Developer
IB Vogt Group
Duration of the project
The project is ongoing
Special challenges
Soft ground forced changes in working methods
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Careful scrutiny of the area was needed before work on the solar farm could commence
Finland’s largest solar farm will be completed in Kalanti, Uusikaupunki, in 2025. German ib vogt Group acts as the developer of the project. Jiitee Työt will implement a significant share of the project as a subcontractor. In the coming years, the amount of solar power produced in Finland will increase many times over. Like all the other Nordic countries, Finland is also a growth market for solar energy. Many companies are currently building or have commissioned the construction of large solar farms across the country.
The foundation work for solar farms needs to be designed and carried out by professionals, which is why Jiitee was included in the project. The construction of solar farms is very similar to other piling work, and requires the proper equipment. The solar panels for the solar farms must be anchored securely to the ground, so that they withstand harsh outdoor conditions all year round. The anchoring can be carried out in different ways, depending on the
- soil conditions (e.g., a rock close to the surface or particularly rocky ground)
- location (e.g., restrictions concerning the area, such as a prohibition to work on the land)
- snow and wind loads
- costs (sometimes the requirements for the brackets are so strict that building a solar farm is no longer economically viable).
Jiitee was chosen for the task because of the company’s equipment—the machines used in rock drilling are also ideal for laying foundations for solar and wind farms. Driven piles were selected for mounting the solar panels in the Kalanti project. Piling was difficult in places owing to the very soft ground.
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Drilling holes
1
Installing modules
1
Size of the area (hectares)
2
Soft ground challenged Jiitee to find new methods
The area of about 200 hectares where the solar farm will be built consists of forest, low-productivity forest, unproductive land and partial marshland outside the city of Uusikaupunki. The brackets for the solar panels were to be mounted by pile driving. However, because of the rock, it was impossible to drive the piles straight in. Holes larger than the piles had to be drilled in the rock first, and then the holes needed to be filled with gravel before driving the piles into place.
The drilling started in the winter, when ground frost and sub-zero temperatures made the soft ground at least partly frozen and hard. Nevertheless, a 20-tonne machine sinks into the ground quite easily when it comes across a spot that is not frozen. Even though Jiitee was using steel bridges and blasting mats to get the machinery across, the machines still got bogged down from time to time. Getting them back onto solid ground took quite some time, which also meant that the drilling needed to be stopped for the duration of the process. Another machine had to be used to pull the sunken machine to firmer ground. When a 20-tonne machine sinks to a depth of 1.5 meters, it can easily take a whole day to free it.
Of course, the challenges posed by the soft ground had been identified in the initial survey. Jiitee’s team visited the area before starting the actual work in order to select the right methods and machines and decide on the sufficient number of workers for the job. So, the soft ground did not come as a surprise, but caused a great deal of extra work nevertheless.
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Working on the solar farm required developing new methods quickly
Jiitee’s job involves drilling around 115,000 holes and driving piles in them. At the beginning, there were two machines, four workers and a supervisor at the site. Since then, the number has risen to 16 workers and four supervisors. Some drill holes and drive piles while others mount the solar-panel brackets. In projects such as this the schedule is always tight, but Jiitee can meet the requirements – work was carried out in two shifts a day.
The challenging nature of the site was known from the start. All working methods had to be developed specifically for this project, as Jiitee had never been involved in one like this before. However, this was no problem at any point, as Jiitee’s team is highly flexible and can adapt to new situations very quickly. Jiitee’s rock and tunnel construction expertise and equipment are also extremely useful in laying foundations for wind and solar farms. In every project, Jiitee works closely with the client and proposes many construction ideas and solutions early on. The final working methods are always selected based on the project’s requirements.
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Number of solar farms increasing in Finland
Despite its northern location, Finland is highly suitable for the utilization of solar power. This is reflected in the significant number of large solar farm projects underway nationwide. As an energy source, solar power is inexhaustible and provides many benefits:
- Solar power reduces dependence on fossil fuels and improves energy self-sufficiency.
- Solar power does not produce greenhouse gas emissions, making it important in mitigating climate change.
- With the right partner, designing and building a solar power plant is a quick process.
This project will not be the last of its kind for Jiitee. The team is ready to take on similar projects. One such project is the installation of 58,000 solar panels in a solar farm completed in Rauma. In that project, Jiitee worked as a subcontractor, mounting the brackets for the solar panels using screw piling and installing the brackets and panels. The main contractor was Suvic Oy.
More information on the projects
Lassi Levaste
+358 44 215 7469
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We are able to work even in the most demanding conditions and if necessary, innovate completely new solutions to efficiently carry out the work. So don’t hesitate to contact us when you need a professional on site.
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