Geoscience Reference
In-Depth Information
existing power plants or other stationary sources are subject to emission limits
for GHGs.
EPA'
S
NSPS
P
ROPOSAL FOR
EGU
G
REENHOUSE
G
AS
E
MISSIONS
As noted, the President directed EPA in his June 25 memorandum to re-
propose the NSPS standards for power plant carbon pollution. To understand
what issues the agency may address in the re-proposed standards, this report
discusses the 2012 proposal and several issues raised during its consideration.
On April 13, 2012, the Environmental Protection Agency proposed NSPS
for greenhouse gas emissions from electric generating units.
9
EPA called the
proposal the Carbon Pollution Standard for New Power Plants. By statute, the
rule was to have been finalized within a year, but the agency did not do so.
One reason is that the public comment period generated more than 2 million
comments, which must be considered in the development of a final rule.
Emission Limits
The proposed 2012 standard would have set a limit of 1,000 pounds of
carbon dioxide (CO
2
) per megawatt-hour (MWh) of electricity generated. This
standard can be met by new natural gas combined cycle plants without add-on
emission controls. Coal-fired plants, however, would find it impossible to
meet the standard without controls to capture and store some of the CO
2
they
produce. EPA estimates that a supercritical pulverized coal-fired power plant
without such controls produces roughly 1,800 lbs CO
2
/MWh of electricity, so
a plant subject to the standard would need to reduce emissions by about 45%.
Carbon capture and storage (CCS) technology that might be used to
reduce CO
2
emissions is the subject of much recent research and
demonstration.
10
It poses a number of challenges, not the least of which is the
additional energy it consumes. The energy required to run equipment that can
remove CO
2
from an emission stream (referred to as the ―parasitic load‖) is
currently in the range of 30% on most demonstration projects. In addition, a
CCS-equipped unit would incur costs for underground storage of the captured
CO
2
and possibly significant costs for building and operating a pipeline to
transport the CO
2
to the storage location.
