Running an electric fireplace isn't expensive if you cull the one with a low wattage rating. Typically, a normal good quality freestanding electric fireplace uses 1500 watts of electricity. In the United States of America, the average cost of electricity is about .12$ per kWh. So, running a quality freestanding electric fireplace will cost 1.5Kw x $.12 = $.18/ hour. Assuming that your fireplace is 1500 watts and it will use 1.5 kW per hour.