McCain says that market forces will solve our energy issues, but how can green technologies compete with big oil and coal? Last summer, at the national Solar Energy Conference in Cleveland, entrepreneurs and policy makers had lots of ideas on how government could help or hinder cleaner energy. Independent Producer Sandra Sleight (slight)-Brennan puts McCain's presidential promises in perspective . This story is part of the Promise Commentary series, an intimate look at the promises candidates are making this election year. All of them are free, compliments of CPB and the 100s of local stations who contributed to the PRX campaign audio archive. Check them out: http://www.prx.org/articles/1474