What infrastructure supports maintaining reliability when integrating high levels of wind and solar?

• A. Grid interconnections between regions.
• B. Isolated microgrids with no links.
• C. Increasing direct current only within a single site.
• D. Replacing all generation with manual operation.

Answer: (A)

Reliability with high wind and solar penetration hinges on linking multiple regions so power can flow where it's needed. Wind and solar output varies by location and time, so strong grid interconnections allow surplus power in one area to be sent to another that’s undersupplied. This regional sharing helps balance supply and demand, pools reserves, and supports stable frequency and voltage, reducing the chance of outages. Without interconnections, a region would be more exposed to local fluctuations and reliability would suffer.

Isolated microgrids with no links can’t borrow power from others when their own generation dips, which lowers reliability. Increasing direct current only within a single site doesn’t provide the cross-region balancing needed for a large, variable fleet. Replacing all generation with manual operation is impractical and would drastically reduce reliability.