technologies may prove unsuitable. Drilling can often lead to rapid collapse of boreholes and the formation of caverns, requiring additional interventions such as excavator gradients to a depth where drilling is no longer possible.

Stones

Ramming often reveals large stones that excavators can't remove. We used a Swedish patented explosive, a compacted gunpowder charge, to remove a particularly large stone found durring ramming. Drilled into the stone, its activation causes internal combustion, as shown in the attached image.

Concreting in extreme temperatures

In unstable subsoils, we use the technology of pre-cast concrete piles, which serve as an anchor for the steel section and prevent uneven settlement of the structure. For concreting in the Swedish winter, freezing temperatures are a real disadvantage and pose a number of challenges. In temperatures down to -5 °C, antifreeze additives are added to the concrete. When the temperature drops even lower, we have to use a heated tent, where there are thermocouples connected to a weather station and a mobile app, thanks to which it is possible to monitor the temperature inside the tent and have good control over the hardening of the concrete. The tent is large enough to accommodate a mix of concrete and allow the molds to be cast in a temperate environment.

Weather and its traffic impact

Winter road conditions in the north are almost unpredictable. This is due to the proximity of the sea, which both warms and moistens the local climate. TDaytime temperatures around zero can lead to icy, frosty mornings. Often, more than 50 cm of snow will fall during the night. Locals are used to using studded tyres because of the ice that often forms on the roads. In general, driving in the north is often slower, and speed limits are lower for safety reasons. Traffic is thinner, and the locals are really disciplined and experienced drivers.
  

Light and time delay

Local light conditions hinder PV plant construction, as darkness falls in the early afternoon and requires a dependency on our headlamps.  The lack of light also affects the team's mood, requiring careful people management. Different time zones in northern countries pose additional challenges, necessitating exceptional organization to maintain work continuity between the office and the site.