In November 2014, the Minnesota Department of Commerce released an engineering study that concludes Minnesota can reliably integrate renewable energy to meet 40% of annual retail sales by 2028. This scenario would require $373 million in transmission investments beyond current transmission expansion and upgrade plans.

Key Details

• Under legislation passed in 2013, Minnesota utilities and transmission companies were required to evaluate the reliability and cost of increasing Minnesota’s Renewable Energy Standard (RES) to a minimum of 40% of retail sales
• The analysis included three scenarios:
  • Baseline Scenario – assumes planned transmission expansions and upgrades are completed and retail sales from renewables are 28.5% by 2028
  • Scenario 1 – assumes retail sales from renewables increase to 40% by 2028
  • Scenario 2 – assumes retail sales from renewables increase to 50% by 2028
• Scenario 1 would require $373 million in investment (beyond the baseline scenario) for 54 mitigation projects, including transmission line upgrades, transformer additions/replacements, and changes to substation terminal equipment
• The upgrades would allow the electric system to be operated for all hours of the year with no unserved load, no reserve violations, and minimal curtailment of renewable energy
• Scenario 2 would require $2,567 million in investment (beyond the baseline scenario) to build nine new transmission lines and fund 30 additional mitigation projects, including market mitigation projects to alleviate congestion
• The penetration of renewables in the Midcontinent Independent System Operation (MISO) North and Central region was an additional key assumption in the analysis (see table)

                                                   Study Scenarios: Key Assumptions and Costs

Implications

Renewable energy integration costs increase dramatically with the addition of new transmission lines. When compared to the baseline scenario, studies show that Minnesota could increase the RES from 28.5% to 40% of retail sales with transmission upgrades. Achieving an additional 10% of retail sales from renewable resources would require new transmission lines and would result in nearly a seven-fold increase in integration costs.

More Information

Minnesota Department of Commerce: Minnesota Renewable Energy Integration and Transmission Study: Final Report

This report is part of the Clean Tech & Sustainability Minute series. To view all featured Minutes, please click here.