Firstly, I think everyone realises that space-based solar power makes no sense if you have to launch it from Earth on a current generation rocket at $20,000 a pound. The only economically viable plans I've seen for building them were based on building them in space from materials collected in space, and even they fell apart when you put real-world launch costs in there rather than NASA's 1970s 'out of the ass' numbers for the space shuttle.
Secondly, from what I remember, the designs I've seen used heat engines, not solar panels. Most of the spacecraft would be mirrors, not PV cells.
Space-based solar power may not make financial sense for decades to come (if ever), but that article makes about as much sense as those in the 1920s proving that you could never build an airliner that would carry more than a handful of passengers at more than a hundred and fifty miles per hour. They were perfectly true within the assumptions they made, but their assumptions were retarded.