Gauging Your Electricity Costs in Real Time

Similar in concept to many power companies' smart meters, personal monitors allow people to monitor the electricity usage in their homes and are getting much more attention lately.

The Energy Detective (TED) provides a real-time reading of your energy usage. That means, turn on a light, look at the reading; unplug your phone charger, check the reading. It even has alerts for when you're using too much energy. It can also show how much solar power you're generating, or if you have two monitors you could determine how much electricity you're giving back to the grid. The little monitor costs $140.

The PowerCost Monitor, available for $135, shows your total electricity costs in dollars and in kilowatt hours, and displays the time and outside temperature.

Another cool monitor, currently available in the United Kingdom, is the OWL. It displays your cost of electricity, your greenhouse gas emissions, and the temperature and humidity. It can also provide alerts when you consume too much energy.

Most of these companies claim the units can cut electricity costs by at least 20 percent, when read regularly.