Aerial view of HögforsGST's factory and its solar power plant

The energy system at HögforsGST’s new factory is one of its kind: the unique HybridHEAT system utilizes the best of both heat pump technology and geothermal energy. The factory’s crown is a large solar power plant, which produces more electricity than the building consumes. The new factory is therefore a modern zero-energy building.

HögforsGST’s new factory, built in Leppävirta in the spring of 2020, stands in the immediate vicinity of Highway 5. An investment of 5 million euros became necessary as the former production space was getting too small to meet the growing demand. According to Managing Director Antti Hartman, the need for smart energy solutions is greater than ever.

– The fight against climate change and willingness to invest in energy efficiency are significant drivers of demand in whole Europe. At the moment, about half of our sales come from exports and further growth is expected. More production space is really needed, Hartman says.

In addition to growing demand, HögforsGST also wanted to address the challenges of improving energy efficiency without compromising working conditions. The idea of ​​an energy-efficient heating and cooling system was born, in which energy is produced with the combination of heat pumps and geothermal energy. The system in HögforsGST’s new factory, which is built according to the company’s own HybridHEAT concept, produces both heating and cooling. The electricity needed by the system is generated by a large solar power plant installed on the roof of the factory. The end result is a zero-energy building filled with modern energy solutions.

HybridHEAT is HögforsGST’s flagship technology, which combines multiple energy sources into a seamless system

Heating in the winter, cooling in the summer – an efficient heat pump is the heart of the system

The new production facility is a completely air-heated space, in which heating and cooling is produced by an efficient heat pump. Juha Virkki from HögforsGST talks more about the system.

– At the heart of everything is a heat pump that produces heating or cooling, keeping the building’s internal temperature and working conditions optimal. The system also utilizes exhaust air heat recovery in energy production. Of course, the recovery system works both ways: in the summer, the system recovers cooling energy from exhaust air, Virkki says.

The heat pump is the main source of energy, but its power alone is not enough to meet the energy needs in the cold winter. In this case, it is time for geothermal energy to step in.

– Although the building is insulated better than a normal building, the heat pump occasionally requires additional energy to keep the conditions optimal. In this case, energy is taken from the geothermal wells to support the heat pump system. The geothermal wells also act as heat storages, as the summer heat stored in the ground can be used for heating in the winter. This system also works both ways: the geothermal wells also act as storages for cooling energy, Virkki reminds.

The production of heating and cooling is thus handled by a combination of heat pump, heat recovery and geothermal energy. According to Virkki, the system has also included several other features that improve energy efficiency.

– For example, ventilation’s heat exchangers are designed for low temperatures, which significantly improves the efficiency of the heat pump. The system also features our new, more efficient heat recovery unit. Multiple sensors produce data from the system’s operation, so the system can be monitored and controlled via our own Fiksu Control System, Virkki says.

Antti Hartman describes the new plant as a giant test lab where the technology developed by the company can be tested in practice before being launched on the market.

– The new production plant is like a giant test laboratory where we can test the functionality of our inventions. Number of sensors provide accurate information on the operation of heating and cooling in different conditions, which allows us to develop our products. In this particular system, for example, we are following the performance of our new heat recovery unit very closely, Hartman says.

The system has been tested in rather extreme conditions, as on the coldest days of winter, the temperatures have dropped to -30 degrees Celsius. During the hottest periods of the summer, the temperature in Leppävirta has risen to +30 degrees Celsius.

Emission-free electricity powers HögforsGST’s new factory

In addition to the innovative and energy-efficient heating system, the new plant is a zero-energy building thanks to its own energy production. The literal crown of the energy system is a 702-panel solar power plant mounted on the factory’s roof. The 200-kilowatt solar power plant is among the largest in the region and generates about 150 megawatt-hours of electricity per year. This is equivalent to the annual electricity consumption of about 74 Finnish apartments.

Aerial view of HögforsGST's factory and its solar power plant
Large solar power plant is the cherry on top of a modern energy system

According to Virkki, the amount of electricity produced by the solar power plant corresponds to the amount of energy consumed by the building, making it a zero-energy building.

– The new plant is a zero-energy building, as the power plant’s production covers the electricity consumed by HVAC and other systems of the building. Production and consumption are distributed slightly to different seasons, but across the whole year, production matches consumption, Virkki says.

During the sunny summer season electricity is generated more than needed. This is good news for the company, as the summer and autumn are the high seasons for production. This means that the solar energy can be utilized in HögforsGST’s manufacturing process. If there still is leftover energy from the manufacturing, it can be either sold or used otherwise.

– During the construction of the factory, we also installed six charging stations for electric cars. Therefore, electric cars can be charged with solar electricity produced in our own power plant. In the evenings and on weekends, when the factory’s consumption is low, the excess energy is sold to the electricity company. However, most of the electricity produced in our plant goes to our own use, Hartman says.

Hartman estimates that the savings generated by the solar power plant are thousands of euros annually when self-produced energy can be used instead of purchasing electricity. More important than financial savings, however, is the impact on the company’s CO2 emissions: HögforsGST’s annual CO2 emissions are reduced by 90 tonnes.

Flagship technology and increased competitiveness

As mentioned, the demand for modern energy solutions is growing strongly, and HögforsGST’s new factory was built to meet this demand. According to Antti Hartman, the new plant will not only bring more production capacity, but also improve the company’s technological competitiveness.

– With the new factory, we have even better opportunities to test and develop new solutions in a controlled environment. While the new factory has a space dedicated to product development, the entire building serves as a large test lab when needed, as the current heating system shows, Hartman laughs.

Optimal working conditions, a smart heating and cooling system and a large solar power plant are the three most important features of the new factory, Hartman says. At the same time, it serves as an example of how heat pumps, geothermal energy and solar energy can be integrated into a seamless system.

– The factory building is like HögforsGST’s flagship technology showroom, where the versatility of the HybridHEAT concept is showcased at its best. I am very proud of the hybrid system at our new plant, Hartman concludes.