While these figures represent a very marginal difference, additional findings from FERC suggest that the gap is likely to widen in the coming months. The report notes that the US has been adding, on average, one percentage point to its renewable energy capacity every year, and predicts that by 2022 the technology will account for nearly a quarter of America’s total available installed generating capacity. Meanwhile, the nation’s appetite for coal continues to decline, with consumption dropping 39 percent from its peak in 2008, to its lowest level in 40 years.