Moving crops into solar-powered ‘plant factories’ across China could free up swathes of land, slash fertilizer emissions, and meet the country’s vast demand for vegetables, a new study shows.
What’s more, these indoor farms would be powered by China’s surplus of solar and wind energy—taking care of the huge cooling and heating costs that usually make indoor farming unrealistic and impractical. However, as the new research revealed, this solution also carries some significant caveats.
China is a fresh produce powerhouse: it is the world’s largest exporter and consumer of vegetables. So it’s a global worry that China’s produce is increasingly under threat from changing weather patterns, pests, and disease. That’s why the researchers wanted to investigate the potential of indoor farming in the country (which they describe as ‘plant factories’ in the paper) to shield the industry from climate change.
To explore this, they looked at over 300 regions near to Chinese cities and modelled their renewable energy potential, and how well they could accommodate indoor farms. In each case they mapped out the factories’ greenhouse gas and pollutant footprints too, and looked at strategies to bring down carbon impact, where possible.
Most immediately striking was that on the available land, indoor farms would produce enough to “fully meet the dietary vegetable demand of the population” the researchers say. Meanwhile, moving crops indoors would also free up 51,370 square kilometres of currently-farmed land. “The conserved cropland can either be used for staple food production or be returned to forest,” the researchers note. Indoor farming would also reduce nitrogen runoff by up to 186,000 metric tonnes compared to conventional agriculture, the modelling showed.
As well as this, the widespread plant factories would require just 5% of all of China’s renewable energy potential—small enough that even if all of China’s energy demand was ultimately supplied by renewables, there would still be enough leftover to fuel the lighting, heating, and cooling of these indoor farms.
When researchers factored in the costs of buying the land to develop plant factories, manufacture the renewable energy infrastructure and the factories themselves, they found that the overall costs per kilo of vegetables remained affordable, at 5.88 Chinese Yuan (about $0.83). Partly, this was due to the economic benefits gained from cropland conservation, the team calculated.
But—and this is a significant caveat—the large carbon footprint associated with making the solar and wind infrastructure required to power these farms ironically offsets the carbon savings of the renewable energy itself. In fact, indoor vegetable farms would double the greenhouse gas emissions associated with conventional farms.
This would seriously impede the sustainability of indoor farming, but the researchers are optimistic that this challenge can be overcome.
In their model they also explored a series of nine measures to reduce the overall footprint of plant factories, including low-carbon manufacturing of plant factory materials and the renewable energy infrastructure, improved lighting and cooling efficiency, relying on clean transportation, and reducing vegetable waste. In combination, these could bring the overall carbon footprint of plant factories down by 70%, which would be in line with conventional farming methods, their model showed.
Closing that emissions gap would require coordinated efforts across the vast network of indoor farms, which could be a challenge. But perhaps that shouldn’t overshadow the several other “multifaceted benefits” the researchers describe in their paper: the significant land-sparing and avoided fertilizer emissions, and improved food security that indoor farming could deliver.
They see potential far beyond China too, believing that plant factories hold real promise in regions with limited arable land and challenging climates such as the Middle East, parts of Africa, and South Asia.
With the global population rounding up to 10 billion by 2050, and climate growing less predictable all the while, the researchers seem confident that upscaling indoor farming could provide the “promising transformation” needed to meet these future challenges. But clearly there’s still a long way to go to reach that reality.
Wang et. al. “Renewable-fuelled plant factories ensure large-scale food supply but require low-carbon transition for environmental gains.” Nature Food. 2025.
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