By Lou Carlozo, Green Dad columnist for dealnews Usually, I can justify a major expense if I know I'm helping the environment. And I can especially justify an expense that will also save money in the long term, like energy-saving electronics. But there's always the danger that so-called eco-friendly products only green the bottom line of the manufacturer, and not much else. This week, Green Dad sorts the fact from fiction when it comes to five products that claim to save energy. I'll do my best to give you the lowdown on how effective these items are, how long until you'll see savings on your electric bill, and whether you should consider buying them for (or banning them from) your household. 1. Product: Smart Strip LCG3 Energy Saving Power Strip Cost: $30.47 with free shipping The lowdown: Adapters for laptops and smartphones produce a "vampire effect" that uses a small amount of electricity when left plugged in, even if a device isn't attached to them. This strip blocks power to those plugs when not in use. The verdict: Plug in! The vampire effect accounts for 5% of energy use in the U.S., and this strip aims to hack away at that number. To calculate its value, let's conservatively say using the strip for your chargers and computer equipment (there are 10 outlets) could cut the "vampire" portion of your own electric bill to half the national average. If your electric bill typically averages about $100 a month, then this device will pay for itself in a year — and it will continue saving you money long after. Plus, you'll get the benefit of surge protection. 2. Product: Voltaic Spark Solar-Powered Tablet Case Cost: $299 with free shipping The lowdown: It's not just a case for your iPad or other tablet, it's a solar charger, too. The Spark can also charge smartphones and digital cameras, with one hour in the sun equaling one hour of video playback. The verdict: You probably won't make up the money in energy savings in a reasonable period of time, but consider some of the case's premium features that go beyond the average case: It's waterproof and UV resistant, and it can charge your tablet and a second device at the same time while on the go. So, while the cost of this carrying case / charger combo might not translate into the equivalent savings, its specifications may provide incalculable value in terms of convenience. 3. Product: Western Digital Caviar Green 2TB Serial ATA 3Gb/s Internal Hard Drive Cost: $99.99 with free shipping The lowdown: Green drives, such as this Western Digital Caviar model, eat less power largely because they spin at a slower rate than regular drives. The verdict: Does not compute to savings. If you're buying a green drive as part of an overall strategy to cut energy consumption on all fronts, it may make sense. But if you're doing it to dent the energy bill, you might be better off picking up loose pennies from the sidewalk. ars technica reports: "In terms of cost, using a green hard drive compared to a normal one makes very little difference ... netting you a whopping $5.38 per year [in estimated energy savings] for your sacrifice of 1800 rpm. For comparison, changing one 60-watt light bulb used four hours a day to a 7-watt fluorescent one saves you more, about $9.23 per year." 4. Product: Viatek G-ENER-G Power Saving Device Cost: $36.99 with free shipping The lowdown: Energy Saving Devices are supposed to help you lower your electric bill, either by cutting down the voltage that arrives at your appliance, or the amount of current used. The verdict: Nothing to get charged about. The overwhelming evidence says that these devices don't produce the savings that the hype might suggest; in fact, they could even harm motorized appliances, such as fans, by forcing them to work harder to achieve the desired effect. AdvancedEnergy.org puts it like this: "Testing of devices that tout energy-savings for homeowners who use them on major appliances has revealed that most buyers are simply being snookered." 5. Product: Philips 12-Watt Ambient LED Dimmable A19 LED Bulb Cost: $39.97 with free shipping The lowdown: As the newest wrinkle in lighting technology, LED bulbs may look expensive, but boy, do they last long — make that more than 40 times longer than an incandescent bulb. The verdict: The proverbial bright idea. Since an LED bulb will last 50,000 hours, you'll come out way ahead on energy and cost savings. According to eartheasy.com, if you replace 30 incandescent bulbs in your home with LED bulbs, you'll realize a total savings in excess of $13,000 over the life of those LEDs. But that's a small bonus compared to the amount of strain you'll save from climbing a ladder to change ceiling fan bulbs every few years as opposed to every few months. All items mentioned are available at the lowest total price we could find from a reputable seller at the time the story was published. Lou Carlozo is dealnews' Green Dad columnist. He was most recently the managing editor of WalletPop.com and, before that, a veteran columnist at the Chicago Tribune. Follow him on Twitter— @LouCarlozo63. You can also sign up for an email alert for all dealnews features.