The Experts below are selected from a list of 156792 Experts worldwide ranked by ideXlab platform
Ahmad Faruqui - One of the best experts on this subject based on the ideXlab platform.
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quantifying Net Energy metering subsidies
The Electricity Journal, 2019Co-Authors: Sanem Sergici, Yingxia Yang, Maria Castaner, Ahmad FaruquiAbstract:Abstract Net Energy metering (NEM) is the policy available in many states that promotes customer-owned rooftop solar power generation by compensating rooftop solar owners for each kWh that it generates at the retail rates. To help understand the magnitude of the residential Net metering subsidies, we conducted a study to assess the subsidies for 16 US utilities with varying geographic location, size, rooftop solar peNetration, and NEM policy.
Amit Kumar - One of the best experts on this subject based on the ideXlab platform.
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development of Net Energy ratios and life cycle greenhouse gas emissions of large scale mechanical Energy storage systems
Energy, 2019Co-Authors: S Kapila, Abayomi Olufemi Oni, Eskinder Demisse Gemechu, Amit KumarAbstract:Abstract In this study, a process model was developed to determine the Net Energy ratios and life cycle greenhouse gas emissions of three Energy storage systems: adiabatic and conventional compressed air Energy storage and pumped hydroelectric Energy storage, with estimated capacities of 118, 81, and 60 MW, respectively. The Net Energy ratios were calculated as ratios of Net Energy outputs to the total Net Energy inputs. The greenhouse gas emissions associated with construction, operation, decommissioning life cycle stages of the Energy storage systems were evaluated. The Net Energy ratios for the adiabatic and conventional compressed air Energy storage and pumped hydroelectric Energy storage are 0.702, 0.542, and 0.778, respectively. The respective life cycle greenhouse gas emissions in g CO2 eq./kWh are 231.2, 368.2, and 211.1. The emissions are highly dominated by the operational stage in all the Energy storage systems. It was also observed that Energy consumption in the form of electricity is the key driver, while the contributions due to the use of material are minimal. Sensitivity and uncertainty analysis was also performed. The results help in understanding the comparative Net Energy ratios and emission footprints of various Energy storage systems in order to make an informed decision.
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Comparative Net Energy ratio analysis of pellet produced from steam pretreated biomass from agricultural residues and Energy crops
Biomass and Bioenergy, 2016Co-Authors: Hassan Shahrukh, Amit Kumar, Adetoyese Olajire Oyedun, Bahman Ghiasi, Linoj Kumar, Shahab SokhansanjAbstract:Abstract A process model was developed to determine the Net Energy ratio (NER) for the production of pellets from steam pretreated agricultural residue (wheat straw) and Energy crops (i.e., switchgrass in this case). The NER is a ratio of the Net Energy output to the total Net Energy input from non-renewable Energy sources into a system. Scenarios were developed to measure the effects of temperature and level of steam pretreatment on the NER of steam pretreated wheat straw and switchgrass pellets. The NERs for the base case at 6 kg h −1 are 1.76 and 1.37 for steam-pretreated wheat straw and switchgrass-based pellets, respectively. The reason behind the difference is that more Energy is required to dry switchgrass pellets than wheat straw pellets. The sensitivity analysis for the model shows that the optimum temperature for steam pretreatment is 160 °C with 50% pretreatment (i.e. 50 % steam treated material is blended with the raw biomass and then pelletised). The uncertainty results for NER for steam pretreated wheat straw and switch grass pellets are 1.62 ± 0.10 and 1.42 ± 0.11, respectively.
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Development of Net Energy ratio and emission factor for quad-generation pathways
Energy Systems, 2014Co-Authors: Souman Rudra, Lasse Rosendahl, Amit KumarAbstract:The conversion of biomass to four different outputs via gasification is a renewable technology that could reduce the use of fossil fuels and greenhouse gas (GHG) emissions. This study investigates the Energy aspects for a new concept of biomass based quad-generation plant producing power, heat, methanol and methane. Circulating fluidized bed gasifier and the gas technology institute (GTI) gasifier technologies are used for this quad-generation process. Two different biomass feedstocks are considered in this study. The Net Energy ratio for six different pathways having the range of between 1.3 and 7.2. The lowest limit corresponds to the wood chips-based power, heat, methanol and methane production pathway using GTI technology. Since more efficient alternatives exist for the generation of heat and electricity from biomass, it is argued that syngas is best used for methanol production. The aim of this study was to evaluate the Energy performance, reduce GHG and acid rain precursor emission, and use of biomass for different outputs based on demand. Finally, a sensitivity analysis and a comparative study ar conducted for expected technological improvements and factors that could increase the Energy performance.
