What is the relevance of energy storage technologies in wind and solar power generation?

Grid scale Storage HW5

Use this article for homework5. Read chapters 9, 10, and especially energy storage chapter 18. Discuss the two types of grid-scale storage discussed in the article. What is the relevance of energy storage technologies in wind and solar power generation? Also, Include one additional reference other than the textbook and the article given for this last homework No citations including the in-text citation will result in automatic deduction of 5 points.