Criswell's idea is not a new one by any stretch of the imagination, such ideas have been bandied around concept labs for decades now. I have read a great number of articles on alternative power generation, and there seems to be a recurring problem with 'beam of ____ energy from space down to earth' ideas.

Consider this. Sphere A (the earth) is orbited sphere B, the moon. Sphere B rotates in such a way that one plane constantly faces A, while A rotates quite quickly. If you direct a laser beam from B to A, the laser will transit across the surface of A due to A's rotation. Even if you attenuate your antenna to track the receiving station, the circular locus of the beam will slowly become a very long ellipse, quickly covering a larger area than any practical receiving station could. Assume then that you want to 'turn off' the beam and switch to a different station. Easy enough, but space-based installations are notorious for breaking after long periods of time. Cosmic rays and micrometeorites will degrade the transmitter arrays, and inevitably one of them will lock on a particular beam vector. This could cause havoc depending on the type of beam used.

If it's plain sunlight, you'll create a laser-like beam that will scorch vegetation (you've used a magnifying glass on ants right?), heat-crack concrete and burn people alive. If at a lower intensity, people will still be blinded by the beam, and in the long term end up with skin cancer. If you're using microwaves, the problems (surprisingly) get exponentially worse. Although microwaves dont (seem) to affect humans much at the intensities we're talking about, they do have a habit of frying the hell out of anything electronic. Anything passing through that beam (which incidentally will be invisible, and moving at about 1000mph with respect to the earth's surface) will have it's electronics damaged or destroyed. This includes watches, pacemakers, cars, buildings and passenger jets.

Although the technology certainly is viable, the question is it's practicality. For such a station to ever be allowed, there would have to be a permanent moon-based maintenance crew (or several), to prevent what I have just described. This would multiply the costs by a hundred, as humans permanently on the moon need food, water, entertainment and shift changes. You cant exactly car-pool a quarter of a million miles. There will always be public opposition to any remote, unmanned facility beaming energy directly to earth - too much can go wrong. It conjures up old images of laser death rays from space ala Independence Day. Really what the world needs to do is stop using so much energy, but try telling that to the guy with the shiny new PC.