We reveal the truth behind the hype-and how much money you may be wasting by buying into it. By Patricia Mertz Esswein, Contributing Writer December 1, 2009 If you’re like most people, you’re more than happy to buy green-as long as it also saves greenbacks. To that end, we’ve identified five green myths and the truth behind them-plus how much money you may be burning by buying into them. Myth: Never leave the lights on when you leave a room. Reality: Mom was right when it comes to incandescent bulbs, but not compact fluorescent lights. The more you switch CFLs on and off, the shorter their operating life. In most parts of the U.S. it saves money to leave fluorescents on if you will return to the room within 15 minutes, according to the Department of Energy. On average, a CFL bulb costs $2.50 more than an incandescent bulb, but it will save $5.41 annually on your electric bill compared with an incandescent. Sponsored Content Myth: You can trust product labels that say “green,” “eco-friendly” and the like. Advertisement Reality: The green-washing machine loves to crank out vague marketing terms, and the Federal Trade Commission has begun to crack down on environmental claims that fail the regulatory smell test ( visit www.ftc.gov and search “Sorting Out Green Advertising Claims”). Manufacturers have begun to improve labeling and offer better consumer information and advice on their Web sites, including lists and definitions of ingredients. Also look for the Environmental Protection Agency’s Design for the Environment label . Myth: Switching to solar is the best way to save energy. Reality: Even with government incentives, solar-power systems are expensive. The owner of a typical single-family home in the U.S. wastes almost $350 annually on heated or cooled air that escapes to the outdoors. So for most houses in most places, the first line of defense is to reduce demand. That means tightening up the house and its ductwork, improving insulation, switching to compact fluorescent light bulbs and upgrading appliances. After that, if you still want to go solar, you may be able to make do with a smaller system that costs less. For example, you might need only a 2-kilowatt system, which would cost $8,400 after the federal discount of 30% and an average state tax incentive of 25%. Myth: Energy savings and tax credits will eventually pay for replacement windows. Advertisement Reality: Single-pane windows may be energy wasters, but they’re not the biggest culprits. The home-energy tax credit, which is good through 2010, offsets 30% of your expenses, up to $1,500. Figure the average cost to replace a window is $300 to $700; if you must replace a rotten or damaged frame, the price rises another 50% to 100%, according to www.costhelper.com. So you could easily spend $5,000 to replace five or six windows, of which $3,500 would not be reimbursed. You can help prevent energy loss for less money if you follow the previous recommendations. Myth: You can neutralize your share of greenhouse-gas emissions with carbon offsets. Reality: Measuring your personal carbon emissions is a squishy science, and measuring the offsets is even squishier. For example, Carbonfund.org sets the cost to offset a round-trip, cross-country flight on an airline at $8.92 for 0.89 tons of carbon dioxide. Sustainable Travel International charges $45.34 for 1.8 tons. (The price of a carbon offset ranges from $5 to $25 per ton, on average.) Clean Air-Cool Planet, a nonprofit devoted to climate-science education, says that it’s impossible to prove that purchasing offsets will render purchasers carbon-neutral. And there’s no clear standard in use for certifying offsets, although the FTC is investigating the issue.