Renewables: Big potential, lots of question marks

Clean renewable energy could meet a significant part of global energy demand, but it is still a long way from doing so

Many types of renewables remain much more expensive than fossil fuels, the infrastructure needed to scale them up is not in place in many countries – and the political will to take radical measures to cut global carbon emissions rapidly is largely missing. Wind turbines and solar panel farms are becoming increasingly common sights in many countries, but renewable energy still provided less than 20% of global power in 2008 – and that includes a sizeable contribution (15% of overall generation) from hydropower, a mature resource that has limited growth potential (see Figure 1). Where the renewables sector goes from here depends on a number of variables. Still key to achieving take-off will be