Browsing by Subject "CCS"

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    DISPATCHABLE CCS - Minimizing the Energy Penalty Costs
    (2010-04-30T08:44:13Z) Neeraj, Gurpreet
    The study aims at estimating reductions in energy penalty costs of a CO2 capture plant by exploiting price volatility in the electricity markets. The policy implication of this reduced abatement cost could be an increased penetration of Carbon Capture and Storage (CCS) in the future. ‘Dispatchable CCS’ offers the plant operator the option to choose a desired CO2 capture operating condition based on current market conditions such as fuel prices, CO2 prices, and electricity prices. It looks at possible design options of this flexibility in the operation of the carbon capture plant with addition of amine storage tanks and vent out pipes. It gives us a brief outline of these flexible design options and the costs associated with them. This is followed by the calculation of Total Costs ($/ton) of CO2 capture in a Dispatchable CCS system. This task is performed at first with constant electricity prices, to stress the importance of electricity price variations on the Total Cost of the system. A parametric analysis on capture rate and electricity price is later used to calculate the NPV for the two flexible designs. The results show lower cost estimates as compared to the full loads capture system, for the two flexible designs in the study. The study looks at some other benefits arising out of a ‘Dispatchable CCS’ system. It also discusses some future considerations to further the goal of this study.
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    ItemOpen Access
    Electric Power Plant Water Use in North Carolina: Forced Evaporation and Emission Controls
    (2010-04-30T13:51:18Z) Morton, Victoria
    The link between water use and electricity generation is very strong and largely omitted from the public policies aimed at sustainable generation of electricity. Electricity is required for treating and pumping water to its destination, and water is required for electricity generation at thermoelectric power plants for cooling purposes, and for the operation of environmental control devices that reduce air emissions. North Carolina is ranked 9th in the United States for electricity total net production, according to the Energy Information Administration. Thermoelectric power freshwater withdrawals far outstrip all other water withdrawal categories; by the year 2000, thermoelectric power freshwater withdrawals were approaching 8,000 million gallons per day, and as the population continues to grow in North Carolina, that number can only be expected to increase. They make some of the largest water withdrawals in the state of North Carolina, but they only consume approximately 3% of the water they intake. The consumptive use percentage of 3% is misleading because it doesn’t take into account forced evaporation. As mentioned previously, power plants require intake water to use for cooling purposes in the electricity generation process. The withdrawn cooling waters, once run through the plant, are returned to rivers/lakes at a higher temperature than the ambient water temperature. This higher temperature water causes additional evaporation (forced evaporation) from the river/lake. Forced evaporation should be of particular concern to North Carolina due to the severe droughts that have occurred in the region in recent history which threaten energy production as well as other water uses (ex. drinking water supply). In this project we find that forced evaporation represents an average 22% increase in power plant water consumption in North Carolina, when compared to water consumption occurring during electricity generation on-site. We also look at the impact that air emission controls have on the plants water consumption. If carbon emissions are required to be controlled in the future, then water use at all power plants will increase, on average, approximately 5%. The water lost to forced evaporation and emissions controls will add additional strain to power plants located in drought prone regions.
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    Impacts of Geological Variability on Carbon Storage Potential
    (2011) Eccles, Jordan Kaelin

    The changes to the environment caused by anthropogenic climate change pose major challenges for energy production in the next century. Carbon Capture and Storage (CCS) is a group of technologies that would permit the continued use of carbon-intense fuels such as coal for energy production while avoiding further impact on the global climate system. The mechanism most often proposed for storage is injection of CO2 below the surface of the Earth in geological media, with the most promising option for CO2 reservoirs being deep saline aquifers (DSA's). Unlike oil and gas reservoirs, deep saline aquifers are poorly characterized and the variability in their properties is large enough to have a high impact on the overall physical and economic viability of CCS. Storage in saline aquifers is likely to be a very high-capacity resource, but its economic viability is almost unknown. We consider the impact of geological variability on the total viability of the CO2 storage system from several perspectives. First, we examine the theoretical range of costs of storage by coupling a physical and economic model of CO2 storage with a range of possible geological settings. With the relevant properties of rock extending over several orders of magnitude, it is not surprising that we find costs and storage potential ranging over several orders of magnitude. Second, we use georeferenced data to evaluate the spatial distribution of cost and capacity. When paired together to build a marginal abatement cost curve (MACC), this cost and capacity data indicates that low cost and high capacity are collocated; storage in these promising areas is likely to be quite viable but may not be available to all CO2 sources. However, when we continue to explore the impact of geological variability on realistic, commercial-scale site sizes by invoking capacity and pressure management constraints, we find that the distribution costs and footprints of these sites may be prohibitively high. The combination of issues with onshore storage in geological media leads us to begin to evaluate offshore storage potential. By considering the temperature and pressure regimes at the seafloor, we locate and quantify marine strata that has "self-sealing" properties, a storage option that we find is plentiful off the coasts of the United States. We conclude that further research into transport optimization that takes into account the true variation in geological media is necessary to determine the distribution of costs for carbon capture and storage to permit the full evaluation of CCS as a mitigation option.