Storage is a problem; interestingly, I just read this piece: <a href="http:&#x2F;&#x2F;thinkprogress.org&#x2F;climate&#x2F;2016&#x2F;05&#x2F;09&#x2F;3775606&#x2F;used-second-life-electric-car-batteries&#x2F;" rel="nofollow">http:&#x2F;&#x2F;thinkprogress.org&#x2F;climate&#x2F;2016&#x2F;05&#x2F;09&#x2F;3775606&#x2F;used-sec...</a> about using retired car batteries as storage. There aren&#x27;t enough electric cars on the road to make this application widespread, but it may resolve some of the challenge over time.