I know a leetle bit about this technology and i think the weight and size of any 'fuel cell' would be prohibitive to the design, the amount of charge you would get from a series of solar cells would not nearly be enough to power a 134KW engine, it may run your glass panel nicely though.
Putting the technology in a new airframe designed around this technology is a new ball game, i think the detractors are talking more about using an existing inefficient airframe design.
If you look at electric or hybrid cars you can see the amount of space taken up by the fuel cells not to mention the weight, on the ground this is not an issue, in an light Aircraft, these things are at a premium.
Solar power is useful to a point, i know its limitations it powers a bunch of my instruments (weather sensors and station) but its not nearly enough to power my irrigation systems which has much less draw than 134 KW!!!!