CLIMATE ACTION PLAN - City of Urbana

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URBANA’S ENERGY USE
A. MONITORING ENERGY EFFICIENCY
Monitoring progress towards becoming more energy efficient involves comparing community-wide building energy
consumption data from year to year. However, some summers are hotter than others, and winter this year may be milder
than the last year. Therefore, energy requirements associated with space heating and cooling respond to fluctuating
weather conditions and a direct comparison of raw energy consumption data would be misleading as it does not
accurately reflect whether the community is becoming more energy efficient.
As a solution, we can compare annual energy use by plotting a graph of monthly energy use against monthly weather
conditions. This is done by normalizing community-wide energy consumed per month against a ratio of the Heating
Degree Days and Cooling Degree Days in that month.
Heating Degree Days (HDD) is a measure used to estimate the amount of energy required for residential space
heating during the cold season. Similarly, Cooling Degree Days (CDD) is a measure used to estimate the amount of air
conditioning usage during the warm season. To calculate HDD and CDD, 65 o F is assumed to be a comfortable indoor
temperature. The mean temperature for the day is calculated by taking the high and low temperature for the day,
adding them together and dividing them by two. If the mean temperature is at or above 65 o F, then HDD is zero, that
is, no energy was needed to heat indoor space. If the mean temperature is below 65 o F, the HDD equals 65 minus the
mean temperature. For example, if the mean temperature was 55 o F, then HDD amount equals 10. Similarly if the mean
temperature was at or below 65 o F, then the CDD is zero, that is no energy was needed to cool indoor space. If the mean
temperature was 75 o F, then the CDD amount equals 65 minus the mean temperature, amounting to 10. A monthly HDD
value and CDD value is reported by the Illinois State Climatologist for their weather station in Urbana.
By plotting energy consumed against a ratio of HDD and CDD, we can arrive at yearly trends that account for variations
in external weather conditions. This allows us to reach a more accurate yearly comparison of energy efficiency of the
building stock after eliminating those consumption changes that are a response to variable external weather conditions.
B. WEATHERIZATION
In October 2009, the City of Urbana received an Energy Efficiency and Conservation Block Grant (EECBG) to be used
toward reducing its carbon footprint. A part of this grant ($72,000) was used to create an innovative program in
partnership with Ameren Illinois’ Act On Energy Program. Through this program residents were able to benefit from free
residential energy audits and discounts on major envelope improvements. Under this program, residents of Urbana
were provided with a free energy analysis of their residence and a compensation of an additional 40 percent of the Act
On Energy Incentive available for Ameren customers for undertaking housing shell improvements, namely air sealing,
attic insulation and wall insulation. Between 2010 and February 2012, 826 Urbana homes were audited, and 169 homes
were retrofitted. Strategies to further reduce residential sector building energy consumption rely on securing additional
funding to continue the community weatherization program.
The Champaign County Regional Planning Commission Community Services Department also offers a Illinois Home
Weatherization Assistance Program (IHWAP) which is designed to reduce energy costs and improve home comfort levels
for low income residents. IHWAP is funded by the U.S. Department of Energy (DOE), the U.S. Department of Health and
Human Services (HHS), and the state supplemental Energy Assistance Fund. Between January and May 2012, a total of
982 units were assisted through this program countywide, including 177 multi-family units in Urbana.
City of Urbana
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