| Introduction |
| Energy performance is a subject few Americans consider before buying or operating an appliance or electronic device, even building or buying a home. This problem is only partially the result of lacking widespread educational opportunities for average consumers to learn about energy performance issues over which they could have more control in their lives. The problem is also influenced by an American culture and economy heavily focused on increasing consumer behaviors, processes and aspirations that demand rather than restrain regular growth in energy consumption, especially the consumption of electricity which is generated out-of-sight from where most consumers might directly see its negative consequences. Compounding this problem is the fact that many electricity utility companies still offer unit pricing which declines as a consumers usage increases. All this has led consumers to be confused, self-motivated or self-taught with respect to their energy awareness, use and cost expectations than they are in many other aspects of their lives. This has also created a situation in which individuals and households exhibit and tolerate wide variations in their energy consumption, energy expenses and sensitivity to environmentally negative consequences associated with energy. |
| The main goal of this report is to describe the results of a 2002 household energy survey of households in Southwest Ohio, Southeast Indiana and Northern Kentucky. The survey results are expected to demonstrate a wide variety of energy unit costs, annual bills, consumption levels and associated air pollution that may be seen as typical of households in this region. |
| A secondary goal of this report is to raise awareness about what seems best and worst regional home energy performance. This report’s author believes that most householders should benefit by seeing how well or poorly their own households perform compared with other local households. It is the author’s hope that poorer household performers might be motivated to reduce their own consumption by implementing whatever conservation, efficiency and renewable energy measures are most available, attractive and affordable to them. Even though this report does list energy efficiency and alternate energy measures reported by each household, there is no attempt to draw conclusions as to which particular measures are more or less effective than any others. Indeed, most of the better-performing households appeared to exhibit a variety of energy-efficiency and renewables features rather than just one or two. |
| After reading the rest of this summary below, if you want more information or a presentation about this or other surveys, contact Robbins. |
| Getting The Data |
| This survey is the result of numerous email and phone requests by energy consultant and home designer John F. Robbins for household energy information for calendar year 2002. Many contacts were participants in Robbins’ 2001 survey. The 2002 survey respondents include some of the 2001 participants, but not all. Some 2002 survey participants had not been part of the 2001 survey. Some 2002 participants had heard of the 2001 survey and contacted Robbins to be included in the 2002 survey. |
| Survey participants were asked to provide information about all the amounts, types and costs of energy they used in their homes during 2002. When there were revolving billing cycles which did not cleanly start or end with the calendar year, participants were asked to include only the energy for which they paid during the year, even if its actual volume overlapped somewhat into the prior or next year. Participants were also asked to provide the size of their conditioned space in square feet, the total number of occupants, how often the home was at "full" occupancy, how many occupants were typically home all day, their housing type (single or multi-family), and the county and state where the home is located. Also included in the survey were reported or known energy efficiency or alternative energy home features. The raw data was unverified and remains as reported by survey participants, with only a few minor exceptions. |
| Survey participation was voluntary and respondents were not selected scientifically. Only a few of the 29 participating households (four, including Robbins’ own) lived in homes designed or substantially influenced by Robbins’ design and consulting business. However, since survey participants did include other Robbins’ clients and volunteers who might be assumed more interested in being or learning how to be more energy efficient, this survey’s averages probably understate energy usage in truly ‘average’ households. This same reasoning could also lead one to suspect that this survey’s best performers may be somewhat more representative of efficient households. No attempt was made to substantiate either of these possibilities. |
| Describing Energy Performance |
| Local households in this survey experienced as much as 10:1 differences in their overall annual energy costs, as much as 5:1 in energy costs per person. Annual home energy costs ranged from $537 to $3162, per-person costs from $210 to $1054. Home energy cost measured per square foot of conditioned floor area varied as much as 3:1, the lowest being $0.35/sf and the highest $1.16/sf. Interestingly, one household, with 4 occupants in a 2400 sf newer home, achieved both the lowest energy costs per person and per sf. Also interesting was that the highest cost/sf household, with 4 persons in a 975 sf living space, achieved the 4th lowest energy cost per person, $283, suggesting that occupant density is an important factor for achieving energy efficiency in a home. |
| The household which had the highest 2002 energy cost, $3162, also had the highest per-person energy cost, the highest overall amount of annual energy use, 224,666 kBtu, and the greatest overall demand for carbon dioxide (CO2) emissions, 79,996 pounds. The highest CO2 emissions per square foot of conditioned space was 39.2 pounds/sf and per occupant was 28,037 pounds/person. |
| In contrast, the only off-the-utility-grid household in the survey was the least responsible for CO2 emissions: 3289 pounds, 2.74 pounds per sf, 1644 pounds per person per year. Interestingly, this off-grid household did not achieve best energy performance scores (BTU/sf, BTU/sf-degree-day, BTU/person) despite its superinsulated construction and small floor area. It was its avoidance of local utility-grid electricity (mostly generated from burning coal) which was responsible for producing its super-low CO2 demand. With heating often the major energy use for households in this region, it was not surprising that the four households in this survey with the lowest per-person CO2 demand all used other fuels besides electricity for heating. |
