From vision to reality - by 2050 Europe is scheduled to get around 15 percent of its power supply from the Sahara and other desert regions. Aglaia Wieland is head strategist at the Desertec Industrial Initiative (Dii), and Paul von Son chief executive. They are two of the key minds behind the implementation of the Desertec international energy project.The energy will be supplied by gigantic solar power generators and wind farms. Wieland and von Son are due to have a business plan completed by the end of next year. Many questions have yet to be resolved: how will they protect the solar panel reflectors from sand? How will the green power get to Europe? Plus there are new political challenges to be mastered. Who will be in charge of Egypt when the project gets off the ground, for example?