That's the thing about exponential growth. It doesn't look like much at first, but soon enough, you have something big enough to change the world... According to numbers compiled by Solarbuzz, the global solar photovoltaic (PV) industry only had an installed base of 5 gigawatts in 2005 - and remember, solar panels have been around for decades, so it took a long time to even get to that 5 GW - and their are forecast to end this year close to 200 GW! Talk about rapid growth!
Growth should accelerate further over the next decade as solar becomes significantly cheaper than other sources of electricity, including polluting fossil fuels like coal and natural gas.
What's interesting about the solar power boom is that it's not being led by a single place anymore. At first, Europe was a clear leader thanks to very generous incentives. About 10 years ago, EU countries accounted for over half of annual demand for solar PV. But lately, they've only been around a quarter of demand, with Asian countries picking up the slack, and North-America finally joining the party in a big way.
But hey, this party's just getting started!