This McKinsey report, “Solar power: Darkest before dawn” finds that underlying PV costs are likely to continue to drop as manufacturing capacity doubles over the next three to five years. Indeed, the cost of a typical commercial system could fall 40 percent by 2015 and an additional 30 percent by 2020, permitting companies to capture attractive margins while vigorously installing new capacity. The research suggests that the overall solar market will continue to grow.