It sounds like a typical left idea. Its all about seeming to do something for the environment, but actually doing nothing for the environment.
The issues, I have seen already apart from the issues raised in the video, is where are you going to get the material for the cells? The raw materials are fairly rare, and the cost of actually finding them will sky rocket due to the amount of demand this project's scale will introduce into the market. We can't dig to far into the ground, because the Left will then complain that we are destroying nature.
A E18 panel is going to cost $42,062 (including installation) for a 1.5x0.7m panel. You only going to get $33,000 out of a km of road, which means you need 1.2 years of perfect output to recover the cost of just one panel.
So yeah, this is just like every leftists idea. Sounds like the pink batts, BER and NBN all over again. Thank god we have had a change of government in Australia, I shutter to think how we could have survived the next 3 years with the Rudd/Gillard/Rudd government.