About one million hectares of land will be required in the United States by 2030 to meet solar-energy targets (go.nature.com/2g5hkg). Cultivating carefully selected plants on such sites could offer a sustainable solution to meeting growing food and energy demands, particularly in regions with limited agricultural land and water resources (see, for example, go.nature.com/acixb7 and go.nature.com/n2sysg).
Photovoltaics (for producing electricity) and photosynthesis (for producing food, fodder or biofuel) both need sunlight. Large solar infrastructures protect vegetation from intense sun and strong winds, and regular washing of their surfaces provides water for the plants. Crops could be grown in the spaces between these structures to benefit from concentrated rainfall. These crops would reduce dust from disturbed soils, which could otherwise lower the efficiency of solar installations, and they would create extra revenue and employment.
The benefits and trade-offs of such co-located systems are now being evaluated (see, for example, go.nature.com/acixb7 and S. Ravi et al. Environ. Sci. Technol. 48, 3021–3030; 2014). And solar operators and investors in North Africa, India, Mexico and the United States are already expressing an interest (S. R., personal communication).