Small towns in the Midwest are finding it difficult to expand renewable energy.
The loss of prime agricultural land is creating great economic difficulties for these types of communities.
However, the Village of Monroeville in northern Ohio has shown there is another way.
They have used their public water infrastructure, specifically the drinking water reservoir. It serves as the site for a very large 9,222 floating solar panel system.
This unique approach to developing utility-scale solar allows the town to increase their renewable energy output by over 100%. It also preserves the value of many acres of productive farmland.
A drinking water reservoir becomes a 6-megawatt solar platform
Development of utility-scale solar projects has historically been limited due to a need for a large area of contiguous land.
These parcels typically do not exist close to urbanized areas, resulting in higher acquisition costs.
In order to avoid all of these issues, the Village of Monroeville decided to utilize an existing municipal asset. They chose the drinking water reservoir as opposed to purchasing dry land.
D3Energy worked with village officials to engineer and construct the multi-island floating solar array above the reservoir.
The reservoir features a maximum depth of about 11 feet.
The construction of this project was made possible through bank anchoring systems and ballast weights.
Both were utilized in conjunction with high-density polyethylene pontoons that provide flotation and stability for the entire array.
These new technologies allowed engineers to deploy a 6-megawatt solar system across the water. This resulted in roughly 30 acres of productive farmland being preserved for current and future generations of farmers.
Overcoming the engineering challenges of open-water solar
Traditional ground-mounted solar arrays are constructed by installing heavy metal structures into the ground. These structures support the weight of the solar panels.
Artificial municipal drinking water reservoirs lack structural rigidity at grade level. Because of this, standard foundation pillar designs cannot be employed.
The total area for the Monroeville system is approximately 12 acres of water distributed across three separate floating island areas.
It would be impossible to install metal pilings into the clay bottom of the reservoir. Doing so would breach protective liner membranes and disrupt water storage functions.
Innovative anchoring systems and operational maintenance
Engineers, therefore, developed an alternative solution to overcome this site-specific challenge as opposed to using bed pilings, anchoring the array to shore-based point anchors.
Localized buoyancy was provided in each panel module through high-density polyethylene pontoons that did not penetrate the reservoir liner.
This allowed the array to withstand extreme weather conditions.
The pontoon design provided flexibility for water volume changes experienced seasonally due to varying levels of rainfall.
Advanced string inverters transmit the generated solar power efficiently back into the municipal electric grid distribution system.
Maintenance personnel access the floating solar array via boat. They perform routine work including inspecting the system, checking water levels, and testing the electrical equipment.
D3Energy has completed major drinking water reservoir solar installations in Ohio, including Monroeville and Del-Co Water.
Turning drinking water reservoirs into clean energy platforms
Installing solar panels on drinking water storage facilities provides benefits beyond basic electricity generation.
Covering 12 acres of open water with dense photovoltaic modules shields the reservoir from direct sunlight exposure.
Reducing surface evaporation conserves vital municipal water reserves during extended droughts and low precipitation periods.
Blocking solar radiation from penetrating the water column may help reduce algae growth under certain conditions. Changes in water quality may influence treatment requirements, although site-specific monitoring would be needed to determine any effects at the Monroeville reservoir.
Operating at lower temperatures than land-based systems allows these floating arrays to minimize heat-induced power losses and maximize daily electricity generation.
Municipalities looking out upon their existing public water storage assets see a high-value platform. This platform is capable of supporting their community needs while protecting their surrounding environment.
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