Prince Charles' wind-power movie premiers Britain's Prince Charles walks with a bouquet of flowers as he visits Common Good City Farm in Washington, D.C. on May 3, 2011. LONDON, April 29 (UPI) -- Robert Redford told a London audience the new film on wind power produced by Britain's Prince Charles is an important work in the environmental movement. Redford was on hand Saturday for the premier of "In Harmony" at the Sundance London film festival and told the crowd the movie was a tribute to the prince's dedication to preserving the environment. "This important film showcases his diligence, passion and achievement which include his efforts to amplify the work of social innovators on the front lines of change the world over," said Redford, the founder of the Sundance festival and a devoted environmentalist himself. The film focuses largely on the establishment of wind farms in Europe as a source of clean electricity. In the film, Charles says support for alternative energy is a gesture to future generation. I don't want my grandchildren, or yours, to come along and say, 'Why didn't you do something? You knew what the problem was,'" he said. The Telegraph said the premier of "In Harmony" came not long after Charles' own father, the duke of Edinburgh, had said publicly government promotion of wind generation is impractical and the concept of wind farms is "absolutely useless."