Where am I wasting electricity, heat, and worst of all, money? And how can I save those precious dollars while being less of a hazard to the planet?
As sustainable consumers, we should always be on the lookout for economical and easy ways to make our lifestyles more environmentally friendly. Rather than exhaust our bank accounts every time a new, “green” product is announced, we need to become smarter about what areas of our lives have the greatest potential for sustainability improvements, and what areas represent the easiest “fixes”.
In this article, we will examine statistics and calculations that will compare and extrapolate energy, monetary, and climate costs associated with different aspects of sustainable living. Many of the calculations included in this article were performed by the author, using data from the sources cited. Across many of these cases, there are other factors to be considered, the effects of which could be determined by a more detailed study. The estimations presented are intended to give the reader a rough idea of the energy costs that are associated with a few common, everyday tasks and processes.
Where Is My Energy Going?
In order to assess the overall environmental footprint of a household, it is important to first find out how much energy its individual systems consume. This is known as the end-use energy distribution. These figures show the percent of end-use energy applied to each set of tasks for residential buildings in the Midwest and the entire U.S. as determined by a U.S. Energy Information Administration study.
Space Heating
As shown in the U.S. end-use figure, 43.2% of the energy delivered to the average U.S. household is used to heat the house. Due to the colder average temperatures in the Midwest, this number increases to 51.7%. Clearly, therefore, if you are looking to cut back on the energy needed to keep your house up and running, the greatest opportunity for improvement lies in reducing your heating load.
In simple terms, the way to achieve this reduction is keep the cold air out and keep the warm air in. Each of these two concepts are addressed with a fairly simple technique. In order to keep cold outside the house, the basic insulation systems of the house must be improved. Within the walls, this can mean a few things: using more thermally resistant materials, creating a thicker wall, and layering different materials to provide a better heat barrier. Insulation is measured by R-value, which indicates thermal resistance to heat flow. The greater the R-value, the more effective the insulator. The R-values of individual materials can be measured, and these values can be added together if the materials are layered within a wall to calculate an effective R-value.
In addition to insulating the house well to prevent heat conduction through the walls, one must also address the actual loss of heated air to the outdoors through leaks in the house. These leakages are usually greatest near doors, windows, and vents that lead to the outside. While doors must be opened from time to time, maintaining a better seal when they are closed can greatly reduce the load on the space heating system.
Electronics
The above end-use distribution figure shows that the second-highest energy consumption in households can be attributed to appliances and lighting. While most of us strive to turn lights off and not leave our TV’s on when we’re not around, there is another significant consumer of electricity that many of us do not consider - or ignore.
Standby power, also known as vampire power or phantom load, refers to the amount of energy consumed by devices when they are powered off, but still remain plugged in. Almost all of our household appliances are designed to draw some power even when turned off to maintain certain functions and/or features. For example, most stereos have a clock display on at all times, while TV systems need to power the remote control receiver in order to detect the signal when you press the power button.
A Wisconsin Energy Center study tracked the phantom loads of many common household devices; the results are in the table at left. The effects of one device on its own are usually not very large. Even a treadmill drawing power constantly for one year (at an average rate of $0.10 per kWh) only costs you less than $5 over a year. However, most households have many appliances running on standby power at all time.
Consider a typical household with:
- 1 desktop with monitor
- 2 laptops
- 2 TV’s
- 1 stereo
- 1 printer
- 2 DVD players
- 4 Phone Chargers
- 1 Treadmill
The monetary cost of this household's standby power is only about $30 per year. However, the resulting emissions from the utility needing to produce this extra power may surprise you.
These figures show how much power is produced from different sources in both the U.S. and Ohio. By considering the CO2 emissions for each source, the heat rate in burning each fuel, and transmission losses along power lines, a weighted average of pounds of CO2 per kWh received in homes can be obtained. For the state of Ohio, this value was found to be 1.73 lb CO2/kWh. This means that about 500 pounds of CO2 is emitted just to power the above model household’s phantom loads each year. That’s approximately the same amount of CO2 emitted from driving a 25 mpg car for 640 miles !
Transportation
In a previous YellowLite post on electric cars and charging stations, we raised the issue of how much cleaner electric cars actually are. While direct operation of the car does not produce significant air pollutants, the environmental cost of producing the electricity used to charge the vehicle does.
Using the statistics for electricity generation in Ohio referenced above, we can calculate that a Chevy Volt, which uses 45 kWh/100 miles, would emit about 78 lbs of CO2 to travel those 100 miles. This assumes that all of its charging stations were connected to the standard power grid (no solar charging modules). This is about the same amount of CO2 as there are associated with driving a standard car that gets 25 mpg. Personally, I found this number a bit shocking. While the Volt is a fairly average electric car in terms of its efficiency (the Nissan Leaf uses 33 kWh/100 miles and the Tesla uses only 22), I still expected a drastic difference between the emissions associated with standard vehicles and those associated with electric ones.
These figures only represent a few areas that can be targeted in order to cut down on our environmental impact. Consumers looking to make their own sustainability improvements will need to acknowledge where energy and money are being wasted, and apply their own reasoning to determine an optimal solution for their scenario.
By Mattie DeDoes
Sources critical to this article are hyperlinked within the text.
