5 Hidden Drawbacks of Floating Solar Energy Systems [+ Cost Analysis]

Explore the five major drawbacks of floating solar energy, including increased costs and environmental concerns. Get a detailed cost breakdown of floating solar installations.

Introduction to Floating Solar:

Floating solar, also known as floating photovoltaic (FPV) or floatovoltaics, refers to solar power systems installed on water bodies like reservoirs, lakes, or oceans. Unlike traditional ground-mounted solar panels, these are placed on floating structures on the water's surface.

Interestingly, these floating panels not only generate renewable energy but also help in maintaining the cleanliness of freshwater reservoirs.

While floating solar technology is gaining popularity worldwide, it remains relatively rare in the United States. The first floating solar project in the U.S. was launched at Far Niente Winery in California.

Recently, pilot projects have started in the U.S. For instance, in 2023, Duke Energy initiated the construction of floating panels in a cooling pond in Florida. Duke Energy, one of the largest American utilities, with over 50,000 MW of energy capacity, aims to achieve net-zero carbon emissions from electricity by 2050. "It's an efficient use of space," says Don Keyes, a construction supervisor at Duke Energy. "There's no need for land or displacing crops. We're optimizing the resources we have. With the rapid growth of solar, it's crucial to find space for these installations."

Bifacial Solar Panels: Keyes also adopted an innovative approach by using bifacial panels instead of the conventional monofacial ones. While traditional panels capture sunlight on only one side, bifacial panels can absorb light from both sides, potentially generating 10% to 20% more electricity.

According to the National Renewable Energy Laboratory (NREL), floating solar farms could produce up to 10% of the nation's annual electricity consumption if installed on all artificial water bodies in the U.S.

Drawbacks of Floating Solar:

1. Higher Maintenance Costs: Floating solar systems are still new, especially in the U.S., leading to higher maintenance costs due to a shortage of skilled professionals. However, this challenge may lessen as more floating solar installations emerge across the country.
2. Impact of Water on Solar Panels: Although designed to be waterproof, constant exposure to water may still pose risks. If a panel gets damaged, prolonged water contact could worsen the issue. Despite this, the risk remains minor and should not discourage the adoption of floating solar panels.
3. Potential Disruption to Aquatic Life: The impact on aquatic ecosystems is still under study, but there is a concern that floating solar panels might disrupt these environments by reducing sunlight penetration and taking up space. The panels and their structures could pose risks to wildlife unfamiliar with these installations. The environmental impact on aquatic species is perhaps the most significant concern, as covering large water surfaces may reduce evaporation and alter thermal stratification, potentially affecting aquatic organisms.
4. Increased Pathogen Growth: Research from IWU indicates that floating solar panels could increase pathogen levels in water bodies due to shading effects. The reduced sunlight may create conditions that favor the growth of harmful microorganisms.

Cost Analysis of Floating Solar:

The cost of floating solar panels varies based on the size and location of the installation. Floating solar systems generally cost about 25% more than ground-mounted systems, primarily due to the higher expenses associated with floats and anchoring. In the U.S., the cost of floats ranges from $0.20 to $0.40 per watt (WDC), with additional overhead costs for handling, shipping, and upfront engineering.

However, floating solar systems benefit from installation costs that are roughly 50% lower, partly offsetting the higher structural expenses. Larger systems also benefit from economies of scale, reducing overall costs.

While floating solar systems are initially more expensive than traditional land-based systems, they offer unique advantages, such as reduced land use and lower water evaporation, which can enhance their overall value in specific scenarios.

Effectiveness of Floating Solar Panels:

Floating solar panels are an effective and increasingly popular method for generating renewable energy. These systems are installed on specially designed platforms anchored to the waterbed or shore, ensuring stability despite water movement. Installation involves assembling the floats and panels onshore before securing them on the water.

Similar to traditional solar panels, floating solar panels utilize photovoltaic cells to convert sunlight into electricity. This energy is transmitted through underwater cables to the grid or nearby facilities. A key advantage of these systems is the cooling effect provided by the water, which helps maintain optimal operating temperatures, resulting in higher efficiency, especially in hot climates. Studies indicate that floating solar installations may achieve higher energy outputs than land-based systems due to this cooling effect.

Global Trends and Future Outlook:

As of 2024, China accounts for over 50% of global floating PV system capacity, driven by land scarcity, low photovoltaic costs, aggressive renewable energy targets, and a growing market for floating solar. Asia continues to lead, followed by European countries, according to the International Renewable Energy Agency. In the next 5-10 years, other countries may also begin to catch up.