In 2007, the Electric Power Research Institute (EPRI) released its first “Prism” model and Model for Estimating the Regional and Global Effects of Greenhouse Gas Reductions (MERGE). According to EPRI, these analyses provided a technically and economically feasible roadmap for the electricity sector as it seeks to reduce its greenhouse gas emissions over the next four decades. The Prism analysis provided a comprehensive assessment of potential CO2 reductions in eight key technology areas of the electricity sector. The MERGE analysis identified the economically optimum technology portfolio in response to a given CO2 emissions constraint.
EPRI updated both analyses in 2009 to reflect economic and technological changes that have the potential to affect projected emissions and the technologies to address them. This update is also more comprehensive in that it includes new technologies and analysis features.
The Prism analysis determined that the electricity generating sector can potentially meet the challenges that confront each technology option and deploy “The Full Portfolio” of technologies to achieve meaningful emissions reductions. The full Prism graphic builds from the top down, utilizing the U.S. Energy Information Agency’s (EIA) 2009 Annual Energy Outlook reference case estimate of CO2 emissions from the U.S. electricity sector. This summary provides an overview of key factors, technical assumptions, and research, development, and demonstration (RD&D) priorities for each technology.
The MERGE analysis determined the most economic combination of technologies over time to meet a specified CO2 emissions constraint. Based on current and projected technology costs, consideration of fuel costs and reserves, and competition for resources with other parts of the economy, MERGE projects electricity generation from different technologies, electricity costs, CO2 prices, and the overall cost of implementing CO2 emissions reductions.
The 2009 Prism and MERGE analyses show that a full portfolio of electricity sector technologies could simultaneously address the challenge of growing load demand while meeting carbon constraints and limiting (in relative terms) increases in the cost of electricity. The research shows that the sector could potentially reduce annual carbon dioxide (CO2) emissions in 2030 by 41 percent relative to 2005 emissions levels, but that it will require sustained research, development and demonstration and aggressive deployment of the full technology portfolio.
Full Portfolio
The full portfolio includes coal-fired generation with carbon capture and storage, renewable resources, and nuclear generation, as well as significant efficiency improvements throughout the electricity production and delivery system and reduced consumption through end-use efficiency. It requires deployment of advanced technologies by 2030 comparable to those assumed in the Prism analysis; an 8 percent reduction in electricity consumption through improved end-use efficiency; 45 new nuclear units; new renewables generation equivalent to four-fold increase in current wind and solar generation capacity; and 100 million plug-in electric vehicles.
The results indicate that the full portfolio could reduce the cost to the U.S. economy, of funds that would otherwise be expended, for CO2 emissions curtailment by more than $1 trillion by 2050. Deployment of the full portfolio could result in an 80 percent increase in the real wholesale cost of electricity by 2050 relative to current costs, compared with a projected increase of more than 210 percent with a limited portfolio.
2009 Prism Analysis
2009 Prism analysis assumption: Achieve “maximum achievable potential” as calculated in the 2009 EPRI efficiency study, resulting in a 2030 net consumption reduction of 8%.
The 2009 Prism analysis estimates that the technical potential exists for the U.S. electricity sector to reduce annual CO2 emissions in 2030 by:
· The 2009 analysis estimates a potential CO2 emissions reduction in 2030 of 6.5% as a result of gains in energy efficiency.
· 41% relative to 2005 emissions, based on improvements to electric sector technologies;
· 58% relative to 2005 emissions, if reductions due to electrotechnologies and electric transportation are included; and
· 62% relative to the 2030 reference case projection in the Energy Information Administration’s 2009 Annual Energy Outlook1. (Emissions reduction potential for each technology area is also expressed as a percent reduction relative to this reference case.)
The Prism analysis projects that by 2030, 60% of the total U.S. generation mix would consist of low- or non-CO2 emitting generation—provided that the required research, development, and technology demonstrations can be carried out and the technical assumptions can be met.
2009 MERGE Analysis
The 2009 MERGE analysis estimates the economically optimum portfolio of electricity sector technologies that will meet a CO2 emissions constraint comparable to those suggested in current policy proposals. MERGE analyzes the economywide impacts of climate policy in a global context. Under assumptions regarding CO2 emissions constraints and technology costs and availability, MERGE compares economic consequences of different technology scenarios.
The 2009 MERGE analysis compares two technology scenarios: “limited portfolio” and “full portfolio.” These two contrasting scenarios allow an assessment of the value of investing in RD&D. The limited portfolio assumes that CCS is not successfully deployed, and no expansion of the nuclear fleet. The full portfolio assumes availability of CCS, advanced nuclear (64 GWe New Build by 2030), significant improvement in costs of renewables (15% of Generation by 2030), availability of plug-in hybrid electric vehicles (PHEVs) to 100 Million PHEVs and 3x increase in non-road use by 2030, and accelerated improvements in end-use efficiency. The 2009 analysis adds several features to previous EPRI analyses:
· Emissions constraints indicative of current U.S. and international policy proposals (80% below 2005 levels for developed countries);
· Updated technology costs based on EPRI’s Technical Assessment Guide;
· Unconventional resources such as shale gas factored into natural gas supply;
· CCS retrofit for up to 60 GW of existing coal plants;
· Grid integration costs considered for high levels of variable output generation from renewables; and
· Higher biomass feedstock costs for large-scale biofuels and/or biomass electricity production.
Projected Costs Full vs Limited Portfolios
If expended today these costs would represent an average of about $16,000 per household in the full portfolio scenario compared to $28,400 in a limited portfolio that excludes new nuclear generation or carbon capture and storage.
The institute in 2007 published its first Prism and MERGE analyses, which laid out the U.S. electricity sector's potential for reducing CO2 emissions and an economically optimum technology portfolio that could meet demand growth and carbon emissions constraints. This 2009 research is based on reducing carbon emissions targets by 80 percent by 2050, consideration of new technology options, and inclusion of recent advances in technology and cost projections that take into account the impact of the current global economy.
Summary & Conclusions
According to EPRI, the 2009 Prism analysis estimates that the technical potential exists for the U.S. electricity sector to reduce annual CO2 emissions in 2030 by:
· 41% relative to 2005 emissions, based on improvements to electric sector technologies;
· 58% relative to 2005 emissions, if reductions due to electrotechnologies and electric transportation are included; and
· 62% relative to the 2030 reference case projection in the Energy Information Administration’s 2009 Annual Energy Outlook.
The 2009 Prism and MERGE analyses underscore the importance of research, development, and demonstration leading to a full portfolio of electricity sector technologies. No one technology can do the job; the full portfolio of technologies is required.
The full portfolio comprises both supply- and demand-side technologies: end-use efficiency and plug-in hybrid electric vehicles supported by a smart grid; wind, biomass, solar, advanced nuclear, and coal with CO2 capture and storage.
The MERGE analysis indicates that a technology portfolio similar to that outlined by the Prism can achieve CO2 emissions reductions at a considerably lower economic cost—as much as $1 trillion in some scenarios. Much of the required technology is not yet available, and substantial, sustained research, development and demonstration is required. Low-carbon electricity technologies drive growth in electricity demand even as CO2 emissions are reduced.
For further details on EPRI’s Prism/MERGE 2009 Update Report, see the following sources:
- Electric Power Research Institute (EPRI) http://my.epri.com/
- EPRI PRISM/MERGE Analyses - 2009 Update [EPRI Report 1019563], August 2009.
This article was partially excerpted from publically available information, and was authored by Rick Wilson, Acacia Environmental Group LLC. Any opinions expressed in this article are those solely of the author, and are not intended as legal or professional guidance to any specific readers. For more information on the author see here.
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