As people begin gathering at next week’s OFFSHORE 2011 conference in Amsterdam, it’s a safe bet that some conversations will focus on a just-released book by the International Energy Agency (IEA) which says wind power, solar power, geothermal energy and other renewables are now the fastest-growing sector of the energy mix.The book — Deploying Renewables 2011: Best and Future Policy Practice — adds that wind energy and other renewables offer great potential to address issues of energy security and sustainability, but their rapid deployment is also bringing a host of challenges.The IEA said on Wednesday that the new book analyses the recent successes in renewable energy, which now accounts for almost a fifth of all electricity produced worldwide (figure includes large hydro which is not included in the EU’s 20% renewable energy by 2020 target), and addresses how countries can best capitalize on that growth to realise a sustainable energy future.On the same day, Fatih Birol, IEA chief economist said that he would recommend EU policy makers to continue to support renewable development, if they want to go down in the history books. “Scrapping support mechanisms now would have dire consequences for the world,” he said.Deployment of renewable energy must be stepped up, IEA Executive Director Maria van der Hoeven said, especially given the world’s increasing appetite for energy and the need to meet this demand more efficiently and with low-carbon energy sources.

“Without an urgent and radical change of policy direction, the world will lock itself into an insecure, inefficient and high-carbon energy system,” Van der Hoeven said. “Renewables already play a central role in fostering sustainability and energy security, and their significance will only grow in the coming decades.”

The book’s executive summary said that hydro power is still the major source of renewable electricity (83.8% of RE generation, corresponding to about 16% of total generation in 2009) and will continue to be an important technology for years to come.

“The other newer RE electricity technologies have also grown rapidly, by an impressive 73.6% between 2005 and 2009, a compound average growth rate (CAGR) of 14.8%,” the summary added. “Wind has grown most rapidly in absolute terms and has overtaken bioenergy.”

The summary also said low–carbon energy technologies can deliver the intended policy benefits of improved energy security, greenhouse gas reductions and other environmental benefits, as well as economic development opportunities.

It added the market expansion of RE technologies has been accompanied by cost reductions in critical technologies, such as wind turbines and solar energy photovoltaic, and such trends are set to continue.

While some of the book’s conclusions will already be known to those attending the OFFSHORE 2011 conference, which is hosted by the European Wind Energy Association, they will no doubt back up a growing confidence that wind power is increasingly a key player in this century’s energy portfolio.