A Dutch consortium recently tested four different PV system configurations along the water in the Netherlands. The country has about 17,000 kilometers of dams, and preliminary research has shown that they offer the potential for 11 GW of solar power.
“We see that solar power on coated piles is currently the most promising,” TNO researcher Maarten Dörenkämper said. pv magazine. “With nuro it is more challenging, this requires further research to find specific suitable configurations for grass dams.”
Dams and their surfaces represent an unused opportunity to build solar power plants in sparsely populated terrain. The Netherlands has about 17,000 kilometers of dams, and preliminary research has shown that they offer the potential for 11 GW of solar PV systems without agricultural land.
In addition to dams acting as a liquid, dams in the Netherlands are often used for recreational purposes, especially for cycling. Over time, they have started to be seen as cultural-historical landscape elements.
“In addition to technical feasibility, it is very important to find out exactly where these systems can be placed. We have studied and identified with GIS analysis the most promising places for these systems based on social acceptance factors,” Dörenkämper added. “Dams located in a more industrial environment are ‘low-hanging fruit’ in terms of social acceptance.”
The scientists said in their report that they have tested four different pilot-scale photovoltaic systems. The first was a 39.5 kW system with a fixed mounting structure on the lawn. The “TNO-Eurorail” system is installed on the lawn and has a fastening structure on small piles installed in the ground at a limited depth so as not to cause major damage to the dams.
The solar panels are placed at a height of 80 cm to 1 meter, allowing the sheep to graze under the panels. The DC cabling between the installation structure is buried without a pipe, because the use of casing pipes on top of the dam can cause the formation of a tunnel.
Another installation, developed by Dutch technical service provider Delmeco, is a 6.8kW solar power system that replaces the grass with a concrete element containing each panel. The weight of the components and the gluing of the solar panels also prevent theft and make the system vandal-resistant.
The third demonstration, built by Dutch developer Soltronergy, is a 5.4 kW installation with stainless steel cables mounted on steel legs between concrete ballast blocks. It has lightweight plastic PV panels placed vertically at a height of 80 cm and able to rotate slightly in the direction of the wind, the researchers said.
The fourth project, developed by Dutch landfill specialist Afvalzorg, is a 20kW system embedded in Solarbase, a hardening material for solar panel dams. The system is made of certified recycled raw materials and replaces the grass cover of the dam. The DC cabling is largely inaccessible and hidden under the panels, while the inverter is placed at the base of the dam.
The researchers found that solar PV systems that are installed and fit well with current dam construction practice may be technically and economically feasible without much additional research.
“Many grass cover shading systems have not yet proven suitable for water safety,” they said. “We have studied different layout configurations of solar panels that allow different levels of radiation to reach the grass surface. However, since grass cover degradation is a slow process, we cannot achieve an optimal and absolutely safe configuration at this stage. We also found that the systems work well from an electrical performance point of view, and no direct erosion formation has been observed.”
The Dutch authorities are having trouble finding land on which to place large solar power plants due to the scarcity of land. In recent years, research institutes and private companies have attempted to prove the feasibility of solar projects on non-agricultural land, including rooftops, road noise barriers, onshore and offshore water bodies, and bike paths.