One of the first questions people ask me is
what is normal energy usage? Typically, this is followed by saying "I spent xxx dollars on electricity last month, is this too much"?
First, go to the Energy Star website and run the
Home Energy Yardstick. This will give you a general overview of how your home compares to national averages, normalized for your area's climate and home size.
Your electric bill can tell you quite a bit, but you have to know what to look for. In my area, PECO shows a graph on the bill that plots monthly energy usage over the year. Likely, usage will increase from April through July and August, then decline through October. It will then increase again through January and February and decrease through April.
As you can guess, this variation corresponds to the changing seasons. In Summer, air conditioning can significantly impact bills. In Winter, heating dominates and lighting increases because of the shorter days.
Closer examination reveals your baseline energy usage. By looking at the
shoulder months, April and October, you can determine your home's typical energy usage in the absence of air conditioning and space heating. These months likely show the lowest consumption. This tells you how much you use on other items like lighting, refrigerator, water heating, cooking and cleaning. Unfortunately, since they are all bunched together, you'll need other analysis methods to determine what fraction of your bill comes from each source.
Major Household Energy Consumers (not necessarily in order)
- Heating
- Lighting
- Refrigerators / Freezers
- TV / Computers / Electronics
- Cooling
- Water Heating
- Pools / Spas
- Cooking / appliances
Picking the Low Hanging Fruit
- If you're planning on replacing any of your appliances, do your homework! Go to the Energy Star website. Learn about your appliance and buy a replacement that is well rated. This particularly applies to high-consumption appliances such as refrigerators, air conditioners, dishwashers and clothes washers. If you use a dehumidifier, make sure you get a rated model as well as the new ones are quiet and very efficient.
- Replace high use light bulbs with compact fluorescent bulbs and fixtures. To get an idea of the impact this can have, if you replace two, 100 watt bulbs, like you might use outside your house, you can save 150 watts. Outside lights often run 10-12 hours per day, so those savings multiply to 1.5kw hours, every day of the year. This is likely 2%-5% of your entire electric usage! Imagine how much you'd save if you replaced more bulbs. Lighting is a huge consumer of energy in our country and with minimal expense or effort, you can make a difference.
- Seal your windows and doors - Improving the weatherstripping around your windows and doors can make your home more comfortable by stopping drafts. It can also save considerably amounts of energy. Cold or hot air entering your home through these cracks can waste as much energy as an entire wall. In fact, it is estimated that as much as 20-30% of a home heating/cooling bill goes toward conditioning this leaked air.
- Turn off computers - When idling, running a screen saver, a computer will draw a few hundred watts. When run 24-hours a day, this adds up to about 10% of your electric bill! Worse, many homes have several computers constantly wasting electricity. Use the hibernation feature to automatically put your computers into an energy saving mode after 10-20 minutes of non-use. Do not run programs like SETI round the clock. I made this mistake and had five computers running 24/7. My electric bill doubled for those months.
Detailed Example - Shaving Summer Bills
When you review your electric bill, look for big changes. For example, in my home, I found that summer usage tripled the baseline usage! I knew our air conditioner was old, but we didn't use it
that much. So I thought about what else we used during the summer that we didn't any other time of year. AHA! The swimming pool. Sure enough, the pool pump, running 8-12 hours per day, all summer long, consuming an outrageous amount of electricity. Replacing the pump with a properly sized, high efficiency model, saved approximately 15% of the total utility bill for the summer. The pump, which cost a few hundred dollars, will pay for itself in just a few years.
That still left a large increase due to air conditioning. Because I had been looking to replace both the heating and cooling systems, I decided to install a geothermal heat pump. This would greatly reduce heating oil usage in winter as well as electricity during the summer. This
expensive upgrade reduced my summer electric bills another 10-15%. Together with the pool pump, the resulting summer electric usage has averaged about 25-30% less than it did before.
These examples demonstrate the opposite ends of the remediation expense spectrum. The pool pump was an inexpensive and easy improvement. The geothermal system was costly and disruptive. However, both were worthwhile for me personally as they very significantly reduce my household's energy usage.
In doing your own analysis, you have to look at
why you're making the changes. Is saving money the primary goal? Or is that an added benefit of reducing your carbon footprint? You also have to evaluate the solution as it relates to your entire house, renovations, payments, etc. For example, replacing my air conditioner with a geothermal heat pump cost me about $18,000.
Initially, that seems outrageous, however, when I priced out a high efficiency air conditioner, that would have cost $8,000-$10,000 in my area. So the
incremental cost of the geothermal system was $8,000-$10,000. This still may seem too big a pill to swallow, however, it also allowed me to displace the use of an oil based system to heat most of my home. At current utility rates, this saves me $1,000-$2,000 per year.
Moreover, switching to electric based heat qualified me for a winter electricity discount. This was so significant that I calculated that the discount was like getting 100 gallons of free oil every month!
Adding up the savings led me to conclude that this
expensive upgrade was in fact a no-brainer. The system will pay for itself in under ten years, saves a huge amount of energy, and keeps my house comfortable year round.
Had I been building a new house, it would have been even more of a no-brainer. The incremental cost in your monthly mortgage payments is typically less than the money saved due to energy savings.
(to be continued)
This starts with a home energy audit, where I analyze the home, the historical utility bills, the homeowner's usage and their comments. This can also include a blower door test, duct leakage test and an infrared inspection.
homeowner and we determine what steps to take that will make the most positive impact on their happiness with their home. This might be a simple as caulking air leaks around windows and adding weatherstripping to doors. Or, it might included detailed suggestions for replacement heating/cooling systems, window replacement and even construction techniques for renovations.
