IEEE Spectrum has an interesting article on the future of high-powered microwave (HPM) weaponry, and its potential impact upon electrical systems and human organisms:

The application to information warfare is fairly obvious, but just how the onerous power requirements are to be met remains uncertain. Something in the order of 25 gigajoules of energy (the entire output of a coal power plant for 10 seconds) is required to drive one of the pulsed microwave beamsprototypes, which seems quite impractical for localised field work.

While the technology may be brutally effective for destroying technology (though ironically necessitating many billions of dollars worth of research and development), it could have other applications, such as the transportation of energy from one place to another. In recent submissions to a commission on the future of the United States aerospace industry, several proposals were made to establish large-scale solar power generators on a lunar colony, and beam the resulting energy to earth using HPM-based technology.

Of course, I doubt many people would be too keen on the idea of transmitting billions of human-vaporising-dolphin-killing-joules of energy to nearby storage facilities (safe though it could be). If this sort of thing was rolled out on a mass scale, it could quite easily meet the Earth's immediate energy requirements, or at least lessen the necessity for a fusion breakthrough. If the NASA task group investigating HPM technologies can obtain additional funding by emphasing the strictly military (or nationalist) applications of the technology, so be it - at least for now.