What economical advantages does it have? The majority of the time it's still going to be cheaper to use 'dirty' energy.
If it was economically advantageous to use clean energy then all companies would be trying to use it asap
Well that's only true, if you don't factor in the cost of 'dirty' energy properly. You know, pollution, destruction of habitat, loss of fertile soil, health care costs, loss of human productivity etc. Right now the producers and consumers usually don't have to pay that cost, but the general population does, one way or the other, and usually in a different country.
One way to change that is by changing the laws worldwide and letting the people pay who are responsible, which some countries are doing.
Another (and probably easier) way is to make renewables cheaper than fossil and nuclear. Considering that renewables are ubiquitous, free of charge and .. well.. renewable and ergo will always be there in the long run, that's not such a hard task as many think.
A lot of countries are already producing mostly renewable energy due to their geography, Sweden, Austria, Iceland, Switzerland come to mind. But others are catching up.
Look at this way: if heavyweights as different as Germany and China are doing it on a large scale, it's probably wise economically and not just a hippie idea.