The Bellingham Herald reports from Bellingham, Washington, that Puget Sound Energy (PSE) is going door-to-door to manufactured home owners, offering free energy-efficient devices valued at $500.  Any PSE customer that has forced-air heating is eligible for upgrades that include energy efficient light bulbs, water faucet and shower head aerators, pipe wraps, and air filter replacements.  PSE says the 6,700 manufactured  homes in Whatcom County that qualify can save 30 percent in energy costs.  The program will continue through September.