There are some 10,000 kilometers of quays in the Netherlands, and many of them need to be renovated in the near future. With an energy dam wall you can easily link that task to sustainability.
The principle of the energy dam wall is actually simple. There is piping behind the steel sheet piling, which can be connected in series to the piping in other sheet piling. The piping contains a mixture of glycol and water. The sheet piling then acts as a heat exchanger, allowing the mixture to be heated several degrees by the water. The heated mixture can then be converted into high-quality heat with a heat pump.
From idea to design
The idea for the energy dam wall originated ten years ago with dam wall supplier Gooimeer BV, explains Jasper van Eijs, energy technology consultant at Energiedamwand Nederland. "At first, by the way, they were thinking about soil energy," he says. "But you get nine times more energy from water than from soil." Gooimeer then contacted CRUX Engineering, which provided the design and energy calculations. In the design, the piping goes across the entire dam wall, so that not only is heat absorbed from the water, but also additional power from the soil.
In 2018, the two companies founded Energy Dam Wall Netherlands, bringing focus to the development of the energy dam wall. "In the first years, the focus was on research and development, which we did in cooperation with a number of universities. As a result, validation is now down to the last detail. Reliability and measurability are very important, because there is always cold feet among clients when you come up with something new."
Apart from the pilots, several parties wanted to deploy the Energy Dam Wall right away. "This allowed us to focus on project development quite early on," he says.
Linking replacement to energy solution
"There is a huge opportunity," says Van Eijs. "There are thousands of kilometers of quays in the Netherlands. Large parts of them need to be renewed in the short term. We can now link that replacement of the infrastructure to a sustainable energy solution. That way we kill two birds with one change."
By the way, the quay does not always have to be renewed. Existing sheet piling can be transformed into energy sheet piling with the addition of a heat exchanger in the sheet piling greenhouse. In doing so, the piping goes a little shallower than in the case of prefabricated energy sheet piling, so no additional power is available from the ground.
Sufficient surface area
The deployment of the energy dam wall does require a match between the existing infrastructure and the heat demand. In other words, there must be enough quay to generate heat. "In terms of power, it's purely about the surface area of the dam wall in the water, which is the most important parameter," says Van Eijs. "The deeper the water and the wider the quay, the more power is available. You just have to have flowing water, with a water depth of at least one meter."
Because you don't take the water and discharge it back in, as with open aquathermy, the ecological impact on the waterway is minimal. "At half a meter from the sheet piling, there is already no measurable temperature difference," Van Eijs states.
Focus on large-scale
The energy dam wall can be used in all kinds of projects. "The energy dam wall is in place anywhere there are sheet pile walls and a sustainability challenge. It is cheaper than a soil source and the COP of aquathermy and soil is much higher than that of air. As a result, much less electricity is needed to generate the same heat."
If your house is along a river or canal, Van Eijs says there are already possibilities. "It's interesting for smaller and larger capacities. With three pieces of sheet piling you do a house. But our vision lies in large-scale projects, where the infra goes upside down anyway." This is well illustrated by the project in Cuxhaven in Germany. "There, over 1,200 meters of sheet piling are being installed to heat a house or 14 or 1,500. That produces a source power of more than 2 MW!" From the sheet piling, installers lay a low-temperature network that runs to the homes. Each of those homes, in turn, will have its own heat pump that will provide the high-quality heat needed.
In the Netherlands, the energy dam wall has already been installed in the Nobelhorst neighborhood in Almere, the Compagniehaven in Enkhuizen and Molenterrein de Otter in Amsterdam, among others.
Also read: A look behind the scenes of a pioneering market leader: 'Everyone benefits from aquathermy'
