Opinion piece – Geothermal is ready, but is Denmark ready for development?

Winter view in Copenhagen, Denmark (source: flickr/ Kristoffer Trolle, creative commons)

Alexander Richter 21 Jun 2020

In an opinion article in Danish publication, Ingenioren, Susanne Poulsen, Technical Director at AP Moller Holding Geothermal, raises the question if Denmark is ready for geothermal development?

Danish utility companies are leaders in collective supply, including district heating, clean drinking water and green electricity. Danish architects and engineers are leaders in urban planning. Danish geologists and engineers are leaders in environmental technology, including subsurface mapping, groundwater modelling and drinking water protection.

Danish engineers, chemists, physicists, and mathematicians are leaders in pump and heat pump technology, process chemistry, filtration, well technology and digitalization. And finally, in Denmark we are world champions in collaborating and integrating technology to create green change that can be exported and deployed on a large scale.

In other words, in Denmark we both have the competences and the infrastructure to build Europe’s largest geothermal plant. So shouldn’t we just get started.

We hold our breath these weeks as politicians embark on crucial negotiations regarding the regulatory framework for geothermal energy. Under our feet lies a great inexhaustible source of renewable energy, which can be harvested without CO2 emissions and particle pollution. It is a source of green heat, but also of green jobs, and it is an opportunity for Denmark to make an even greater green difference in the world. Let us seize the moment now.

We are ready with a ready-made project that several Danish companies, universities, authorities, and utility companies have contributed to the development of. We have in fact already started. We have made an early strategic environmental assessment, which is our suggestion for responsible development and operation of geothermal energy.

However, the regulatory framework for geothermal energy production in Denmark have to be resolved and this is urgent. As early as 2021, we can be ready to drill the first exploration wells, collect static and dynamic subsurface data, analyze water samples, and thus map the quality of the resource. All the data we collect will be used – in close collaboration with the utility company – to design the large-scale plant, which offers the lowest possible heating price and the highest security of supply. A large-scale plant requires a wide collaboration between many qualified suppliers. Wells, heat pumps, heat exchangers, filters, electronics, control systems, etc. are widely tendered. About 80 percent of the subcontracts will be tendered, so that we ensure competitive prices.

By 2023, we may be ready to start building the large-scale plant itself. The system consists of a series of small decentralized plants that each are connected to the district heating network. All the technology used in a geothermal plant is well tested and well known. But we have re-designed the way to build geothermal plants, and we are in the process of patenting that.

What is new is that the system is modularized, standardized and scalable. In practice, this means that the plants can be built off-site at yards or at suppliers and then be installed quickly. This also means that as a citizen you do not have to be a neighbor to a building site for a long time. Our construction method also means that we will not oversize the plants.

It is crucial for us to take good care of our neighbors and the surrounding environment. A decentralized plant has a foot print similar to the penalty area of a football field, and it can be partially buried – in a bunker solution – to minimize noise disturbance. We work with talented architects who involve the local community in the visual and functional integration of this type of small technical installations in the urban space. Danish drinking water is our most precious natural resource. Therefore, we use certified drinking water well drillers as we pass the groundwater layers, and we will install an extra casing as an additional barrier to the groundwater

By 2024, we may be ready to switch on the first plant. This means 30 years of stable production of green heat at a plant that can be supplied by 100 percent wind turbine power. A large-scale geothermal plant will typically produce between 70 and 150 MW of heat for the base- and intermediate load in the district heating network. Geothermal is thus one of several types of, hopefully green, heat production plants in a big city. It is the district heating company that plans and decides when and how they use the heat from the geothermal plant, so that they get the cheapest possible heat for the citizens.

There are a number of classic challenges in geothermal installations – for example, corrosion, precipitation of salts and clogging of wells. These are some of the themes that interest us the most because there are still scientific developments to be made in smart water technology. We are in dialogue with Danish and foreign universities about the water treatment of the future, just as we are in dialogue with subcontractors on filter technology and oxygen-proof solutions for process equipment.

90 percent of a geothermal plant is in the underground. It was ‘built’ 200 million years ago, and no drawings and user manuals are available. Our geologists, petrophysicists and engineers must make  the manuals themselves. Our team of engineers and geologists have been training for this since each of us started in the oil industry more than 20 years ago. And we experience an overwhelming support from many Danish companies and universities.

In other words, we are many who are ready in the starting blocks, waiting for the regulatory framework for geothermal energy to be ready, so that we can start delivering green heat to Denmark. And afterwards to the world.

Attention: We since updated the text to clean out some “lost in translation” elements. Thanks to our our friends at APM for the quick help.