Harnessing the Sun, One Rooftop at a Time

CSU researchers discover that crops grown under solar panels produce higher yields due to the shade provided, while the plants, in turn, help cool the panels, enhancing their electricity generation efficiency.

Researchers at Colorado State University's Spur Campus in Denver are breaking new ground in sustainable urban development by integrating solar panels with rooftop gardens, an innovative practice known as agrivoltaics. This approach seeks to maximize the benefits of rooftop spaces in urban settings by combining renewable energy generation, food production, and environmental management.

Led by Assistant Professor Jennifer Bousselot, the project showcases how solar panels and green roofs can work in tandem to create a harmonious, mutually beneficial system. The team is cultivating a variety of crops, including chili peppers, lettuce, cucumbers, tomatoes, onions, and garlic, directly beneath the solar panels. The setup demonstrates how solar infrastructure and vegetation can coexist to address multiple challenges faced by urban areas, such as food insecurity, energy demands, and climate resilience.

One of the significant advantages of this system is its ability to shield plants from extreme heat. The solar panels provide a much-needed layer of shade, creating a cooler microclimate that promotes plant growth and reduces water evaporation. This protection is particularly vital in urban areas where temperatures can soar due to the heat island effect. Meanwhile, the plants offer reciprocal benefits by naturally cooling the solar panels, which increases their efficiency in generating electricity. Solar panels tend to lose efficiency when they overheat, so the cooling effect of vegetation helps optimize energy production.

Additionally, the integration of vegetation into rooftop spaces contributes to better stormwater management. Green roofs are known to absorb and slow down rainwater, reducing the burden on urban drainage systems. When combined with solar panels, these benefits are amplified, creating a multipurpose solution for dense city environments.

This project at CSU Spur Campus is more than just an academic experiment; it is a model for sustainable urban living. By demonstrating the feasibility of agrivoltaics, the researchers aim to inspire wider adoption of similar systems in cities across the globe. This approach addresses pressing issues such as climate change, urban heat, and the need for locally produced food, all while contributing to the growing demand for renewable energy. The initiative exemplifies how innovative thinking can turn unused urban spaces into thriving hubs of sustainability.