Have London Hydro's new Time-of-Use rates got you casting a suspicious eye at some of your appliances? Are you wondering just what it costs to run that space heater or beer fridge? Well, wonder no more - we have Kill-A-Watt energy monitors you can borrow to measure the cost of any 120V appliance that plugs into a standard wall outlet.. The monitor gives a reading of energy consumption in kilowatt hours. Learn more.