The Better Business Bureau has reported getting 21 complaints this month about a company that sells instructions for building a home solar and wind-powered system that "can slash your electric bill by 75% or more this month." Customers say merchandise doesn't arrive or a money-back guarantee is not honored. Power4Home, an Internet business with Minnesota contact information , sells a DVD and books for $47 that " offer little in the way of illuminating information," the BBB said. The same information is available on the Internet for free, the bureau said. A company video is narrated by self-described founder and electrician John Russel of Duluth. A message left on the company voicemail wasn't returned Wednesday.