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How the geothermal sector gets off the ground in the Netherlands

Mapping heat demand vs. knowledge of the subsurface (source: TNO/ EBN via energiepodium.nl)
Alexander Richter 26 Jul 2019

A detailed article by EnergiePodium.nl shares details how the geothermal energy sector in the Netherlands is getting off the ground .. to a rather good start.

An initiative by gas trading company GasTerra in the Netherlands, energiepodium.nl has published a rather interesting article on geothermal energy in the Netherlands.

The article describes how, there are today around twenty geothermal installations at work in the Netherlands, almost all in greenhouse horticulture. But with the ambition of the government for the construction of heating networks for heating homes with geothermal energy, hundreds of those wells will have to be added in the coming decades.

The article provides details on the approach on how the sector in the country is starting up.

In conjunction with the European Geothermal Energy Congress that took place in The Hague in June 2019, a field trip led to a drilling rig on a project site of the new TNO innovation center for the geothermal sector. “With this full-scale research facility you can directly test how new things work in the field and save so much time and money,” explains project leader Gert-Jan Heerens to the group of geothermal heat specialists who visit the Well Innovation and Heat Open Innovation Center as a part of this field trip.

The test center, so Heerens, includes installations for carrying out all kinds of mechanical and hydraulic tests under high pressure and temperature. “It’s all about sizing-up here”, he assures his international visitors. Especially for smaller companies that want to test a new invention on a real drilling floor or in the subsurface, the new research center is a solution, he explains. “It bridges a gap for those entrepreneurs. Normally they do not have access to a real drilling rig for doing such tests, because owners are afraid that this will hinder their own operation. ”

Heerens compares geothermal energy in the Netherlands with offshore wind energy when that sector was in its infancy some ten years ago: its costs must be reduced by thirty or forty percent if geothermal energy in the built environment is to become a commercial alternative to fossil heat. New materials and adapted drilling concepts and well structures must also make the extraction of geothermal heat more suitable for use in residential areas. “It must be more compact, efficient and with less nuisance to the environment, but safe.” As examples of innovations that the sector is working on, he mentions plastic drill pipes instead of steel, smaller drill rigs and sensors that make the drilling process more predictable and reduce the risk of underground leaks.

Frank Schoof, chairman of the Geothermal Platform, which brings together all parties involved in geothermal energy, endorses the importance of innovation: “A lot has already been achieved by geothermal energy companies, but there is still much room for improvement in geothermal energy in the Netherlands and cheaper. So this research center is definitely an asset. ”But politics must also support geothermal heat, he emphasizes. Financially, that support is now there, he notes, referring also to the geothermal letter that Minister Wiebes sent to the House of Representatives in March. “But politicians still have to create more support locally and convince residents that compared to alternatives, the risks of geothermal heat are acceptable. And above all: that heating networks in certain neighborhoods are cheaper than individual solutions. ”

In 2050, roughly half of the homes in the country will be connected to district heating and perhaps half of the heat will come into those geothermal networks, Schoof notes, partly on the basis of the Climate Agreement agreed at the end of June. To achieve that transition, all municipalities must have drawn up a heat plan per neighborhood in 2021. Energie Beheer Nederland (EBN), which receives a legal task on behalf of the state with the letter from Wiebes to the House of Representatives for the development of geothermal heat, will be conducting seismic research for a large part of the country together with TNO. Under the name SCAN (Seismic Campaign for Geothermal Energy in the Netherlands), it is determined where the Dutch subsurface may be suitable for geothermal heat development. Because in areas where oil and gas have never been drilled, the map of our country still shows a lot of white spots. “Eighty percent of the heat demand in the Netherlands is in areas with low or no knowledge of the subsurface,” said Geothermal Energy Master Plan that Platform Geothermal Energy issued last year together with EBN, Stichting Warmtenetwerk and DAGO, the branch organization for geothermal operators in the Netherlands (see map, shared above).

