By Xinhua writer Yuan Quan
BEIJING, Dec. 14 (Xinhua) -- At work, Wang Zhifeng is a scientist specializing in solar thermal power research, but in his free time, he is an avid snow sports enthusiast. He has even covered one of the walls in his office with action shots of him and his family out on the slopes.
He has combined his two passions to envision an indoor ski resort powered by solar energy on a sunny island in south China. In his eyes, solar power has great crossover potential: It is a source of heating and can be converted into various forms of energy, including cooling.
"The Earth's energy comes from the sun, so solar power is highly efficient and can be transformed into lower-grade forms of energy, such as electricity, heat and chemical energy, both in theory and in practice," Wang said.
He works at the Chinese Academy of Sciences' (CAS') Institute of Electrical Engineering, which is at the forefront of China's solar energy research, and he has spent decades pushing the boundaries of how humans can harness the sun's power.
A prime example of this work is his current research on using the oldest energy source -- sunlight -- to fire ceramics. Through the precise adjustment of the angles and temperatures of solar concentrators, he has created a firing process that achieves zero carbon emissions. Solar-fired ceramics were exhibited at the 27th United Nations Climate Change Conference (COP27), showcasing the innovative application of solar thermal technology in the high-carbon industrial sector.
Wang has no shortage of brilliant ideas, pursuing cutting-edge research both on Earth and in space.
In 2021, he led a solar seasonal thermal storage project that stored summer heat for winter use over an exceptionally long period of 210 days, offering a sustainable solution for the challenge of solar energy intermittency.
This year, he expanded the application of solar energy into the field of lunar exploration, proposing a solar power generation program on the moon using technologies like axis-aligned concentrating solar cell arrays.
Wang and his team made history in 2024 by developing the world's first supercritical carbon dioxide (sCO2) solar thermal power generation unit, using solar energy and sCO2 as a working fluid to generate electricity.
"I felt quite anxious when I received the task," Wang told Xinhua. Back when the project was launched in 2019, no such power plant existed anywhere in the world. Similar initiatives had been set up under the EU's Horizon 2020 program and the U.S. Department of Energy's SunShot Initiative, yet none had succeeded.
As the project's lead scientist, Wang faced skepticism from his peers. However, after five years of dedicated efforts, he led a group of 18 research institutions to overcome the core challenges in equipment design and manufacturing, ultimately achieving sCO2 power generation at 700 degrees Celsius.
"This technology is key to cutting costs and, importantly, to ensuring round-the-clock power from solar thermal plants by tapping into stored heat after sunset or during bad weather," Wang explained.
The breakthrough made national headlines, with industry insiders hailing it as a huge leap. CAS academician Xu Jianzhong said, "Without Wang's dedication and perseverance, China's solar thermal power sector would not have come this far."
Along with the pioneering project, China's solar thermal power industry is also having its time in the spotlight, with steady growth in installed capacity, wider adoption of technologies and an increasing number of companies joining the sector.
At a time when emission reductions are vital, leveraging multiple forms of renewable energy is critical to meeting the demands of green transition. The development of solar thermal power generation has been included in China's first energy law, which came into effect on Jan. 1 this year. Both the central and local governments have also introduced policies to support the industry.
By the end of 2024, China's cumulative installed solar thermal power capacity had reached 838.2 megawatts, accounting for 10.6 percent of the global total.
When Wang entered the industry in the 1990s, solar power was still a niche field in China. While his university classmates went abroad or pursued business careers, he was among the few who stayed to continue research in China. He believed solar thermal power had a bright future, and his foresight was driven by an influence very close to home: his father.
Wang's father was an esteemed solar thermal power expert who was known as a workaholic among his colleagues. Answering the national call, his father left Shanghai in the 1950s for the remote, much poorer northwest to support national energy infrastructure, and in the 1980s, he began researching solar-powered architecture. Wang had been impressed by his father's selflessness, seeing that he would often voluntarily forego work benefits and prioritize his colleagues.
"That influenced me greatly, teaching me not to strive for personal gains," Wang said.
And he has truly lived by his father's values. Wang always attributes his achievements to the power of collaboration. When talking about nearly every major research project he has led, he expresses his gratitude to his partners, rarely mentioning his own efforts.
Solar thermal power stations are typically built in deserts or high-altitude areas where summer temperatures can reach up to 40 degrees Celsius and winter temperatures can drop to as low as minus 20 degrees Celsius. Researchers like Wang must travel frequently to work in these harsh locations.
A solar thermal power plant usually consists of tens of thousands of sophisticated mirrors, known as heliostats. Arranged on the ground in concentric circles, they track the sun like sunflowers, reflecting and concentrating sunlight onto a central receiver tower.
Wang's proudest work was an experimental solar thermal power station built in 2012 near the iconic Badaling section of the Great Wall in the suburbs of Beijing. The station has witnessed the completion of Wang's major experiments, from the first-generation technology -- solar-heated water at 400 degrees Celsius for power generation -- to the current, world-leading fourth generation -- solar-heated particles at 700 degrees Celsius for sCO2 power generation.
As it is near the Beijing Winter Olympic venues, the station's receiver tower was adorned with the Olympic rings in 2022, turning it into a local landmark. Wang named it the "Sun Tower."
At the experimental station, Wang is pioneering research into the solar-thermal production of ceramics and cement, operating at temperatures of up to 1,460 degrees Celsius.
"The significance of this research is not only in replacing fuels but also in its artistic value," he noted, adding that his future work is set to integrate science and art.
"Because the sun is different every single minute, each piece we fire has a unique texture, color and pattern," Wang said.
"It is truly a fascinating work." ■
