The Economist focuses on intermittency as the potentially most intractable problem, as the current generally accepted solution to intermittency is to rely on new, large scale, long distance transmission lines and lots of excess clean generation. All of this adds considerable extra expense and politically difficult land use issues for the very large number of new transmission lines. StratoSolar in contrast solves the intermittency problem by being above clouds and weather and thus not being intermittent in the first place.
By Edmund Kelly