Schoof explains that, due to the large number of customers required, heat networks are only an option for densely built-up areas. Perhaps with the exception of historic inner cities, because the construction of thick heat pipes requires a lot of demolition and excavation work there. According to him, therefore, homes from 1920-30 in more recent districts are particularly suitable for urban areas. Even for some zero-meter new-build homes, district heating can be an option: “In addition to the heat that they generate themselves, those homes certainly also need extra molecules in a severe winter, for example from a heat network with geothermal heat as a base load.”

Leyweg Geothermal Energy (HAL) in The Hague is such a geothermal project as basic heat supply in an existing heat network. The project in The Hague Southwest, which is a relaunch of a geothermal doublet (a production and an injection well) drilled in 2010, is indicated by Schoof, expected to be ‘steaming’ at the beginning of next year. For the realization of this first inner-city geothermal heat plant in The Hague and the Netherlands, HAL works closely with the municipality, Eneco and Uniper (formerly E.ON). With the high potential of geothermal energy in South Holland, the intention is that the Hofstad will have at least ten more geothermal power plants in the coming years.

Other geothermal heat projects in urban areas that are in the starting blocks are the Lean research project (Low cost Exploration And deriskiNg or geothermal plays) of Warmtebron Utrecht and the Delft Geothermal Project (DAP, an initiative of TU Delft). But other cities in the country are also breeding plans for district heating powered by geothermal heat, such as Amsterdam, Rotterdam and Nijmegen. For the Lean research project, test drilling in the area between Utrecht-Zuid and Nieuwegein is planned for the second half of 2020. The long pre-drilling phase has to do with, among other things, the geological subsurface of the Domstad. And Lean anticipates the seismic investigation of EBN / TNO. The initiators must therefore first make an analysis themselves of scarce existing data from that subsurface.

“Only after the test drilling do we really know whether there is potential for geothermal heat for the Utrecht heat network,” adds Jan Brandts, responsible for geothermal energy at Engie in the Netherlands. The energy and technology company is one of Lean’s partners, together with TNO, Eneco (heat customer), Utrecht University and Huisman Geo, among others, which will also carry out the drilling. Depending on the size of the hot water reservoir that is expected to be found three kilometers deep, there will be a maximum of six doubles in the area (see box). In addition to Lean, Warmtebron Utrecht also has a research project: Gold, which is investigating the possibility of ultra-deep geothermal heat for the area at Utrecht Science Park and the Rijnsweerd office park.

EBN is also a partner of Lean and DAP on a voluntary basis, with a financial interest of forty percent in both consortia. By allowing the government-owned company to participate risk-bearingly in geothermal heat projects, Wiebes wants to make financing such projects attractive to banks and institutional investors. The minister set aside fifty million euros for participation in projects by the public company for a period of five years. The amendment of the Mining Act that is needed to regulate EBN’s geothermal energy roll is due mid-next year, expects Eveline Rosendaal, geothermal program manager at EBN.

The Netherlands now has around twenty geothermal doubles, almost all in greenhouse horticulture. Schoof of Platform Geothermie indicates that in order to achieve the ambition of the cabinet, it must quickly become more, 175 in 2030 and several hundred in 2050. If SCAN has better charted the subsurface of the country, faster the right choices are made. In that context too, TNO has carried out an international study for EBN into the relationship between geothermal heat projects and seismicity. This study shows that the structure of the Dutch subsurface is particularly suitable for extracting geothermal heat, Rosendaal points out. “Safe and responsible extraction of geothermal heat is possible in many places in the Netherlands. Naturally, we carry out further research into potential risks for each project. Safety is a priority here. ”The study is now at the Ministry of Economic Affairs, where it will be taken into account in future policy choices. Rosendaal emphasizes that the consideration of whether or not to drill is not up to EBN but to the ministry. ”EBN is committed to explaining well together with the sector what exactly geothermal heat extraction entails. Because unknown makes unloved. ”

