In the heart of China, researchers are pioneering a method to harmonize the erratic nature of wind and solar power, potentially revolutionizing how we integrate renewable energy into our grids. Led by FANG Guo-hua from the College of Water Conservancy and Hydropower Engineering at Hohai University, a team has developed an optimal scheduling method for hydro-wind-solar complementary systems, using a concept called “standby flow.”
The challenge is familiar to anyone who has tracked the growth of renewable energy: wind and solar power are intermittent, making them difficult to predict and integrate into power systems. “The lack of prediction accuracy in wind and solar energy can significantly impact the safe and stable operation of the power system,” FANG explains. To mitigate this, the team introduced the idea of standby flow, a reserve of water in hydropower stations that can be released to balance the grid when wind and solar energy predictions fall short.
The researchers developed an optimal scheduling model that maximizes power generation and minimizes the variance of residual load—the difference between energy supply and demand. Standby flow acts as a buffer, smoothing out the fluctuations caused by unpredictable wind and solar energy. “Setting standby flow can balance the power supply and demand of the power system while ensuring power generation efficiency,” says FANG.
To test their model, the team conducted a case study on the cascade hydropower stations and connected wind and solar power stations along the lower Yalong River. The results were promising. In a typical wet month (June), the power generation efficiency of the multi-energy complementary system with standby flow increased by 0.08%. In a typical dry month (December), the increase was more significant, at 1.97%. Moreover, the variance of residual load decreased by more than 40% in both scenarios.
The implications for the energy sector are substantial. As more countries commit to increasing their renewable energy capacity, integrating these variable energy sources into the grid becomes increasingly important. This research offers a practical solution to enhance the stability and efficiency of power systems, making renewable energy integration more viable.
The study, published in the Yangtze River Academy Journal (长江科学院院报), provides a roadmap for future developments in multi-energy complementary systems. As FANG and his team continue to refine their model, the energy sector watches closely, eager to adopt strategies that can make renewable energy a more reliable part of our power mix. The future of energy is renewable, and with innovations like standby flow, we’re one step closer to making that future a reality.