Coastal areas in south China's Hainan Province on Saturday afternoon issued a red alert, the highest alert level, for typhoon Trami.
Trami is expected to circle over the waters from the southern coast of Hainan Island to the Xisha Islands on Sunday night, before moving eastward, gradually losing its intensity, according to the Hainan Meteorological Service.
From Saturday to Tuesday, Trami will bring strong winds and heavy rains to the sea areas near Hainan.
"Based on the current monitoring, Trami is expected to move westward at a speed of 10 to 15 kilometers per hour, gradually increasing intensity. As it approaches Hainan Island and the Xisha Islands, its strongest intensity may reach typhoon level. Starting Sunday, it will circle over the sea areas from the southern coast of Hainan Island to the Xisha Islands, and then its intensity will begin to weaken," said Wu Zhiyan, chief forecaster from the Hainan Meteorological Service.
The service maintained its Level-IV warning for typhoon on Saturday morning. Due to Trami, some sea areas around Hainan are expected to experience strong winds, and the Xisha and Zhongsha Islands will face intense winds and rainfall from Saturday to Tuesday.
On Saturday afternoon, the Sansha Municipal Meteorological Bureau upgraded the alert for the typhoon from orange to red in parts of Xisha Islands. A red warning for heavy rain was issued in the Yongle Islands of Xisha.
The Hainan Meteorological Service forecasts that Typhoon Trami will bring persistent strong winds and heavy rains to the Xisha and Zhongsha Islands, as well as sustained strong winds in the central South China Sea.
Trami also caused flooding in Yongxing Island on Saturday morning, drenching the streets.
China has a four-tier, color-coded weather warning system, with red representing the most severe warning, followed by orange, yellow and blue.
Chinese coastal areas issue red alert for Typhoon Trami
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
