To build a solar power plant, you need two things: lots of energy, and lots of silicon. The Sahara desert can provide scads of both, and by using power plants to 'breed' more power plants, the Sahara Solar Breeder Project will theoretically be producing enough green energy to power half of humanity by 2050.
The Sahara desert is about the size of the United States, and mostly empty. It gets about as much reliable sunlight as you could possibly hope for, but what really makes it a great place to construct a bunch of solar power plants is that the Sahara is completely buried in the raw materials for constructing solar cells: sand.
What the The Sahara Solar Breeder Project wants to do is build a silicon refinery out in the Sahara to start turning some of that sand into high quality silicon to make solar cells. The solar cells will produce electricity, some of which will be piped to Europe through superconducting power lines. The rest of the energy will be used to build and power additional silicon refineries, which will create more solar panels, and so on. The project will continue to breed with itself, producing exponentially increasing amounts of power, all from local resources, and eventually providing a full 50% of the electricity needs for the entire planet.
I probably should have mentioned that the third thing that you need to build a solar power plant is money, and predictably, that's what the project is waiting on. They'll need a couple million dollars a year to kick things off with a silicon refinery, but if they can get the basic infrastructure off the ground and start the breeding process, the project should be pumping out solar panel babies in about five years.