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development of emission parameters and Net Energy ratio for renewable diesel from canola and camelina
Energy, 2013Co-Authors: Patrick Miller, Amit KumarAbstract:This study estimated the greenhouse gas emissions (GHGs) and Net Energy ratio (NER) for producing hydrogenation-derived renewable diesel (HDRD) from canola and camelina in Western Canada. Using 1 MJ of Energy in the HDRD produced as the functional unit, a variety of scenarios were evaluated to account for variations in allocation methods, co-products, oilseed yield, N2O emission factor, and land use change (LUC). In producing HDRD, the farming stage and the oil conversion stage (i.e. the HDRD production stage) are the most Energy and emission intensive. For canola based HDRD, the GHGs and NERs lie in the ranges of 33–94 gCO2e/MJ and 1.2–2.2 MJ/MJ respectively. For camelina based HDRD, the GHGs and NERs range from 30 – 82 gCO2e/MJ and 1.0–2.3 MJ/MJ respectively. In the base scenario (mass allocation; oilseed meal and propane fuel gas co-products; average yield; 0.76% N2O emission factor; LUC ignored), HDRD from camelina (38 gCO2e/MJ, 2.0 MJ/MJ) is environmentally superior to HDRD from canola (48 gCO2e/MJ, 1.7 MJ/MJ) due to lower agricultural inputs and higher yield for camelina. Considering all of the scenarios examined, HDRD from both crops appears to be more sustainable than fossil diesel.
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development of Net Energy ratio and emission factor for biohydrogen production pathways
Bioresource Technology, 2011Co-Authors: Ruhul Kabir, Amit KumarAbstract:Abstract This study investigates the Energy and environmental aspects of producing biohydrogen for bitumen upgrading from a life cycle perspective. Three technologies are studied for biohydrogen production; these include the Battelle Columbus Laboratory (BCL) gasifier, the Gas Technology Institute (GTI) gasifier, and fast pyrolysis. Three different biomass feedstocks are considered including forest residue (FR), whole forest (WF), and agricultural residue (AR). The fast pyrolysis pathway includes two cases: truck transport of bio-oil and pipeline transport of bio-oil. The Net Energy ratios (NERs) for nine biohydrogen pathways lie in the range of 1.3–9.3. The maximum NER (9.3) is for the FR-based pathway using GTI technology. The GHG emissions lie in the range of 1.20–8.1 kg CO 2 eq/kg H 2 . The lowest limit corresponds to the FR-based biohydrogen production pathway using GTI technology. This study also analyzes the intensities for acid rain precursor and ground level ozone precursor.
Sanem Sergici - One of the best experts on this subject based on the ideXlab platform.
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quantifying Net Energy metering subsidies
The Electricity Journal, 2019Co-Authors: Sanem Sergici, Yingxia Yang, Maria Castaner, Ahmad FaruquiAbstract:Abstract Net Energy metering (NEM) is the policy available in many states that promotes customer-owned rooftop solar power generation by compensating rooftop solar owners for each kWh that it generates at the retail rates. To help understand the magnitude of the residential Net metering subsidies, we conducted a study to assess the subsidies for 16 US utilities with varying geographic location, size, rooftop solar peNetration, and NEM policy.
Jeffery B Greenblatt - One of the best experts on this subject based on the ideXlab platform.
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life cycle Net Energy assessment of large scale hydrogen production via photoelectrochemical water splitting
Energy and Environmental Science, 2014Co-Authors: Roger Sathre, Corinne D Scown, William R Morrow, John C Stevens, Ian D Sharp, J W Ager, Karl Walczak, Frances A Houle, Jeffery B GreenblattAbstract:Here we report a prospective life-cycle Net Energy assessment of a hypothetical large-scale photoelectrochemical (PEC) hydrogen production facility with Energy output equivalent to 1 GW continuous annual average (1 GW HHV = 610 metric tons of H2 per day). We determine essential mass and Energy flows based on fundamental principles, and use heuristic methods to conduct a preliminary engineering design of the facility. We then develop and apply a parametric model describing system-wide Energy flows associated with the production, utilization, and decommissioning of the facility. Based on these flows, we calculate and interpret life-cycle Net Energy metrics for the facility. We find that under base-case conditions the Energy payback time is 8.1 years, the Energy return on Energy invested (EROEI) is 1.7, and the life-cycle primary Energy balance over the 40 years projected service life of the facility is +500 PJ. The most important model parameters affecting the Net Energy metrics are the solar-to-hydrogen (STH) conversion efficiency and the life span of the PEC cells; parameters associated with the balance of systems (BOS), including construction and operation of the liquid and gas handling infrastructure, play a much smaller role.
Pei-te Chiueh - One of the best experts on this subject based on the ideXlab platform.
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Life cycle assessment and Net Energy analysis of offshore wind power systems
Renewable Energy, 2017Co-Authors: Yu-fong Huang, Xing-jia Gan, Pei-te ChiuehAbstract:Abstract This study attempted to evaluate the environmental impact and Energy benefit of offshore wind power systems using life cycle assessment (LCA) and Net Energy analysis. The environmental impact of offshore wind power systems is based primarily on ferrous metal, which is used to install the foundations, towers, and nacelles. The impact categories with the greatest relevance were fossil fuels and respiratory inorganics. This study assumed that the life cycle of an offshore wind power system has four stages (production, installation, operation and maintenance, and end-of-life). Two scenarios were examined in this study. The major difference between the scenarios was that Scenario 2 included an offshore substation. The overall environmental impact in Scenario 2 was higher than that in Scenario 1 by approximately 10%. The Net Energy analysis in this study included the evaluations of cumulative Energy demand (CED), Energy return on investment (EROI), and Energy payback time (EPT). For Scenarios 1 and 2, CED was 0.192 and 0.216 MJ/kWh, EROI was 18.7 and 16.7, and EPT was 12.8 and 14.4 months, respectively. Moreover, when the recycling of waste materials was considered, each scenario produced a 25% lower environmental impact, 30% lower Energy requirement, and 4 months lower EPT.