What is the impact of a solar eclipse on the power front?

Last summer’s eclipse caused a loss of nearly 6 GW of electrical power, giving researchers an opportunity to measure the impact of such a loss on the grid.
http://www.machinedesign.com/community/solar-eclipse-tests-grid?NL=MD-05&Issue=MD-05_20180626_MD-05_167&sfvc4enews=42&cl=article_1_b&utm_rid=CPG05000000559845&utm_campaign=18172&utm_medium=email&elq2=ecb0cff90bdf4fe39289ab54a5f7ef65