Green gadgets keep your home office humming

Buy green, save greenbacks

Each year, the list of "green" gadgets gets longer, from solar-powered coasters or networked light bulbs. But some are a lot more useful than others. If you're looking for more than a novelty item, we've spotted ten devices that can save your company money by improving its energy efficiency. Some of them offer nifty, time-saving automation features and mobile apps too. Whether you're working from home or in a high-rise headquarters, these tools can put some energy dollars back in your pocket.

Kill a Watt EZ Electricity Usage Monitor

To make your workplace more energy efficient, you need to know how much electricity your existing electronics consume. P3 International's usage monitor removes some of the mystery. Plug anything into it—your PC, microwave oven, or NAS box—and it spells out exactly how much wattage the connected device uses. It even projects electricity expenses for up to a year. The company claims accuracy to within 0.2 percent. P3 International offers a full menu of smart-energy devices in addition to this one.

Price: $27

Smart Strip LCG3 Energy Saving Surge Protector

This power strip cuts off the flow of electricity to devices when they aren't in use, and it protects active devices from power surges. The LCG3 even knows to shut down peripherals when you're done using your computer. Ten outlets are laid out to receive plugs from your PC and peripherals. The strip is built to use less than 0.25 watt when all outlets are operating.

Price: $37

Belkin WeMo Automation Switch & Motion Sensor

Many devices don't need to remain perpetually turned on, but it's a hassle to switch them off one by one. To help you avoid wasting electricity, the WeMo Motion uses a motion detector to turn off electronics when you leave a room. It connects to your Wi-Fi network, so you can control power electronics remotely through an iOS 5 app when you're not around.

Price: $80

Leviton Occupancy Sensor

Occupancy sensors are a great way to reduce the energy suck of office lighting, which remains the biggest drain for businesses. After all, office workers are usually too distracted to remember to turn off the lights when they leave work. Leviton's ceiling-mounted sensor uses a Fresnel lens and infrared technology to get a 360-view of a room. It's hard-wired into lighting fixtures, and shuts them off when it detects that nobody is in the area. Potential energy savings per room vary drastically—from 15 percent to 90 percent.

Price: $77

Logitech Solar Keyboard

It may not make a dent in your office electricity bill, but this solar-powered wireless keyboard is a nice way to reduce the number of cords around your desk. Or maybe it's a fashion statement, to match the solar panels on your roof. The superthin keyboard doesn’t need to be situated in direct sunlight to charge: Indoor lighting from a desk lamp can do the trick. A full charge is supposed to last in complete darkness for three months.

Price: $53

Logitech Marathon Mouse

If you want to pair that solar-powered keyboard with a modest mouse, this Logitech model boasts a three-year battery life. It's supposed to require less than half the battery power of most other wireless mice.

Price: $44

Belkin Conserve Valet

This USB charging station can free up outlet space if you have several smartphones competing for a charge. It features four USB inputs, with a timer that shuts off the hub after 4.5 hours. When not in use, the Valet draws zero power. (Note, though, that you must remember to turn it back on if your device needs to charge for longer than 4.5 hours.)

Price: $38

Nest Learning Thermostat

Few people remember to turn off the lights when they clock out. Even fewer pay attention to the thermostat at work. The Nest removes manual labor from the equation. During setup, you choose a business setting, and the thermostat learns your workplace schedule to keep energy consumption to a minimum while still keeping employees comfortable. This product gets high marks for its elegant design. No surprise that it's the work of a former Apple iPhone design guru.

Price: $249 per unit + $119 for installation of first unit + $25 for installation of each additional unit

Philips Hue Connected Bulbs

Even though LED light bulbs consume 80 percent less energy than incandescents, their price remains dauntingly steep, with a starting price of $20 per bulb versus $1.25 for a CFL. But some recent LED bulbs do more than light up. Bulbs in the Philips Hue series come networked together, each with its own IP address. By using an iOS app and a bridge device, you can set lighting schedules and monitor energy consumption. You shouldn't have to worry about changing each bulb for up to 20 years.

Price: $200 for starter pack with bridge and three bulbs