28 July 2025

As the global demand for clean energy intensifies, floating solar power systems—also known as floatovoltaics—are emerging as a transformative solution. By utilizing water surfaces for solar energy generation, these systems offer a sustainable approach to renewable energy, especially in regions with limited land availability.

The Basics of Floatovoltaics

Floating solar power systems involve mounting photovoltaic (PV) panels on buoyant platforms that float on bodies of water such as lakes, reservoirs, industrial retention ponds, and even calm sea surfaces. These structures are anchored to the bottom or tethered to surrounding shorelines, allowing them to remain stable in varying weather conditions.

This design is not only a clever use of space but also brings significant performance advantages. The water beneath the solar arrays has a cooling effect on the panels, which can increase their efficiency compared to land-based systems, particularly in hot climates. Solar panels typically lose efficiency as they heat up, but the ambient temperature of the water can keep them cooler, especially during summer peaks when solar power is most needed.

Moreover, the panels themselves help shade the water, reducing evaporation—an increasingly important benefit in regions facing water scarcity due to climate change. This dual functionality of energy generation and water conservation enhances the overall environmental return of floatovoltaic systems.

Why Floating Solar Is Gaining Global Attention

The global solar energy market is rapidly expanding, but land use remains a challenge. In densely populated areas or regions with valuable agricultural land, large-scale solar farms can lead to competition for space. Floating solar provides a compelling alternative.

From Southeast Asia to Southern Europe and parts of Africa, governments and utility companies are now turning to floatovoltaics to expand their renewable energy mix without impacting existing land use. According to the World Bank, if just 1% of the world’s man-made reservoirs were covered with floating solar, it could generate as much electricity as all current global hydropower plants combined.

Rotterdam’s Kralingen Floating Solar Park: A Dutch Case Study

The Netherlands, a country defined by its relationship with water, faces unique constraints on land use due to its dense population, intensive agriculture, and nature conservation goals. That’s what makes the floating solar park in Kralingen, Rotterdam, such a compelling example.

Built on a drinking water reservoir operated by Evides Waterbedrijf, the Kralingen floating solar park shows how clean energy and clean water can coexist. The project is a collaboration between Evides, solar energy provider GroenLeven, and technical experts from the TU Delft and other research institutions. Its goals are twofold: to produce renewable energy and to rigorously monitor the environmental impact of doing so on a sensitive water ecosystem.

The solar park includes over 3,000 solar panels mounted on floating platforms and covers roughly one-third of the reservoir surface. It supplies electricity directly into the local grid, helping Rotterdam reduce its carbon footprint. But the most important feature of the Kralingen project is its holistic approach: every component was selected and tested to ensure that the panels don’t compromise the quality of drinking water or damage local biodiversity.

Evides emphasized the importance of continuous monitoring from the outset. Sensors track water temperature, algae growth, and other key quality metrics. Early data shows no negative impacts on water quality, while the shade from the panels actually helps reduce the growth of potentially harmful algae blooms—a common issue in shallow, nutrient-rich waters during warmer months.

A Blueprint for Public-Private Collaboration

The Kralingen solar park illustrates how multi-stakeholder collaboration can accelerate innovation. Municipal water utilities bring local infrastructure knowledge, renewable energy developers contribute engineering expertise, and universities conduct rigorous impact analysis. By coordinating their efforts, these parties were able to turn an underused reservoir into a productive, sustainable asset without compromising its primary function.

Environmental and Economic Benefits of Floating Solar

In addition to land conservation and improved panel performance, floating solar brings several other benefits:

• Reduced algae and eutrophication: By shading the water, floatovoltaics can limit light penetration, helping to control algal blooms, which are not only a nuisance but also a public health concern in reservoirs.
• Energy proximity: Floating solar parks can be built near water treatment plants or urban centers, reducing transmission losses and avoiding the need for new grid infrastructure.
• Dual-use optimization: Floatovoltaics allow for dual-use of space, especially important in countries like the Netherlands where every square meter counts.
• Reduced maintenance: Thanks to the cooling effect of water and minimal dust accumulation, floating panels often require less frequent cleaning than land-based systems in dry regions.

However, floating solar isn’t without challenges. Installation costs are typically higher due to the specialized equipment needed to float and anchor the panels. Corrosion and wear from constant exposure to water must also be managed, especially in saline or brackish environments. That said, as the technology matures, costs are expected to fall—just as they have for traditional solar PV.

The Road Ahead: Scaling Floating Solar in Europe

In the Netherlands alone, analysts estimate that over 6,000 hectares of artificial water surfaces—including sand mining pits, reservoirs, and canals—could be suitable for floating solar installations. The potential success of projects like the one in Kralingen could open the door for wider adoption of floating solar not just in the Netherlands, but across Europe. The European Union has set aggressive targets for renewable energy as part of its Green Deal and Fit for 55 legislative package. Floating solar can help meet these goals.