100 research outputs found
Composition of electricity generation portfolios, pivotal dynamics and market prices
No full textWe use a simulation model to study how the diversification of electricity generation portfolios influences wholesale prices. We find that technological diversification generally leads to lower market prices but that the relationship is mediated by the supply to demand ratio. In each demand case there is a threshold where pivotal dynamics change. Pivotal dynamics pre- and post-threshold are the cause of non-linearities in the influence of diversification on market prices. The findings are robust to our choice of behavioural parameters and match close-form solutions where those are available.Electricity, market power, simulations, technology diversification
Spatial variation of emissions impacts due to renewable energy siting decisions in the Western U.S. under high-renewable penetration scenarios
No full textOne of the policy goals motivating programs to increase renewable energy investment is that renewable electric generation will help reduce emissions of CO(2) as well as emissions of conventional pollutants (e.g., SO(2) and NO(x)). As a policy instrument, Renewable Portfolio Standards (RPS) encourage investments in wind, solar and other generation sources with the goal of reducing air emissions from electricity production. Increased electricity production from wind turbines is expected to displace electricity production from fossil-fired plants, thus reducing overall system emissions. We analyze the emissions impacts of incremental investments in utility-scale wind power, on the order of 1 GW beyond RPS goals, in the Western United States using a utility-scale generation dispatch model that incorporates the impacts of transmission constraints. We find that wind investment in some locations leads to slight increases in overall emissions of CO(2), SO(2) and NO(x). The location of wind farms influences the environmental impact by changing the utilization of transmission assets, which affects the overall utilization of power generation sources and thus system-level emissions. Our results suggest that renewable energy policy beyond RPS targets should be carefully crafted to ensure consistency with environmental goals. (C) 2011 Published by Elsevier Ltd.Energy & FuelsEnvironmental SciencesEnvironmental StudiesSCI(E)EISSCI0ARTICLE116962-69713
Should Natural Gas Be Shipped or Stored to Supply Power Plants?
No full textFollowing a series of winters featuring extreme cold episodes in the Northeastern U.S., power grid operators have engaged in exercises focused on assessing fuel deliverability to power plants, particularly natural gas. These studies have raised important issues and identified possible scenarios that could contribute to reliability problems during winter peaks, but have not evaluated the economics of specific solutions to winter-time fuel deliverability. This paper describes an expansion to a new modeling framework for gas and electric power transmission planning problems (the Combined Electricity and Gas Expansion, or CEGE model) that allows centralized or distributed natural gas storage to be evaluated alongside traditional planning alternatives such as transmission network expansion. Using a test system based on the gas and electric transmission topology in New England, we develop a a simple two-period gas storage model and use this model to evaluate economically valuable locations for distributed natural gas storage and compare the economic merits of increasing storage within New England versus expanding pipeline infrastructure to increase fuel deliverability to New England power plants within our test system. Initial simulations using this storage model suggest that the optimal placement for gas storage may be co-located with power plants to relieve binding pressure constraints in areas of the gas network close to gas-fired generation. Moreover, the economic consequences of extreme winter peak scenarios may be ameliorated at a lower cost with a mix of gas storage and pipeline expansions rather than via pipeline expansion alone
Impacts of the retirement of the Beaver Valley and Three Mile Island nuclear power plants on capacity and energy prices in Pennsylvania
No full textValuing Technological Flexibility in Low Carbon Electricity Portfolios
No full textWith the increased focus on responding to climate change by accelerating a transition to a low carbon energy system, differing views remain on the combination of energy technologies that will best achieve this goal. Identifying technological pathways is complicated by wide uncertainties in economic and technological factors. Analyses that neglect these uncertainties can produce pathways for a low carbon energy future that are highly granular and specific, but which are based on a particular assumption about future conditions and imply a need to make specific technology commitments over a long period of time. We frame the energy transition problem as the identification of one near-term investment strategy that is flexible across a wide range of possible future costs, followed by many alternative subsequent investment plans, each of which responds to realized future costs to achieve an aggressive emissions reduction target. Using an example of planning a low carbon power system under uncertainty, we demonstrate the option value of not ruling out some energy technologies in the near-term
Valuing Technological Flexibility in Low Carbon Electricity Portfolios
No full textWith the increased focus on responding to climate change by accelerating a transition to a low carbon energy system, differing views remain on the combination of energy technologies that will best achieve this goal. Identifying technological pathways is complicated by wide uncertainties in economic and technological factors. Analyses that neglect these uncertainties can produce pathways for a low carbon energy future that are highly granular and specific, but which are based on a particular assumption about future conditions and imply a need to make specific technology commitments over a long period of time. We frame the energy transition problem as the identification of one near-term investment strategy that is flexible across a wide range of possible future costs, followed by many alternative subsequent investment plans, each of which responds to realized future costs to achieve an aggressive emissions reduction target. Using an example of planning a low carbon power system under uncertainty, we demonstrate the option value of not ruling out some energy technologies in the near-term
Strengthening the Security of Electric Power Systems during the Energy Transition: Predicting Cascading Failures and Reinforcing the Network Topology
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