“Geothermal heat extraction is mining and that is inherently uncertain. But you should not overdo that uncertainty, “Schoof agrees. According to him, it would be good if there was a damage fund, for overcoming resistance of homeowners to geothermal heat. “The chance that geothermal energy causes damage to homes is extremely small. But suppose it happens once, it is good that homeowners know that they can turn to such a fund for compensation. Such a scheme is now being considered within the sector. ”

Schoof also expects SCAN to extend to areas where water extraction companies do not want drilling for geothermal energy due to the risk of groundwater pollution. “Of course drilling is not allowed in water catchment areas. That is and remains the case. The fact that drilling is also not allowed in the protection zones around these areas remains the same. But then there are even larger areas where water may be extracted in the future. Consultations are currently taking place in various provinces about these areas on how you can designate them so that future water extraction can merge in a good and safe way with geothermal locations. as well design, reducing the chance of leakage and improving monitoring.

With the increased attention for geothermal energy, new materials and techniques are in the spotlight. An example of this is well casing, casing in professional jargon. This is not of steel as usual, but of composite material. At the Huisman Geo stand at the European Geothermal Congress in The Hague, such a plastic pipe sleeve attracted a lot of attention. The expectations of the use of plastic casing when drilling for (salt) hot water in the deep subsurface are therefore high. Corrosion-free, with less scaling (mineral precipitation) and lighter than steel – which allows working with smaller faucets and more compact drilling rigs – they result in a substantial saving on operational and investment costs. “A very interesting technology for the sector,” concludes Jan Brandts van Engie. Nevertheless, he does not expect that it will already be used during the test drilling for the Lean research project, to which Huisman and Engie are partners. Because plastic casings still have to prove themselves in Dutch geothermal energy. “There are already enough risks associated with such a first drilling, regardless of the technological challenges. But it could well be that we will use them later in the project. ”

Brandts lists the three innovations that are used in the Lean test drilling:

  • seismic reprocessing (“look at the computational power of computers from now-old seismic systems of TNO through sharper glasses for more data”)
  • portofolio approach (geothermal heat projects do not develop as standalone but grouped, so that they can ‘learn’ from each other optimally, as advocated in the EBN / TNO report ‘The whole is greater than the sum of its parts’
  • innovative combination of drilling technologies from the oil and gas sector

At Huisman Geo, Remco van Ee, responsible for business and technology development, further explains the Lean test drilling as a process of controlled drilling (Rotary Steerable System – RSS) in combination with ‘casing drilling’ (the drill pipe is also well formwork), and pressure-controlled drilling (managed pressured drilling – MPD). “All of them are proven techniques from the oil and gas sector that we have made suitable and affordable about geothermal energy.”

Casing drilling can also be done in the future with plastic casing pipes, Van Ee predicts. He mentions a multi-walled well construction with a conventional steel formwork and a composite inner pipe as the first application of plastic well casing. “In addition to the advantages of no corrosion and less scaling, such a tube-in-a-tube offers double-walled protection, which is certainly an additional advantage in drinking water areas.” The aim of Huisman Geo is to use all these different techniques – casing drilling, RSS , MPD and composite casing – to be brought together on a drilling platform specifically for geothermal heat. Van Ee expects that this highly automated (“fewer males on the drilling floor”) and also easy-to-move dedicated geothermal rig will be operational in about three years.

In addition to Lean, Warmtebron investigates Utrecht with various parties, such as Utrecht University and UMC Utrecht tapping heat at a depth of four to ten kilometers. Brandts van Engie, which is also part of this research project Gold, expects that this will not be completed until 2022-23 at the earliest. “For ultra deep geothermal energy (UDG), much more needs to be found, not just about the seismic situation. Tapping into such depths also requires a completely different drill design. Because you will have to deal with other rocks than we are used to with geothermal energy in the Netherlands. ”The seismic survey for this project uses SCAN from EBN. Because with this program the possibilities of UDG are also mapped out for the whole of the Netherlands, in the context of the Green Deal Ultra Deep Geothermal Energy.

Source: Energie Podium