Energize Weekly, January 9, 2019
Texas—by taking advantage of its geographical diversity—could deploy enough wind and solar generation to meet the state’s electricity demand with little storage or fossil fuel backup, according to Rice University researchers.
“One way to reduce the need for costly storage and for polluting fossil generation is to deploy wind and solar capacity in a way that minimizes the times when their power is unavailable,” according to a paper published by Rice researchers Dan Cohan and Joanna Slusarewicz.
The researchers looked at ways to match renewable resources whose generating patterns were opposite—solar in the day and wind at night, for example—and regions that also varied.
The study measured the complementarity of wind and solar resources sited in various regions of Texas.
“We found that solar and wind resources exhibit complementary peaks in production on an annual and daily level and that West and South Texas wind resources also exhibit complementarity,” the study said. “Pairings of West Texas wind with solar power or South Texas wind sites yield the highest firm capacity.”
Texas already has the most wind turbines of any state in the country with 23,400 megawatts (MW) of generating capacity that provided 17 percent of its electricity in 2017. Solar contributed 1 percent of the state’s electricity.
Most of those turbines are located on West Texas plains, where the winds are strongest at night in the spring. The Rice analysis found that while not as strong a resource, turbines located in the Gulf Coast would generate most of their electricity in the summer in the late afternoon.
Solar was found to be a complimentary pairing with wind as there is a good solar resource across the state.
“Solar farms are better suited for providing power during summertime hours of peak demand, whereas wind farms are better for winter,” the study said. “Taken together, our results suggest that Texas renewable power production can be made more reliable by combining resources of different types and locations.”
West Texas wind paired with solar provided the highest levels of firm capacity at an 87.5 percent threshold.
“These results might suggest ways to organize future renewables projects to maximize reliability with minimal investment in expensive storage technologies,” the study said. “Such analyses will become increasingly important as the mix of Texas variable renewable electricity supply shifts from predominately West Texas wind to include more solar power and a broader mix of wind locations. ”
