Geoscience Reference
In-Depth Information
BOX 1
HDD and CDD Methods and Impacts
Since 2007, there has been additional recognition
of the limitations of using CDD and HDD based
on a building balance point of 65⁰F (where the
building is neither heated nor cooled) to estimate
the efects of climate change on energy, particu-
larly peak electricity. There has long been recog-
nition that balance points difer between types of
buildings and between regions (they tend to be
lower for cooling and higher for heating in the
northern states, while the reverse is true in the
southern states. Adjusting these balance points
leads to lower estimates of heating savings in the
north and higher estimates in the south, while
cooling costs are increased in the north and low-
ered in the south. Several researchers beginning
with Belzer et al. (1996), recognized “dead zones”
between base points for heating and cooling and
fuel switching in heating and have worked out
ways to estimate the appropriate adjustments.
For example, these efects have been incorporat-
ed into models by Shorr et al. (2009), Miller et al.
(2008), and especially Hekkenberg et al. (2009).
In part due to computational burden, most cli -
mate change assessments of energy demand do
not use hourly temperature forecasts from climate
models.
industrial water heating, as well as increases in energy used for residential and commer-
cial refrigeration and industrial process cooling (e.g., in thermal power plants or steel
mills), there are no new studies documenting the extent of these potential changes. Since
the publication of SAP 4.5, more new research has been going on internationally than
in the United States (for a survey, see Mideska and Kallbekken, 2010). This section will
focus on the United States.
1) PROJECTIONS OF ENERGY CONSUMPTION
It is common for building energy demand projections to include temperature (often in
the form of heating degree-days [HDD] and cooling degree-days [CDD]) as control
variables to improve the precision of measurement in the income, price and other
higher or lower temperatures as a sensitivity test of the projected robustness (e.g., ER-
COT 2011. Analysts rarely investigate the impacts of systematic climate change on de-
mand forecasts.
EIA (2005) investigated climate change impacts as side cases for the Annual Energy
Outlook 2005. Warmer winters reduced residential and commercial building sectors' de-
mands for space heating, which in turn reduced projected cumulative total fossil fuel
use by 2.4%, but increased demand for space cooling and cumulative total electricity use
over the forecast period by 0.2%. Sixty-two percent of fossil fuels consumption in build-
ings, but only 16% of electricity, was in temperature-sensitive loads. EIA followed with
a side case for the 2008 Annual Energy Outlook (EIA, 2008) in which total building en-
ergy use fell by 2.4% and energy for electricity use increased by 0.7%. The net impact on