A study conducted by Minnesota public utilities in cooperation with the Midcontinent Independent System Operator (ISO) says Minnesota's power system can accommodate renewable generation representing up to 40% of retail sales in total with certain upgrades to existing transmission.
The study, directed by the Minnesota Department of Commerce with GE's Energy Consulting business serving as technical lead, determined that this level of renewable generation could be reliably achieved with only about 2% curtailment of renewable energy.
Wind and solar resources contribute significantly to voltage support and dynamic reactive reserves, the study says. Additionally, the fast response capabilities of wind and solar inverters can help with voltage recovery following a system fault.
GE says the Minnesota report contains findings similar to other recent studies that have been prepared with the assistance of its Positive Sequence Load Flow software, including one of the Eastern Interconnect (EI) for the U.S. National Renewable Energy Laboratory. That study considered the impact of 25% renewable penetration on frequency response on the EI system, finding that renewables at this penetration level could actually help with grid resiliency, GE says.
‘While 25 percent renewable penetration on the Eastern Interconnection is an aggressive target overall, the fact that Minnesota's system could reasonably accommodate 40 percent renewables penetration demonstrates the importance of evaluating the role renewable energy can play in the generation mix at regional and local levels,’ says Doug Welsh, technical director of GE's Energy Consulting business and GE project manager for the Minnesota study. ‘Not all electric power systems are created equal, and taking into account the unique aspects of individual systems can create a better understanding of the role renewable generation can play across the U.S. and around the world.’
The Minnesota study can be found here.