Using Quarry Lakes as Solar Power Sites
A white paper by Nexentury shows how floating solar power systems and battery storage on artificial bodies of water can contribute to self-sufficiency and lower energy costs.
September 3, 2026
Source: E & M powernews
In a new white paper, Nexentury shows how raw materials and industrial companies can use dredged lakes for floating PV and battery storage. This could alleviate pressure on scarce land resources.
Nexentury GmbH, based in Starnberg, has published a white paper on the use of dredged lakes to supply energy to raw materials and industrial companies. Titled “Energy Sovereignty – Made in Germany,” the white paper describes how companies can harness their own bodies of water with floating photovoltaic systems (floating PV) and battery storage to meet their own energy needs.
Nexentury develops and operates floating PV systems and specializes in the use of water bodies for electricity generation. In the white paper, the company outlines the technical, regulatory, and economic aspects of such projects. According to Nexentury, these include, among other things, the requirements under the Renewable Energy Sources Act (EEG) 2023 and Solar Package I, as well as issues related to electricity costs, return on investment, and payback periods.
6,000 Artificial Water Bodies
Nexentury cites the more than 6,000 artificial lakes in Germany as a starting point for raw materials and industrial companies. According to the Fraunhofer Institute for Solar Energy Systems ISE, these bodies of water could offer a potential of approximately 15,000 MW of installed photovoltaic capacity. Some of these areas consist of quarry lakes that are operated or owned by gravel and raw materials companies themselves. Utilizing such areas could help avoid land-use conflicts with other onshore applications.
The white paper uses a real-world example to demonstrate how such a system can be evaluated economically. Nexentury cites the floating PV system on Philippsee Lake in Bad Schönborn, which has been in operation since July 2024. According to the company, it operates a system there with a capacity of approximately 15 MW. The quarry lake is owned by Philipp & Co. KG, which operates a gravel plant there. The gravel plant uses part of the electricity generated to power its own operations.
The Philippsee Example
Philippsee is located about 20 kilometers south of Heidelberg (Baden-Württemberg) and covers a water area of more than 60 hectares. According to Nexentury, the floating PV plant occupies approximately 8.2 hectares of this area. The plant consists of 27,160 solar modules. The modules are mounted on a floating substructure made of HDPE pontoons and connected to form what are known as “module boats.” The electrical equipment is also designed for operation on and near bodies of water.
The modules are arranged in an east-west orientation. Nexentury states that it has increased the spacing between the modules to allow for greater light transmission. The floating structures use a gable arrangement designed to improve aeration of the water’s surface. To protect the shoreline, the system was anchored to the lake bed.
According to Nexentury, the ownership structure of Philippsee and the existing excavation rights have facilitated the project’s development. Philipp & Co. KG reportedly holds the property rights to the lake as well as rights to expand gravel extraction operations for another 25 to 30 years. This timeframe roughly corresponds to the average service life of a photovoltaic system. In addition, according to Nexentury, electrical infrastructure was already in place due to the adjacent gravel plant.
Storage as a Complement
In addition to floating PV, the white paper considers battery storage as another key component. It can help ensure more flexible use of the solar power generated over time. Nexentury also presents various investment models that enable companies to align their energy supply more closely with their own generation.
The company cites volatile energy prices, geopolitical supply risks, and increasing requirements for sustainability and reporting obligations, among other factors, as reasons for greater self-sufficiency. The white paper is intended to help companies assess the technical potential of their water bodies, as well as electricity costs, economic viability, and potential permitting processes, prior to project development.
The white paper on PV on dredged lakes is available online.
Author: Susanne Harmsen