Solar is not like other energy sources. Photovoltaic cells are a transformative technology, Alexis Madrigal, The Atlantic's senior technology editor, argues in the short video above. The faster the price of solar energy falls, the more viable it becomes as a source of clean power -- and the sooner we'll see it on roofs across America. Animated by Lindsey Testolin, this clip is part of a six-part video series in The User's Guide to Energy special report. For a more in-depth look at this topic, check out Kyle Thetford's "Charting the Fall of Solar Prices."