Thin-film solar technology is potentially lighter and more portable than your average solar panel. It’s frequently described as something you can “print” onto building materials or, as in the video I’ve embedded here, as a “label” — peel the backing off and stick it to something. (But, unlike Lisa Frank stickers, it absorbs light, rather than blinding passersby with it.)
It’s been around for a long time, but it’s a challenge to make thin-film solar efficient.
That’s why NREL has built a robot that can not only build thin-film solar but also analyze it: