WASHINGTON, US.
Stronger US support for renewable energies would have allowed that
country’s power sector to reduce its CO2 emissions by up to 91% by 2030.
The Department of Energy analyzed the Low Carbon Economy Act (S. 1766) which
proposes a mandatory GHG allowance program to maintain covered emissions at
2006 levels in 2020, 1990 levels in 2030, and 60% below 1990 levels by 2050.
The analysis examined alternative technology assumptions and several energy
policies, including a fuel economy standard for vehicles and a 15% renewable
portfolio standard for electricity sellers.
The impacts of alternative carbon sequestration rates and assumptions about
the potential limited availability of nuclear, biomass and liquefied natural
gas were also examined.
"The electric power sector accounts for the vast majority of the emissions
reductions, with CCS (carbon capture & storage) serving as the key
compliance technology in most cases,” the report concludes. “The electric
power sector is projected to account for between 79% and 91% of the 2030
reduction in energy-related CO2 emissions in the cases examined.”
The reductions are achieved through the deployment of new coal plants
equipped with CCS, together with nuclear and renewable generating plants.
Many existing coal plants without CCS are projected to be retired early
because retrofitting with CCS technology is generally impractical.
In the core scenario, 300 GW of coal-fired plants with CCS are added by
2030, as much coal capacity as exists currently in the United States,
although the report concedes that “building this much of a
yet-to-be-commercialized technology by 2030 would be extremely challenging.”
In a scenario with high uptake of CCS, 128 GW of CCS capacity is projected
and, in these cases, renewables and nuclear technologies play a bigger role
in reducing power sector emissions. In a scenario where coal with CCS is not
available until after 2030, the power sector would turn to increased use of
natural gas.
"Only modest emissions reductions are achieved in the residential,
commercial, industrial and transportation sectors without additional
policies,” the report adds. Although some emissions reductions occur in
these sectors under the legislation, reductions are small when compared to
those in the electric power sector and increases in energy prices resulting
from the allowance program “are generally not large enough to induce
consumers to make large changes in their energy use.”
The 15% RPS for electricity sellers would have “little incremental effect”
because the GHG allowance program encourages an increase in green power
generation similar to what would be needed to comply with the RPS.
"The key uncertainties involve the potential for and the timing of the
development, commercialization and deployment of low-carbon electricity
generating technologies,” it adds. “Energy providers, particularly
electricity producers, will increasingly turn to technologies that play a
relatively small role today or have not been built in the United States in
many years, including coal with CCS, nuclear power, and renewable energy.”
Under a high technology scenario, lower early allowance prices reduce the
incentive to invest in CCS and CCS plays a reduced role while renewables and
nuclear become “relatively more cost effective.”
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