power plant in space

I stumbled upon this article about Japan spending 21 billion dollars to put a power plant in space. The power plant would send energy from space to the earth and be able to supply energy to 294,000 home with no cables. This seems cool and all but what are the health risks with this power plant. If it is "beaming" energy down on the people of Japan couldn't that energy cause cancer or other types of illness's? Is the price of the power plant really worth the risk of every person who lives in Japan? How about the price 21 billion dollars to build this thing and it wont even give half a million power? What happens if the power plant is damaged by something its not like you can just call up your local energy provider and fix it, they would have to send a space ship the space and its not like thats cheap. I think they are putting way to much money in to this project and not even providing enough energy for the whole country.