Minnesota Transmisson Study Suggests Grid Upgrades for Renewable Energy
A new study released by the Minnesota Office of Energy Security shows that the state's power grid could accomodate 600 megawatts of new renewable energy capacity by making upgrades to electric transmission systems. A previous study had shown that another 600 MW could be added to the existing tranmission grid without impacting it's performance.
"Dispersed Renewable Generation Transmission Study Phase II" completes a two-part study chartered by the Minnesota legislature as part of the Minnesota NextGen Energy Act passed in 2007. The act calls for 25 percent of the total energy used in the state to be derived from renewable energy resources by the year 2025. In order to meet that goal, dispersed generation of the grid would allow many distributed power generators, such as wind farms, to add significant energy capacity to the system. Together, the combined studies created complex computer models designed to add 1200 MW of dispersed capacity by the year 2013.
Phase I, completed in June 2008, identified locations in the state transmission grid where a total of 600 MW of renewable energy projects could be developed with little or no changes required to the existing grid infrastructure. Although the study noted that dispersed generation can have impacts on the electric grid, it concluded that the majority of the 600 MW could be sited without disruptions at locations in southern Minnesota. In fact, in 2008 the state added 454 MW of commercial wind power with the vast majority sited in southwestern Minnesota.
Phase II of the study sought an additional 600 MW and found that there were limited locations in the state that could accommodate 10-40 MW generation projects without incurring some amount of transmission investment. So, the study team focused on sites that could potentially accommodate generation with only minor transmission investments, not the construction of new high-voltage transmission routes. The total cost of the transmission upgrades were estimated to be $121 million. In comparsion, the CapX 2020 project for constructing three new high-voltage transmission lines across the state is estimated to cost $1.7 billion.
As a result of the studies, the Minnesota Office of Energy Security concluded that achieving the renewable energy goal calls for a dual strategy of:
- Using our existing transmission infrastructure more efficiently, through increased energy conservation and efficiency, demand response, emerging efficiency technologies and dispersed renewable generation where it can be interconnected reliably, and
- Significantly increasing high-voltage transmission capacity in the state.
The studies and explanatory recorded webinars are available from the Minnesota Office of Energy Security on the link below.
Tom Wind (Wind Utility Consulting) acting as a consultant to Windustry served as a member of the Technical Review Committee for both studies.