On the outskirts of Tauste, Zaragoza, a livestock farm has installed a floating solar platform on its manure lagoon to address high energy costs and harmful gas emissions. The system is expected to generate electricity for the farm while reducing the environmental impact of waste storage. It combines renewable power generation with the management of a facility that already occupies space on the farm.
Developed by Fotopur, the prototype consists of 16 solar panels mounted on a modular plastic platform floating atop a 1,100-square-meter lagoon. It covers about 10% of the lagoon’s surface. The panels sit on an aluminum structure designed to withstand the corrosive, ammonia-rich environment. The system is expected to produce 15.2 MWh of electricity annually, potentially meeting up to 53% of the farm’s energy needs. The operation previously relied on diesel generators and a small solar array for basic automation.
Open manure lagoons are common on pig farms in Spain. Pig manure, or slurry, is a nitrogen-rich mixture of feces and urine that may be stored near farms and later used as fertilizer. If it escapes from storage, nitrogen can reach surrounding waters through seepage into groundwater or surface runoff, including through drainage channels during heavy rain. Spain’s environmental rules include requirements for certain lagoons to be sealed to prevent contamination, making the containment and management of stored manure an impressive part of farm operations.
When manure is exposed to air, lagoons can release ammonia and methane, along with other gases. The floating panels put existing lagoon space to use and are intended to reduce emissions while generating electricity. This is especially valuable for farms with limited land, since it avoids dedicating additional fields to solar installations.
Technical Challenges
Building a solar array over a manure lagoon is more complex than installing panels on a roof or field. Corrosive gases can quickly degrade standard materials, so Fotopur’s design uses components selected for durability in harsh conditions. The floating platform also adapts to changes in lagoon water levels, helping keep the panels stable and functional throughout the year.
While the Tauste prototype covers only a fraction of the lagoon, a second trial in Zamora is testing a larger system: 56 panels with a peak output of 33.04 kWp, expected to generate 50.04 MWh annually. There, coverage can exceed 90% of the lagoon’s surface when plastic elements fill the gaps between panels. Early estimates suggest the system could cut ammonia emissions by up to 90%; ongoing measurements are intended to establish how the installation performs in practice.
Reducing Emissions and Diesel Dependence
For the Tauste farm, the solar platform is more than an environmental gesture. Isolated from the basic power grid, the farm previously depended on diesel generators for most of its electricity. The floating system is projected to cover more than half of its annual demand, reducing fuel costs and the farm’s carbon footprint. Fotopur notes that actual savings will depend on the farm’s specific conditions and the system’s performance over time.
The project also shows how existing agricultural infrastructure can serve new purposes. Turning a waste lagoon into a renewable energy source could help farms address environmental requirements and rising energy prices without expanding their physical footprint. Solar generation, but, complements measures to prevent manure leakage, runoff or overflow, rather than replacing them.
Scaling Up and Next Steps
Wider adoption will depend on corrosion resistance and whether maintenance can fit into daily farm operations. The modular design allows adjustments as lagoon levels change, while long-term durability and emissions performance remain basic considerations. Results from the Tauste and Zamora prototypes will help determine whether floating solar platforms can become a standard feature on Spanish farms.
New solutions for livestock operations are not limited to Spain. In a related example, Japanese researchers found that painting cows with zebra-like stripes could halve fly attacks, offering another approach to animal welfare and farm management. (Japanese study on livestock protection)
As energy prices and environmental standards continue to evolve, projects like the one in Tauste may point the way toward more sustainable and efficient farming practices across Europe.
