What are the real-world impediments that stand in the way of accelerating the transition from fossil fuels to renewable energy systems? As many low-carbon energy sources have become cost-competitive or even cheaper than traditional fossil fuels, especially for electricity production, other roadblocks stand in the way of catapulting energy production towards a truly renewable and sustainable future. Do the problems stem from technology limitations? Political intransigence? Poor planning? Failures of imagination? Bad bets by hedge funds? All of the above?