I was recently reading about JDS Uniphase's newest acquisition and was impressed. I didn't realize that a power over fiber product was as far along and as effective as it apparently is.
Here is a description:
Photonic power replaces copper and batteries for remote sensors, coaxial cable in wireless applications, and oil or gas-filled measurement transformers in high voltage applications. It delivers isolated power that is immune to RF, EMI, high voltage and lightning. Photonic Power Systems' technology can be leveraged across multiple markets, including medical, wireless communications, electrical power, industrial sensor, and aerospace applications. More than 10,000 units have been deployed to date, serving more than 50 customers.