Pioneering greenhouse heating with a 2 MW CO₂ heat pump
In the Dutch region of Noord Brabant, Kwekerij Aarts has taken a bold step towards sustainable horticulture by installing a 2 MW air to water heat pump to support a new 3.6 hectare greenhouse
The system is thought to be one of the largest of its kind within the greenhouse sector, marking a significant shift in how growers approach energy use.
Owner Rens Aarts explored several options before settling on the heat pump. Grid limitations ruled out combined heat and power as the main solution, and although a geothermal permit was secured, the final choice leaned towards a more flexible and forward thinking system. The unit, running on CO₂ as a natural refrigerant, has been in operation since early this year.
"We are willing to pioneer," says Rens Aarts. "We knew we were taking a path where no one had gone before."
The family business has always embraced innovation. With 9.6 hectares already in use for cucumbers and autumn tomatoes, the expansion demanded a heating capacity far beyond standard systems. Careful planning ensured the greenhouse was well insulated and supported by a low temperature heating network designed for efficiency.
"We preferred a natural refrigerant and chose CO₂. Our first thought was that if a leak were to occur and refrigerant entered the greenhouse, CO₂ would not be harmful to the plants," Aarts explains.
The system operates best with a steady return temperature of 30°C, allowing it to deliver flexible output levels. Alongside the heat pump, solar panels and an additional CHP unit provide energy balance and backup. Smart software manages the entire setup, ensuring consistent performance despite fluctuations in weather and electricity supply.
"We can control three heating networks independently, or extend a network when we need a lower return temperature," Aarts explains.
The project has not been without challenges, particularly in maintaining stable conditions for the heat pump. However, interest from other growers is already growing.
"Make sure you have this properly calculated under winter conditions," Aarts advises colleagues. "That is when it really matters."
With plans for future expansion, Kwekerij Aarts is setting a clear example of how innovation and sustainability can go hand in hand.
