The two traditional excuses for not adding more wind and solar into grid operations have been that they could not be called on (“dispatched”) when energy was needed and they were too expensive (“uneconomic”). But grid operators around the U.S. have begun to discover that neither is necessarily true.

“The New York ISO was the first to implement dispatchable intermittent resources in allowing wind to participate in economic dispatch and congestion management. It was thought of then as crazy to use wind for grid reliability,” said National Renewable Energy Lab (NREL) Senior Research Engineer Erik Ela. “Now almost every ISO in the U.S. uses wind this way. And we can go further and use more of the flexibility wind has to provide more support to the grid.” Ela said utility-scale solar can eventually do the same.

Researchers at NREL, the Electric Power Research Institute (EPRI) and the University of Colorado are working to demonstrate how the unique characteristics of wind and solar can, much like traditional generation, perform Active Power Control (APC) to support the grid. Researchers are especially focusing, Ela said, on two areas of APC, regulating reserves and primary frequency control.

“APC is control of power output to balance generation and load,” Ela explained. “Providing dispatch is one way of doing that. It can even do that in the faster time scales.” APC can support the grid during specific events such as when a large generator goes offline and the lost supply has to be replaced, Ela said. It can also steady the grid as load and renewables vary and require balancing.

via Making Wind and Solar Work With the Grid : Greentech Media.