Black & Decker. The Power Monitor tells homeowners how much electricity they are using in real time and the cost in dollars and cents. A wireless sensor attaches to the electric meter outside a home, monitors the rate at which electricity is consumed, and transmits the information to a handheld display monitor. Users can program cost-per-kilowatt-hour and billing plan information from their electric bills into the monitor. 800.544.6986. www.energysaverseries.com.