Work on boring a four-kilometer-deep shaft below the Westland greenhouse growing region near The Hague has begun, the Financieele Dagblad  reported on Thursday.

The pilot Trias Westland boring tower will be operative in September but it will be December before the first geothermal heat will be pumped up to serve the vast flower and vegetable growing greenhouses in the area. The heat comes in the form of water heated to 140 degrees.

The €50m pilot project will be twice the size of other geothermal heating plants in the Netherlands. Trias Westland director Marco van Soerland said geothermal projects are much more expensive than solar panels as a heat source.

It remains uncertain whether the project will succeed, Van Soerland said. The Westland auction as well as 43 growers have committed to buying the geothermal heat which, if succesfull, is expected to provide between 10% and 20% of annual heating needs.

Van Soerland said that green energy is increasingly important. ‘Growers, whether they be in flowers or vegetables, have clients who demand sustainable products.’ The projected lifetime of a geothermal shaft is 15 years.