Now that brings up an interesting point. Here in the US, this likely wouldn't be a problem since they already like to drag out road work projects as long as possible. Back in my youth, I did some road construction work (for a private company - I mostly was working with my neighbor, who owned a trucking company, but he occasionally helped out his father, who owned a construction company, so I got to experience such wonderful things as spraying hot tar on a day when it was 95F and 80% humidity - there wasn't a better motivator for studying hard so I could get accepted at a good university) and if we as a private company ever took as long as these government jobs, the company would have been out of business for lack of work. No one would hire us if we worked that slowly. For example, they spent TWO YEARS on a 2 mile stretch of 4 lane road here, and all that got accomplished was some cracked sections of concrete were replaced - they whole road never got resurfaced, and now after one winter freeze/thaw cycle, it's as bad as it was BEFORE they "fixed" it.
Which is another point - I don't think they care if these solar roadway blocks last 5 or 10 years. They'll make a bundle, at taxpayer expense, replacing defective ones every year. It's public money, it's effectively endless to these morons. When the first private company paves their parking lot with these things, using their own money, not taxpayer dollars, then maybe we'll see. But I don't see too many lining up to foolishly waste their money when for less cost they can cover the roof of their building AND get better power output AND not have to worry about what happens in their parking lot. Then the "green" politicians turn around and say see, the government MUST fund this stuff because no one will invest. Yes, because no one wants to throw away money on bullshit.