Imagine that you bought an ice cream cone — say, two scoops of Rocky Road with sprinkles on a vanilla cone, costing you $2.70 — and you then decided to walk the mile to your home and eat your ice cream cone there. So you put the ice cream cone in your backpack, trek home and pull it out to eat, only to discover that two-thirds of it has melted. In essence, you paid $2.70 for about 90 cents worth of ice cream.
Not a smart decision, but it illustrates a point with respect to energy use. Using electric appliances in your home, be it an electric water heater, heat pump or stove, is a lot like that ice cream cone. From the point of origin, whether it’s a coal mine or a natural gas well, to the place where either of them is generated into electricity — usually a central station power plant — to the electric outlet in your home, electricity loses about two-thirds of its useable energy. Most of that energy loss occurs in the generation process.
By contrast, natural gas’ journey from the wellhead through transmission and distribution pipelines directly to the natural gas furnace, boiler, fireplace or stove in the home loses only about 10 percent of its usable energy. Thus natural gas is far more efficient than electricity.
What is more, going back to that ice cream cone, what happened to the two-thirds of it that melted? It melted into your backpack, or through your backpack down your pants leg or skirt, onto the ground, making a mess. Similarly, during the electricity generation process, not only is a lot of energy lost, so is a lot of pollution released into the atmosphere — especially when coal is generated — making a mess of our air. Very little pollution results when natural gas, by far the cleanest fossil fuel, is burned in those gas appliances in the home.
The point is that when energy is measured from the point of origin to the point of use — what we call the full-fuel-cycle measurement — it becomes obvious that natural gas used directly to power natural gas appliances in the home is far more efficient and environmentally friendly than using natural gas, or coal, to generate electricity to power electric appliances in the home. Unfortunately, today when the Department of Energy (DOE) rates the energy efficiency of a natural gas or electric appliance, it bases that energy efficiency solely on a site measurement—that is, how energy efficient an appliance is “on site,” meaning in the home. That ignores all of that energy lost, and the pollution created, from the point of origin to the end-use appliance.
Recently, the well respected National Academies issued a report to DOE titled “Review of Site (Point-of-Use) and Full-Fuel-Cycle Measurement Approaches to DOE/EERE Building Appliance Energy Efficiency Standards.” The report recommends that DOE consider changing its measurement of appliance energy efficiency from site-based to one based on the full-fuel-cycle. That would give consumers far more accurate information on the true efficiency and environmental impact of the energy appliances they buy. The goal is to reduce energy use, reduce greenhouse gas emissions and save consumers enough money to buy the whole family an ice cream cone — two scoops with sprinkles — anytime they want.