Greener greenhouses promise more energy-efficient growing power

In the province of Almería in southeastern Spain, farmers grow an estimated 2.5 to 3.5 million tonnes of fruit and vegetables every year in what has become known as Almeria's sea of greenhouses. In this region, greenhouses stretch as far as the eye can see, covering an area of over 40 000 hectares (400 square kilometres).

It's partly thanks to this production that consumers across the continent can enjoy foods such as cucumbers, tomatoes and melons throughout the year. But there's a catch, these greenhouses aren't always very sustainable in terms or energy or water use.

Serena Danesi is a research associate at the Institute of Energy Systems and Fluid Engineering (IEFE) in Zurich, Switzerland. She specialises in thermal engineering and heat recovery and, over the past four years, has been leading the TheGreefa project that received funding from the EU to develop a new, more energy-efficient and environment-friendly system for controlling both temperature and humidity in greenhouses.

If Europe wants to meet its climate targets, and set the standard for sustainable food production – a goal set out in the EU's Farm to Fork strategy adopted in 2020 – then improving the sustainability of greenhouse farming will be a key concern.

'If we want to eat cucumbers, tomatoes and watermelons all year round, we need to be aware that their cultivation consumes a lot of energy and water,' said Danesi.

Climate control
Changes in climate conditions and a need to have more control over the growing environment of crops have led to a rapid expansion of commercial greenhouse cultivation across Europe.

It was estimated, in 2018, that Europe had some 210 000 hectares (2 100 square kilometres) of greenhouses, with particularly high concentrations in Spain (70 000 ha), Italy (42 800 ha), France, the Netherlands, and in Central and Eastern Europe.

The energy needs of greenhouses differ, however, depending on their location. TheGreefa brings together researchers from Italy, France, Germany, Spain, Switzerland, Poland and Tunisia to investigate how their proposed system performs in different climate zones.