The offshore wind power industry has some way to go to prove it can take its place as a sustainable part of the energy mix, according to Offshore Proof, a survey commissioned by PwC of major players in the industry including developers, manufacturers and utilities firms. Cost and technological track record remain major challenges. For example, despite support for major expansion in Europe's North Sea, government bodies are split between positive and negative sentiment about offshore wind power. The coming five years will be a critical time for offshore wind power to turn promise into performance according to the analysis. But early experience of projects, as reported by developers, gives cause for optimism. The report also points out that the biggest challenge facing the industry is to bring costs down to a range where offshore wind power can compete in the energy mix with little or no subsidy. Available content includes shots from PwC's Headquarters and logos, as well as still images.