Sometime this month worldwide wind energy capacity will reach 10,000 megawatts - a record, and another demonstration that wind is the fastest growing of all renewable energy sources. The landmark figure for wind energy was announced at a meeting in Madrid of the Executive Committee of the International Energy Agency Implementing Agreement for Cooperation in the Research and Development of Wind Turbine Systems. The group is one of more than 40 international groups created by the IEA to pursue research of energy efficiency and new energy sources.