Margaret K. Mann

Life Cycle Assessment of a Natural Gas Combined-Cycle Power Generation System

Natural gas is used for steam and heat production in industrial processes, residential and commercial heating, and electric power generation. Because of its importance in the power mix, a life cycle assessment on electricity generation via a natural gas combined cycle system has been performed.

Life cycle environmental impacts of selected U.S. ethanol production and use pathways in 2022.

Projected life cycle greenhouse gas (GHG) emissions and net energy value (NEV) of high-ethanol blend fuel (E85) used to propel a passenger car in the United States are evaluated using attributional life cycle assessment. Input data represent national-average conditions projected to 2022 for ethanol produced from corn grain, corn stover, wheat straw, switchgrass, and forest residues. Three conversion technologies are assessed: advanced dry mill (corn grain), biochemical (switchgrass, corn stover, wheat straw), and thermochemical (forest residues). A reference case is compared against results from Monte Carlo uncertainty analysis. For this case, one kilometer traveled on E85 from the feedstock-to-ethanol pathways evaluated has 43%-57% lower GHG emissions than a car operated on conventional U.S. gasoline (base year 2005). Differences in NEV cluster by conversion technology rather than by feedstock. The reference case estimates of GHG and NEV skew to the tails of the estimated frequency distributions. Though not as optimistic as the reference case, the projected median GHG and NEV for all feedstock-to-E85 pathways evaluated offer significant improvement over conventional U.S. gasoline. Sensitivity analysis suggests that inputs to the feedstock production phase are the most influential parameters for GHG and NEV. Results from this study can be used to help focus research and development efforts.

Cost and performance analysis of biomass-based integrated gasification combined-cycle (BIGCC) power systems

To make a significant contribution to the power mix in the United States biomass power systems must be competitive on a cost and efficiency basis. We describe the cost and performance of three biomass-based integrated gasification combined cycle (IGCC) systems. The economic viability and efficiency performance of the IGCC generation technology appear to be quite attractive.

Renewable Energy Sources and Climate Change Mitigation: Direct Solar Energy

Executive Summary Solar energy is abundant and offers significant potential for near-term (2020) and long-term (2050) climate change mitigation. There are a wide variety of solar technologies of varying maturities that can, in most regions of the world, contribute to a suite of energy services. Even though solar energy generation still only represents a small fraction of total energy consumption, markets for solar technologies are growing rapidly. Much of the desirability of solar technology is its inherently smaller environmental burden and the opportunity it offers for positive social impacts. The cost of solar technologies has been reduced significantly over the past 30 years and technical advances and supportive public policies continue to offer the potential for additional cost reductions. Potential deployment scenarios range widely—from a marginal role of direct solar energy in 2050 to one of the major sources of energy supply. The actual deployment achieved will depend on the degree of continued innovation, cost reductions and supportive public policies. Solar energy is the most abundant of all energy resources . Indeed, the rate at which solar energy is intercepted by the Earth is about 10,000 times greater than the rate at which humankind consumes energy. Although not all countries are equally endowed with solar energy, a significant contribution to the energy mix from direct solar energy is possible for almost every country. Currently, there is no evidence indicating a substantial impact of climate change on regional solar resources.

Economic and life cycle assessment of an integrated biomass gasification combined cycle system

When life cycle assessment is performed in conjunction with a technoeconomic feasibility study, the total economic and environmental benefits and drawbacks of a process can be quantified. A biomass gasification combined-cycle power plant consisting of a low pressure indirectly-heated gasifier integrated with an industrial gas turbine was simulated using ASPEN Plus(R) and economic analyses were performed to determine the levelized cost of electricity. To complement this study, a life cycle assessment is being performed. The processes considered in the overall analysis consist of the production of biomass as a dedicated feedstock crop, its transportation to the power plant electricity generation, and all processes associated with intermediate feedstocks. The primary goal of this life cycle assessment is to reduce the environmental impact of the system through design improvements. For the purpose of this study, life cycle assessment is defined as a systematic method for identifying, evaluating, and minimizing the environmental impacts of emissions and resource depletion associated with this specific process. A discussion of the economics, efficiency, and methodology for assessing environmental benefits of power production from this biomass-based technology, are presented.

Life Cycle Assessment of the Energy Independence and Security Act of 2007: Ethanol - Global Warming Potential and Environmental Emissions

The objective of this study is to use life cycle assessment (LCA) to evaluate the global warming potential (GWP), water use, and net energy value (NEV) associated with the EISA-mandated 16 bgy cellulosic biofuels target, which is assumed in this study to be met by cellulosic-based ethanol, and the EISA-mandated 15 bgy conventional corn ethanol target. Specifically, this study compares, on a per-kilometer-driven basis, the GWP, water use, and NEV for the year 2022 for several biomass feedstocks.

Chapter 13: Prospects for Renewable Energy

Publisher Summary This chapter examines availability, markets, and the technical potential of renewable energy (RE) resources in meeting energy demand in a redefined energy economy. These new energy challenges include energy security, environmental integrity, climate change, and economic prosperity. It looks at how far renewables have come during the past decades and their potential to provide a larger portion of energy needs in the future. It also examines the current status of renewables capacity as well as technology investment; it includes trends by country and by technology as well as the impact of the global economic situation. Market and technology trends for resources such as hydropower, wind, solar, geothermal, and bioenergy; it also provides market projections are also outlined.

Global Value Chain and Manufacturing Analysis on Geothermal Power Plant Turbines

The global geothermal electricity market has significantly grown over the last decade and is expected to reach a total installed capacity of 18.4 GWe in 2021 (GEA, 2016). Currently, geothermal project developers customize the size of the power plant to fit the resource being developed. In particular, the turbine is designed and sized to optimize efficiency and resource utilization for electricity production; most often, other power plant components are then chosen to complement the turbine design. These custom turbine designs demand one-off manufacturing processes, which result in higher manufacturing setup costs, longer lead-times, and higher capital costs overall in comparison to largervolume line manufacturing processes. In contrast, turbines produced in standard increments, manufactured in larger volumes, could result in lower costs per turbine. This study focuses on analysis of the global supply chain and manufacturing costs for Organic Rankine Cycle (ORC) turboexpanders and steam turbines used in geothermal power plants. In this study, we developed a manufacturing cost model to identify requirements for equipment, facilities, raw materials, and labor. We analyzed three different cases 1) 1 MWe geothermal ORC turboexpander 2) 5 MWe ORC turboexpander and 3) 20 MWe geothermal steam turbine, and calculated the cost of manufacturing the major components, such as the impellers/blades, shaft/rotor, nozzles, inlet guide lanes, disks, and casings. Then we used discounted cash flow (DCF) analysis to calculate the minimum sustainable price (MSP). MSP is the minimum price that a company must sell its product for in order to pay back the capital and operating expenses during the plant lifetime (CEMAC, 2017). The results showed that MSP could highly vary between 893

Regional Manufacturing Cost Structures and Supply Chain Considerations for SiC Power Electronics in Medium Voltage Motor Drives

/kW and 30

Multi-Metric Sustainability Analysis

/kW based on turbine size, standardization and volume of manufacturing. The analysis also showed that the economy of scale applies both to the size of the turbine and the number manufactured in a single run. Sensitivity analysis indicated these savings come largely from reduced labor costs for design and engineering and manufacturing setup.