In the first place, these things can’t be very effective. The dead give-away is that you can see through them. Solar panels work by absorbing light…. so if you can see through them, they’re not doing that job very well.

As for why they’re bunk, good residential solar panels are around 20% efficient. You heard that right, you get 20% of the energy in the light out as electricity. This is really really good. Current records for extremely expensive laboratory solar panels are in the 45% area. The maximum possible efficiency is around 85%, and the maximum efficiency anything that would work on a window will have (and not caring about whether you can see through it) is about 55%.

So in order for these to be 50x more efficient than rooftop panels, they’d have to at least have an efficiency of 1000%. Worse, because they go on windows, which are usually vertical, you’re losing a lot of light, as solar panels on rooves are normally placed on the south/north side of the roof, making sure they get maximum sunlight across the day. Worse, because they’re see-through, you know they’re not doing their job of absorbing light well.

So yeah. It’s an ugly product that ruins your view out of windows, all while being both less efficient, both in terms of power and cost.