With help from the municipality of Pijnacker-Nootdorp, BNG Bank, Rabobank, Meewind, and Nationaal Groenfonds, Ammerlaan Geothermie BV has restored a geothermal project dating from 2010. This will save 22,250 tonnes of CO2 emissions annually. It is the first project in the Netherlands to supply geothermal energy on a large scale to both homes and greenhouse growers.
In 2010, pot plant nursery Ammerlaan The Green Innovator was the first horticultural company in the Netherlands to use geothermal energy at its own expense and risk to make its cultivation and business more sustainable. Thanks to geothermal energy, the green pot plants grow in an almost CO2-neutral way. Because the capacity of the source was considerably greater than the heating requirements of Ammerlaan's greenhouses, a large number of additional heat consumers were gradually connected to Ammerlaan's heating network after 2010. Further expansion of the number of consumers is also expected in the coming years.
In the summer of 2017, a defect arose in one of the two kilometre-long steel pipes used to pump up the geothermal energy. In order to get the geothermal heat source up and running again, the municipality of Pijnacker-Nootdorp, among others, felt compelled to support the restoration of the project. Aldermen Frank van Kuppeveld and Peter Hennevanger of the municipality of Pijnacker-Nootdorp: ‘Based on our ambition to generate 15% of the total heat demand in the municipality of Pijnacker-Nootdorp sustainably by 2020, we felt that this project should not be lost, and the municipality has also taken up the challenge to make the project a success after all.’ The municipality's ambition has thus been more than achieved. Not only Ammerlaan benefits from the annual yield of 110 MWh of energy. Twenty-four other greenhouse horticulture companies, the local swimming pool, the sports hall, a school and more than 500 flats are also heated with this energy. The surrounding greenhouse growers, who are constantly looking for ways to make their businesses more sustainable and energy-efficient, are also delighted with this particularly sustainable form of energy. This makes it the first project in the Netherlands where geothermal energy is supplied on a large scale to both the built environment (homes) and greenhouse growers. The entire geothermal system saves 12,500,000 m3 of gas per year, reducing CO2 emissions by 22,250 tonnes annually.
Due to the unusual risk profile and financing requirements, several parties are involved in the financing. Thanks to the collaboration between the Ammerlaan horticultural company, the Municipality of Pijnacker-Nootdorp, Rabobank, BNG Bank, sustainable investment institution Meewind and the Nationaal Groenfonds, the financial risks were spread and the project could be restored. The intention is that the Municipality of Pijnacker-Nootdorp will withdraw as a financier in the foreseeable future.
The major advantage of geothermal energy is that it is a virtually infinite source of clean energy. At Ammerlaan, hot water at a temperature of over 78 degrees Celsius is pumped up from a depth of approximately 2.3 kilometres in a completely closed system. After heat has been extracted, the water is pumped back into the earth at a temperature of 35 degrees Celsius via the same closed system (where it is then reheated to 78 degrees). At the surface, the energy is extracted from the groundwater via heat exchangers and transferred to another closed system, namely the heat distribution network that transports the heat to consumers.