Tomatoes grown with renewable pellet heating

 

The family business is a busy operation, running seven days a week from March to September. Their days are filled with caring for the plants, managing pests, harvesting tomatoes, packing and selling produce, and keeping the café running.

Eva’s mother is still actively involved in the business. She bakes all the bread served at Café Pomodoro during the summer season. And naturally, pomodoro means tomato.

The greenhouses were originally heated with oil, which was the recommended choice when Eva’s parents first invested in the operation. At the time, established technology was considered the safer option.

Ten years ago, Eva’s parents made the decision to replace oil with locally produced pellets, significantly reducing the business’s reliance on fossil fuels. The conversion was relatively straightforward, as the existing oil boilers could be fitted with pellet burners.

“Purpose-built pellet boilers would provide even better performance, but for a small family business that represents a major investment,” says Jorge.

The greenhouse heating system consists of three boilers, all fuelled by pellets. Two 200 kW pellet boilers distribute heat throughout the greenhouse via fans. The third boiler provides underfloor heating and is the first to be started each season. The soil in the greenhouses is warmed first, followed by the containers in which the tomato plants are grown.

orge explains that they have never used chemical pesticides. Instead, they rely on biological pest control, introducing beneficial insects that help keep harmful pests under control naturally.

Water and nutrients are supplied to the growing containers through a pipe system. One of the advantages of using growing containers is the ability to precisely manage nutrient delivery to the plants and recover excess nutrients. Any surplus nutrient solution is collected from the containers and returned to storage tanks, where it can be reused.

“We don't use organic fertiliser yet, but the fertiliser is part of a closed-loop system, allowing us to recover and reuse it while reducing emissions to the surrounding environment,” says Eva.

A lot of buzz at the local shop in Ljustorp

Bumblebees play an important role in pollinating the tomato flowers. So how do you attract bumblebees into the greenhouses?

“We simply order them online, and they arrive in packages at the local shop,” Eva says with a smile.

When SCA visited in September, all that remained was to let the final tomatoes ripen. After that comes a period of maintenance, cleaning, and a well-earned holiday before the next growing season begins.

The greenhouses are left unheated during the winter months. According to Eva, a few days of temperatures as low as -20°C are actually beneficial, helping to eliminate any pests that may have survived the seasonal clean-up.

By March, the pellet silo, which holds 16.5 tonnes of pellets, needs to be fully stocked. The growing season begins by starting the ground heating loops and gradually warming up the greenhouse. New plants are then delivered, and the seedlings they have raised themselves are set out.

“The aromas are wonderful, and greenhouse life begins again,” says Eva with a smile.

Throughout the season, the temperature inside the greenhouse must be maintained at a minimum of 18°C.

“The pellet deliveries from SCA work well, and so far we've never failed to keep the temperature where it needs to be,” says Eva.