Advanced technology is being adopted to help the tomato industry flourish in the Yanqi County of northwest China's Xinjiang Uygur Autonomous Region, with the improved farming and processing procedures enhancing efficiency, lowering costs and ensuring better quality.
With long hours of sunlight and large diurnal temperature variations, Xinjiang has optimal conditions for tomato cultivation. The region ranks among the world's top three centers for tomato processing, while tomato sauce exports from Xinjiang make up 70 percent of China's total.
With September being the peak season for tomato harvesting in Yanqi, harvest machines are roaring back and forth through the more than 5,000-plus hectares of tomato fields across the county, sorting ripe red tomatoes from unripe green ones.
Local farmers note how smart technology is helping to almost instantaneously complete this otherwise rigorous process. "There is a specialized laser selection device inside the harvester, which can identify whether a tomato is green or red. If the tomato does not meet the standards, it will be ejected," said Xu Weizhen, a local tomato farmer.
With the help of this state-of-the-art tomato selection equipment, Xu said he has contracted dozens of hectares of tomato fields this year, making previously arduous work much simpler.
"In the past, harvesting our own one or two hectares of land took more than a week due to the lack of mechanization, and labor costs were significantly higher," said Xu.
Yanqi began cultivating and processing tomatoes back in the 1950s, and the county now contributes 40 percent of Xinjiang's total tomato output.
But while the emphasis is on delivering the best and freshest produce, even unripe tomatoes will not be totally discarded, as they will instead be supplied to local skincare and healthcare companies for their antioxidant properties and ability to combat sun damage.
"We have discovered that unripe tomatoes contain hexahydro- and octahydro-lycopene, which possess greater antioxidant activity and enhanced protection against sun damage compared to traditional lycopene, making them more valuable for skincare and health products," said Wang Xueming, an agricultural engineer.
As of 2024, the areas dedicated to growing tomatoes in Xinjiang have exceeded 80,000 hectares, with the entire processing tomato industry chain now being fully mechanized.
Over 200 companies in Xinjiang are producing a wide range of tomato products, including sauces, juice, lycopene, and seed oil, which are exported to more than 70 countries and regions worldwide.
Advanced tech transforms tomato industry in rural Xinjiang county
Major breakthroughs by Chinese scientists have laid the foundation for a future where space-based solar power stations are capable of wirelessly transmitting energy to Earth and spacecraft, though significant engineering problems remain.
A research team from Xidian University in northwest China's Shaanxi Province has made significant progress on the Sun Chasing project, or "Zhuri" in Chinese. The team has developed a ground-based test system for wireless power transmission that can charge multiple moving targets at the same time.
In recent tests, the system achieved a wireless power transmission efficiency of 20.8 percent from direct current to direct current over a distance of 100 meters. It delivered 1,180 watts of power. The team has also built a wireless charging system for drones. In a test, a drone flying at 30 kilometers per hour was able to receive 143 watts of stable power from 30 meters away.
A space solar power station works exactly as its name suggests: a huge array of solar panels placed in orbit. It would collect sunlight in space, where the sun always shines, and then convert that energy into microwaves or lasers to beam down to Earth or directly to satellites and spacecraft. This could address two significant issues: supplying uninterrupted power for space missions and alleviating energy shortages on the ground.
"The construction of space solar power stations could become a major undertaking in the future. One potential benefit is access to a virtually unlimited power supply. Because energy can be collected continuously in space 24 hours a day, electricity could be supplied on an uninterrupted basis," said Fan Guanheng, an associate professor at the School of Mechano-Electronic Engineering at Xidian University.
"Secondly, it could reduce our dependence on fossil fuels, thereby lowering carbon emissions and helping protect the environment. Thirdly, it could support the development of charging infrastructure in space and enable wireless microwave charging for spacecraft, changing the way power is supplied to space vehicles," the professor added.
In 2018, the research team launched the first phase of the Sun Chasing project to build a ground test system. By June 2022, they had completed the world's first full-link, full-system ground validation system for a space solar power station. Now, the team has moved to phase two. The goal now is to solve the challenges of generating high power in space and transmitting it efficiently over long distances.
According to Duan Baoyan, an expert at Xidian University and an academician of the Chinese Academy of Engineering, recent breakthroughs include improving the efficiency of solar energy collection and conversion, increasing the precision of microwave beam control to reduce energy loss, and making the transmitting and receiving antennas smaller and lighter, which is critical for space application.
The team has also solved the problem of how to power multiple moving targets at once using a single transmitter. This means that in the future, one space power station could potentially supply electricity to several satellites or ground vehicles at the same time, Duan said.
Despite the advances in ground-based validation, a series of technical challenges must still be overcome before the technology can be deployed in space.
"The first issue that needs to be addressed is the adaptability of components to the space environment, as conditions in space are completely different from those on Earth, including radiation exposure and extreme temperatures. Another challenge involves the deployment and retraction design of transmitting and receiving antennas. We also need to develop thermal management systems to cope with extreme temperatures and temperature fluctuations in space. These are all areas where further breakthroughs are needed," said Qian Sihao, an associate professor at the School of Mechano-Electronic Engineering at Xidian University.
"We have now completed the development and validation of a ground-based test system, and our next step is to carry out in-orbit wireless microwave power transmission," Fan said.
With ground validation complete, the team now turns its attention to overcoming the harsh realities of space, aiming to demonstrate in-orbit wireless power transmission and bring the vision of orbital solar energy closer to reality.
Space-to-earth solar power moves closer to reality although hurdles remain: scientists
