Consumer electronics like monitors, even in standby mode, can be notorious energy hogs that silently add to monthly electricity bills. Companies are coming out with smarter devices -- including power strips, plugs and electricity monitoring devices -- to help pinpoint and shut down such electricity eaters. If used correctly, the devices ultimately pay for themselves over years by cutting electricity bills and reducing greenhouse gas emissions.

P3 International's Kill A Watt

The Kill A Watt is a plug from P3 International that can determine the actual cost of consumer electronics based on power consumed by the hour, week or year. An LCD display on the plug displays the measured cost of consumer electronics. For example, it can measure the possible impact of an idle monitor or set-top box on an electric bill. Electricity charges from the utility company can be entered when setting up the plug.

The device is available for US$22 on Amazon.com.

Energy Detective

The Energy Detective from Energy Inc. is a system that helps users measure electricity usage in a home over a length of time, like a month. The system plugs into the power lines to monitor power supplied to a home, and a gadget with a tiny LED screen displays the results. For example, if a 10-watt bulb is switched on, the gadget displays the results within one second, according to the company. Data is logged on internal nonvolatile memory and can be transferred to a PC.

There's a caveat though: To use the system, a component needs to be installed inside circuit breakers that track inward supply of electricity. The company says the system could be installed in 10 to 15 minutes, but requires familiarity with electrical systems and circuit breakers. Do not install it if you are unfamiliar with electric systems, as any mishap could cause serious injury or death, according to the company. An electrician could install it for you.

The systems cost between $154.95 and $254.95 and are available at TED's Web site.

Monster power strip

Even in standby mode, consumer electronics like home theaters and PCs can be power hogs. Monster Cable's GreenPower PowerCenter surge protectors cut power supply to those consumer electronics, preventing energy drain and saving some dollars in the process. The surge protectors also save consumer electronics from damage due to power surges.

The surge protectors have color-coded indicators that help attach different devices to outlets. For example, the $79.95 GreenPower MDP 650 surge protector has six outlets with color-coded labels for computer-related devices like a PC, monitor, printer, accessory, router and speaker.