US - Utility-scale design and control system for a hybrid solar power plant
A team led by the Department of Energy’s Oak Ridge National Laboratory has announced that they have developed a utility-scale design and control system for a hybrid solar power plant that can operate with both direct and alternating current — providing more flexibility, security, and reliability than similar plants operating today. Hybrid plants include not only solar arrays, but also batteries, to store energy captured from the sun.
The multi-port autonomous reconfigurable solar power plant, or MARS, project integrates a complete suite of power electronics, electrical architecture and cybersecurity software in one package, simplifying deployment. ORNL and industry partners should be working toward an initial field demonstration of MARS components that support grid stability or a scaled-down version of the full design.
According to them, the majority of the U.S power grid uses alternating current, or AC, which constantly switches the direction of electron flow. In contrast, solar arrays and batteries use direct current, or DC, flowing in a single direction. The American electricity transmission system includes a smaller number of high-voltage DC lines, which are more efficient at delivering bulk power over long distances or to remote regions. Converting current between DC and AC requires specialized power electronics.
According to the project team, they developed case simulations based on two specific sites in California. Simulations in hardware revealed the significant benefits of the ORNL-designed power electronics framework for the electric grid: up to 50% reduction in power loss, a 16% improvement in stabilizing AC voltage frequency, and 100% detection of cyber intrusions such as malicious sensor data.
The project included an economic analysis which found that the MARS system reduced electrical costs by up to 40%. Researchers developed an algorithm to fine-tune plant size and energy storage to maximize annual revenue.
“You do not want the power grid to have significant losses of power when disturbances happen,” Debnath said. “Traditional renewable plants may disconnect from the grid or stop sending power, but we did not see that happen with MARS. It could cope better with failures in the external grid and continue to operate, supporting the broader power system.”
Source: Renewable Energy World