•Techno-economic analysis of gravity energy storage.•Energetic performance of Gravity Energy Storage (GES) with a wire rope hoisting system.•Energy storage LCOE and LCOS comparison•GES and GESH offer ...interesting economic advantages for the provision of energy arbitrage service.
Interest in energy storage systems has been increased with the growing penetration of variable renewable energy sources. This paper discusses a detailed economic analysis of an attractive gravitational potential energy storage option, known as gravity energy storage (GES). The economic performance of this energy storage system is compared to other alternative energy storage technologies such as pumped hydro energy storage (PHES) and compressed air energy storage (CAES). Moreover, a life cycle costs and levelized cost of electricity delivered by this energy storage are analyzed to provide expert, power producers, and grid operators insight about the economic implications of this grid-scale gravitational energy storage technology. Depending on the considered scenarios and assumptions, the levelized cost of storage of GES varies between 7.5 €ct/kWh and 15 €ct/kWh, while it is between 3.8 €ct/kWh and 7.3 €ct/kWh for gravity energy storage with wire hoisting system (GESH). The LCOS of GES and GESH were then compared to other energy storage systems. The obtained results show that GESH is very cost-competitive with pumped hydro and Compressed Air Energy Storage technologies; while GES is competitive with PHES and may be cost-competitive with CAES depending on the operation cycles. The performed analysis has also shown that both GES and GESH offer interesting economic advantages for the provision of energy arbitrage service.
Geothermal energy is gaining momentum as a renewable energy source. Reservoir simulation studies are often used to understand the underlying physics interactions and support decision making. ...Uncertainty related to geothermal systems can be substantial for subsurface and operational parameters and their interaction with regards to the output in terms of lifetime, energy and economic output. Specifically, for geothermal systems with the fault acting as the main fluid pathway the relevant field development uncertainties have not been comprehensively addressed. In this study we show how the produced energy, system lifetime and NPV are affected considering a range of subsurface and operational parameters as uncertainty sources utilizing an ensemble of 16,200 3D Hydraulic-Thermal (HT) reservoir simulations, conceptually based on the Rittershoffen field. A well configuration with oblique angles with respect to the main permeability anisotropy axes results in higher system lifetime, generated energy and NPV. A well spacing of 600 m consistently yields a higher economic efficiency (€/MWh) under all uncertainty parameters considered. More robust development options could be utilized in the absence of fault permeability characterization to ensure improved output prediction under uncertainty. Studies based on the methodology presented can improve investment efficiency for field development under subsurface and operational uncertainty.
•A novel combined heating and power (CHP) cycle is proposed.•Energetic, exergetic, environmental and economic analysis of cycle are sought.•Payback period and net present value methods are utilized ...for economic evaluation.•Comprehensive parametric study of some design parameters is carried out.•Energy and exergy efficiencies of system are 69.37% and 37.95% in base conditions.
This research aims at developing a small-scale novel cogeneration system to satisfy all of the electrical and heating demands of a typical residential complex. The proposed system is integrated of a gas turbine cycle (GTC) and a Kalina cycle (KC). A comprehensive parametric study is presented for evaluating the proposed system from energy, exergy, environmental and economic (4E) points of view. The system’s governing equations are solved and validated through developing a high-accuracy computational code in Engineering Equation Solver (EES) software. The effects of some important design parameters (including compressor pressure ratio, base ammonia concentration, generator pressure and condenser pinch point temperature difference) are investigated on four appropriate criteria of energy efficiency (ηth), exergy efficiency (ηex), levelized total emissions (LTE) and levelized total costs (LTC). Furthermore, two economic methods, payback period (PP) and net present value (NPV), are also investigated. The results show that, the simulation outputs at base design conditions are as ηth = 69.43%, ηex = 37.90%, LTE = 87998 kg/kW, LTC = 8958 $/kW, PP = 3.34 years and NPV = 878679 $. The results of parametric analysis reveal that there is an optimal compressor pressure ratio which leads to maximum ηth and ηex and minimum LTE and LTC. The combustion chamber of GTC has the maximum share in system’s total exergy destruction (with 55.95% of total exergy destruction). Also, the entire KC has a low contribution of 3.396% in total exergy destruction.
Feasibility analysis is done to determine a business design is feasible to run. The purpose of this research is to find out if Humblezing established an offline store branch in South Jakarta is ...feasible or not to run. Humblezing is a clothing line business that sells clothing products such as outerwear, shirts, jackets, pants, and bag with the concept of modern adventurwear. Humblezing sells online and offline with the first store in Bandung. The feasibility measurement pay attention to market aspects, technical aspects and financial aspects which will be projected for 5 years. The tools that used in this research are Net Present Value (NPV), Internal Rate of Return (IRR), Payback Period (PBP), Sensitivity Analysis and Risk Analysis. Based on the results of the feasibility analysis, show that the NPV value is IDR 185,343,832, IRR 38%, PBP for 3.81 years with a MARR value is 11,25%. Sensitivity measurements on the increase in product costs sensitive at 9.31%, increase in labor costs at 14.07%, decrease in selling prices at 3.19% and decrease in market demand at 2.33%. Furthermore, the estimated accumulated risk of establishing a Humblezing offline store branch includes market risk, operational risk and financial risk is 5.50%.
