8.1.2025
Juntti greenhouses grow their energy efficiency with heat recovery
Puutarha Timo Juntti Oy is a leading producer of greenhouse-grown cucumbers in Finland. This is not the first time Juntti has adopted new technology. This time, the greenhouses received a heat recovery system developed by Novarbo Oy, which improves their energy efficiency.
“This investment allows us to reduce our use of external energy, and we can use the recovered heat energy to heat our cucumber greenhouses for most of the year,” says Managing Director Tero Juntti.
The new technology captures the excess heat released by the greenhouses, storing it in large water tanks for later use during cooler periods.
“Now our greenhouses are self-sufficient for heat down to a few degrees below zero.” Juntti still needs external energy in colder periods.
Juntti also saves costs in summertime because the equipment regulates humidity and temperature all year round.
“The greatest benefit of the heat recovery system is minimising our need to ventilate greenhouses in the summer. If we don’t need to open the ventilation vents during the day, we can add extra carbon dioxide to the greenhouse, which directly improves the cucumber yields.”
Once heat recovery is combined with humidity control, the system becomes very efficient.
“This equipment allows the extra humidity in greenhouses to be condensed appropriately and used to water the plants,” says Tero Juntti.
Future greenhouses could become energy producers
Greenhouse cultivation consumes a great deal of energy in Finland, and in colder periods, the greenhouses largely use external energy for heating. Lately, the availability and price of energy have been hot topics, and they are steering development in a new direction. It should be noted that over the course of a year, a Finnish greenhouse collects more radiation energy from the sun than it needs for heating.
Project Engineer Arttu Lammensalo from Novarbo Oy believes that the greenhouses of the future could be self-sufficient in terms of energy if we figure out how to store the collected energy for colder periods in a financially viable way.
“Technology is always improving with new innovations being created. In a few years, the world will look different in this regard as well,” says Lammensalo.
In future, greenhouses have the potential to become energy producers. Greenhouses can feed energy into the district heating network, especially in the summer, and their heat energy could be used to heat up the domestic water of other properties in the same district heating circuit, for example.