History was made this week in the world of clean energy transportation when the Solar Impulse 2 completed its flight across the world in Abu Dhabi without using a single drop of fuel. Perhaps it may seem odd that the solar plane landed in one of the world’s biggest oil producing countries, but the United Arab Emirates is actually emerging as one of the champions of clean energy. Along with being one of the main sponsors of the Solar Impulse 2, the U.A.E is developing what is set to become the world’s largest solar park that will produce energy at a record low $2.99 per kilowatt-hour. State-sponsored renewable energy group Masdar is also developing a self-sufficient, zero-carbon city of 40,000 set to be ready by 2030.