New US solar installations have nearly doubled, but slowing demand for both residential and large-scale systems, falling panel prices and concerns about looming federal tax reform are still dampening investor appetite for the sector. Solar installations soared 97 per cent to 14.8 gigawatts in 2016, according to a report released by Wood Mackenzie and the Solar Energy Industries Association. The technology is cheaper than ever, with panel prices dropping 40 per cent last year, and many utilities procuring solar on the basis of cost alone.