Wind power can make up 30% of the generating base of an integrated power system without any major investment to secure stable supplies. Changes to operating procedures are all that is required. This is no longer the stuff of theory, but of real life experience. The catch is that relatively high levels of wind penetration require optimal use of transmission and distribution networks -- and the key to that use lies in the hands of politicians. Trading rules must no longer be allowed to work against wind -- and national borders must not remain artificial barriers to green electrons. Europe still needs its renewable energy directive (page 24).