I have a program that converts between units. Checking, it conveniently allows me to convert between mass and energy using Einstein's famous equation. So doing a little research, I could find out the logistics of powering the world entirely by antimatter.
In 2004, the world used 15TW (TerraWatts) of power. I'm going to assume that by next year, that this has doubled. This is only slightly less insane than it sounds, as people are inventing more electric-using devices on almost a daily basis, and multiple countries are converting from agrarian to industrial technologies, with industrial tech using far far more energy.
Assuming 100% efficiency, this would represent the loss of 1/3 of a gram per second. But let's assume that this process is only as efficient as existing power production, like coal. An industry site claims that coal is 33% efficient. That is, 33% of the coal's energy becomes electricity, the rest is lost to heat, smoke, and possibly noise. So I should multiply everything by 3.
1 gram per second. A gram, for those of you unfamiliar with metric, is about the weight of a paper clip. Of course, power plants aren't powered on a second-by-second basis, they probably buy a week's worth of fuel at any given time.
1 gram per second works out to 35 tons per year. Yes, that's quite a lot, but please keep in mind that this would be the entire world's use. In fact, there's very likely, within 100 miles of where I live, 35 tons of toxic waste that somebody is paying large amounts of money to get rid of.
Of course, this blog being highly idealistic and not at all practical, there's a big rub to this. Half of the 35 tons of material required to power the world would have to be antimatter. Antimatter is ludicrously expensive. NASA, one of the few organizations able to produce it, estimates that they could produce it at $25 billion per gram. So the power bill for antimatter power would be $7.5 x 10 ^17. This is, needless to say, more money than the earth has ever had in it's entire history. And that is not the end of the expense. The antimatter must be contained, lest it explode messily outside of the power plant's reaction chamber, causing more damage than an atomic bomb. Containment could very well add 3 or 4 more zeros to the end of that number.
Now you can see why, with current technology, antimatter power just isn't available.