Solar panels are seen atop the roofs of the Nokia Theatre and Staples Center at the L.A. Live entertainment district in downtown Los Angeles in this October 23, 2008 file photo. Fear of climate change and the need to find green alternatives to dirty coal, unpopular nuclear power and unreliable gas imports from Russia, are fuelling an embryonic movement in Europe to build "smart cities". To match feature ENERGY-CITIES/ REUTERS/Fred Prouser/Files (UNITED STATES)
REUTERS/FRED PROUSER