We were already impressed with transparent and flexible solar panels, but now those brainiacs at MIT have gone and topped that, printing one on a piece of paper for the first time ever. They did this with a process that works a whole lot like an inkjet printer. Notice their subtle flourish, where they printed the solar cell to spell out the letters M-I-T. Showoffs.
That sounds fantastic until you realize this seemingly miraculous feat yields solar cells that convert sunlight to electricity at a paltry 1.5% to 2% efficiency. That's lame compared to the 40% efficiency of conventional solar cells that populate the world's most spectacular arrays.
Alas, this solar cell printing tech is years from commercialization. Besides, we'd rather have our solar panels disguised as roof shingles, anyway.