Environmental Engineering Reference
In-Depth Information
Despite these changes in US climate policy since the EIA's 2008 analysis, the broad
results of our analysis will likely apply to any similar Cap-and-Trade system.
Calculating Area Requirements
Our general strategy was to estimate reasonable most-compact and least-compact val-
ues of the amount of area needed to produce a certain amount of energy in a year, the
land-use intensity of production. We then multiplied the needed energy by our mea-
surement of land-use intensity of production (km 2 /energy/year) to obtain the “energy
sprawl,” the total new area needed for new energy production in that sector. Calcula-
tion of land-use intensity in this manner is useful for the goals of our analysis, allowing
calculation of the total new area impacted by energy development. It is similar to the
measurement of “area efficiency” [26], in that it does not attempt to account for site
preparation prior to energy production nor potential site reclamation after production
has ceased, which are sometimes considered in a full life-cycle analysis [3]. Ecologically,
over the time period of our study few sites will be reclaimed to vegetation approaching
their original habitat value [27]. Numerically, our land-use intensity values represent
a lower estimate because they do not include land-use during site preparation or rec-
lamation. While our methodology does not allow a full statistical analysis of the un-
certainty of our estimates, the variation between the least compact and most compact
estimates of land-use intensity captures most of the uncertainty.
Estimating areal impacts of new methods of electricity generation is relatively
straightforward. The EIA forecasts new power generating capacity needed (billion
KW), after accounting for likely retirement of existing generation capacity and the
nameplate capacity factors of different energy production techniques. We used values
from the literature to calculate the km 2 of impact per GW of new generating capacity
(see Tables 1 and 2). Our approach ignores the importation of electricity from Canada
or Mexico, on the grounds that this is predicted by the EIA to remain a minor compo-
nent of total electricity generation. End-use generation of electricity, which is tracked
separately for the EIA for several sectors, is considered to have negligible area re-
quirements, since it by defi nition occurs on previously developed sites. Similarly, the
energy effi ciency increases in the EIA scenarios are considered to have negligible area
requirements, since they occur through upgrades in existing building and infrastruc-
ture. We have not attempted to estimate the new area impacted by new long-distance
transmission lines needed to carry new capacity, as the length and location of new lines
is very uncertain and depends on future energy production mixes as well as federal and
state policy.
Our large-area estimates of land-use intensity of production are generally from
current operating plants, whereas our small-area estimates represent expert opinion
about expected future technological advances in effi ciency. The defi nition of impact
implied by these estimates was designed to match the majority of published studies of
the severity of impact on biodiversity, and thus varies slightly among energy technolo-
gies. For example, for hydropower we have assumed that new dam construction inun-
dates an area of terrestrial habitat, removing it of most of its native biodiversity. Note
also that the different categories of electricity generation derive from the EIA report.
For instance, the EIA chose to recognize solar photovoltaic and electricity from solar
 
Search WWH ::




Custom Search