If that's an accurate number, it's down from more than $1000 per kilowatt-hour in 2007 to average an eight-percent yearly decrease. Working off the assertion that workable cost-parity with traditional vehicles can happen when high-capacity packs cost under $150 per kWh, Nykvist and Nilsson say we're ahead of the curve compared to previous predictions.
In fact, in their report published in Nature Climate Change, the two researchers suggest that advances in manufacturing, battery implementation, and economies of scale will play the largest role in getting pack kWr prices down to $230 by 2018. Major leaps in lithium-ion chemistry technology, they say, "have already been realized," and other technologies are still too early in development to predict. That will make reaching the $150 per kWh marker a difficult target, but in three more years we might only be $70 away.