Regarding Brian H. Potts’s “The Hole in the Rooftop Solar-Panel Craze” (op-ed, May 18): Mr. Potts is entirely correct that rooftop solar-energy production isn’t economically justified and wouldn’t exist as a viable option without considerable government subsidies. That is, for now.The average home in North America will need solar panels with efficiencies over 20%, combined with the effective storage systems that Tesla and others are now providing, to safely go “off the grid.” In the very near future high-efficiency solar panels with efficiencies well over 20%, costing no more than today’s most common panels, will ring in a new era of energy independence. The economic rationale for going off the grid will still vary greatly depending on the local cost of conventional energy and whatever government subsidies may apply. But the other very real advantages of becoming completely independent will continue to promote the adoption of the solar alternative, and competition for this market will drive the costs of solar-energy production and storage ever lower.
source: The Wall Street Journal