| All the less-than-40-cents/sf households resided in newer or remodeled homes with intentionally better thermal performance by design and/or construction, while all the highest energy cost/sf households resided in structures with little or no thermal efficiency improvements. No one kind of superior design or construction stood out dramatically as an obviously better overall energy performer. All of the five households with less than $300/person annual energy costs also had no more than 700 sf/person, suggesting again that house size per occupant seems an important factor for producing lowest energy costs per person. |
| Household energy efficiency was measured in this survey in two ways. First, all energy was converted to BTUs, divided by the sum of that year’s heating and cooling degree-days (dd), then divided again by the home’s conditioned floor area in square feet (sf). This provides comparable indices of energy consumption per size of house and severity of annual climate, most suitable for comparing different structures with similarly sized occupancy. Second, all energy was converted to BTUs, divided by the sum of that year’s heating and cooling degree-days (dd), then divided again by the number of household occupants. This provides comparable indices of energy consumption per person and severity of climate, most useful for comparing personal energy consumption. Noting that it seems more common to achieve better values in one of these categories than both, Robbins believes that the most efficient households should achieve high values in both categories. |
| The household with the lowest energy use measured against house size and climate had 2 persons living in a newer superinsulated 4000 sf home outfitted with a super-efficient HVAC system. This household used only 2.38 Btu/dd-sf, quite respectable for any home in a climatic region where 10-15 is considered average, 7.05 being the average in this survey. However, when this household’s energy use was measured against annual degree-days AND number of occupants instead of floor sf, it used double (4.73 kBtu/p-dd) what a 3-person household used (2.23 kBtu/p-dd) in a smaller (1000 sf) residence outfitted with presumably mere code-minimum insulation and HVAC equipment. |
| High/low ratios in both energy measurement categories averaged 6:1. With a wide variety of building envelope designs and HVAC efficiencies, plus differences in occupant density ranging from 1 person per 2000 sf to 1 person per 244 sf, only one household in this 2002 survey achieved SUPER (Robbins’ best) ratings in both energy performance categories. It also achieved the 3rd lowest CO2 emissions demand per person, 5549 pounds, excellent for an all-electric home (except for its efficient wood-burning fireplace) getting most of its energy from a mostly coal-burning electric utility company. The 2nd lowest CO2/person household used natural gas and firewood in its energy mix, lowering its average CO2/Btu to 58% of that of the SUPER energy-use household. |
| As might have been expected, the highest per-person CO2 emissions demand was achieved by a household living in an all-electric house without a non-electric primary or supplemental heating fuel. Although Robbins suspected that all-electric homes would be uniformly associated with the highest CO2 emissions, this did not turn out to be the case in this survey. The 2nd highest CO2 emissions per person occurred in a 3-person household, which despite using natural gas for most space and water heating, still accumulated the highest annual electricity usage. The 3rd highest CO2 emissions per person occurred in a 2-person household living in a well-insulated all-electric home which also burned a fair amount of firewood for supplemental heating. One household with an efficient thermal envelope and passive solar, but with an electric furnace without a heatpump, had relatively high CO2 emissions demand because of its increased reliance on inefficient electric resistance heat. |
| Varying Energy Unit Costs |
| Overall, average electricity unit prices from all surveyed households buying from utility companies varied from 4.1 to 10.8 cents/kWh, although 4.1 cents was so low that it was labeled "questionable." Using the more believable lowest average unit price of 6 cents/kWh from household #9, the range for utility-supplied electricity ranged + 38.5% to – 23.1% from an average of 7.8 cents/kWh. Average natural gas prices ranged from 63 to 83 cents/ccf, resulting in a range of +15.3% to –12.5% from an average of 72 cents/ccf. Two households buying propane demonstrated an average unit price range of +/-30.3% from an average of $1.98/gallon. |
| The lowest electricity use was by off-the-electric-utility-grid household, which bought all its reported electricity in "D" and "AA" disposable batteries, totaling only 2 kWh for the year. This household later admitted to recharging a laptop computer’s battery periodically when away from home. If recharged once each week over the year, this would likely have added at least 9-10 kWh to this household’s total, but since the frequency of recharging was neither confirmed nor paid for by the household, the initially reported energy use was not modified to include it. The $72.5/kWh unit price for electricity purchased in small disposal batteries represents the highest electricity cost reported in any past Robbins surveys or reports, even including costly electricity generated from PVs. But since this household bought only 2 kWh’s at this high price, it still had the lowest electricity cost, $145. |
| Among 2002 participating households, the least number of Btu’s purchased per dollar was 38 for two households, one in an all-electric house paying a rural electric cooperative an average 9.5 cents/kWh for its average 1353 kWh/month, the other a renter household paying Cinergy an average 9 cents/kWh for its average 282 kWh/month. The household getting the most Btu’s per dollar, 122, was in a thermally unimproved home paying Cinergy much more each year for its relatively lower-cost (per Btu) natural gas heating energy than for its electricity. |
| Another way households got more Btu’s per dollar was with free firewood, as evidenced best by the off-the-grid household, which burned more firewood than any other household in this survey. It should be noted that this off-grid household reported cooking as well as heating with wood fires. |
| E-mail: johnfrobbins@insightbb.com |