Thrombotic microangiopathies (TMA) are a group of disorders with overlapping clinical features that require urgent intervention. Treatment is based on the recognition of the TMA type, which is often ...challenging. The aim of this study was to identify specific HLA associations with different TMA types to aid rapid diagnosis and appropriate treatment, since the HLA assay can be completed within five hours.
All 86 consecutive patients who presented to the University of Arkansas for Medical Sciences between May 2013 and January 2021 with a presumptive diagnosis of TMA were included in this study. HLA typing was performed and correlated with other clinical and laboratory studies.
In comparison with other types of TMA, patients with acquired thrombotic thrombocytopenic purpura (aTTP) showed increased frequencies of HLA-DRB1*11, HLA-DQB1*03:01/19, HLA-DRB1*08 and HLA-DRB3. Combining the presence of these HLA associations with a PLASMIC score of 6 or more achieved a higher positive predictive value (90%) for identifying aTTP than the PLASMIC score alone (69%). In comparison with other TMA types, patients with aTTP showed decreased frequencies of HLA-DRB4, HLA-DRB1*07, HLA-DQB1*02. The HLA-DRB1*07/DQB1*02 was not observed in any aTTP patients (negative predictive value: 100%), and thus the presence of this haplotype essentially rules out aTTP. Further, HLA-DRB1*11/DQB1*03:01/19 was absent in atypical hemolytic uremic syndrome patients.
HLA alleles can be used as an adjunct for the rapid assessment of TMA and can help to differentiate it from other primary and secondary forms of TMA, allowing for earlier definitive therapy.
Natural gas pressure reduction station (CGS) is one of the most important pieces in natural gas transmission system. In a CGS, the high inlet natural gas (NG) pressure has to be reduced down to a ...much lower value. Pressure reduction is usually implemented by utilizing throttling valves. Due to the positive Joule–Thompson coefficient of NG, this pressure drop causes significant temperature fall and consequently hydrate forming in the NG stream. The hydrates may prevent stable NG flow through the pipeline. To prevent hydrate forming, the NG should be preheated by some heaters which burn huge amount of fuel. In this work, firstly, adding a solar heating system aiming to reduce the heater fuel consumption and secondly, replacing the throttling valve by a turbo expander in order to utilize the NG stream exergy are proposed. The proposed configuration is simulated for Birjand CGS as a case study. For the simulation, the locally available solar irradiation is estimated by employing solar engineering formulations and the NG availability is calculated by thermodynamics correlations. Net present value (NPV) method is also employed to analyze the proposed system effectiveness economically, resulting to only 3.5 years of pay back ratio.
•Two steps of modifications are proposed to be implemented on the CGS configuration.•Employing solar heating system to reduce the fuel consumption is the first proposal.•Replacing the throttling valve by a power production unit is the second proposal.•Detailed exergy and energy analysis on the proposed system is presented.•Economic analysis on the system is carried out to prove its effectiveness.
This paper emphasizes the conceptualization and techno-economic-environmental analysis of a novel power-to-heat system based on the excess energy from solar photovoltaic (PV) plants and open-loop ...geothermal heat pumps (GHPs). This integrated energy system is engineered to supply simultaneously the electric load in a residential community and the heat demand in a primary school. The solar PV plant was optimized in a way to maximize the project net present value (NPV). Environmental accounting was as well introduced by estimating the total environmental penalty cost saving (TEPCS) for various carbon prices. Several scenarios were investigated, and corresponding optimum designs were determined. For annual electric and heat demand of 207.46 MWhele and 13.67 MWhth in the residential community and the primary school, respectively, the optimum PV capacity to be installed is 26 kWp when no inflation of the grid electricity cost is considered. For this optimum PV capacity, the NPV is about 19.41 k$. The annual savings and discounted payback period for this case are calculated as 4.88 k$/year and 14.45 years, respectively. Including carbon prices enhanced the economic attractiveness of the concept. For a carbon cost of 40 $/tCO2, the recommended PV capacity is 36.4 kWp giving rise to a TCS of 33.8 k$.
Hydrocarbon production in Indonesia is continuously decreasing on a yearly basis, which is in contrast with its increasing level of consumption. Low-quality and low-resistivity reservoir zones are ...deemed to possess a lot of hydrocarbon potentials, however, little priority has been placed on their development due to their small level of production. The "RI" field that was utilized in this study is a mature offshore field with a reservoir which has a low-quality and low-resistivity zone. This area has been in use for more than thirty years, therefore its rate of oil production has declined. This study aims to review the techno-economic aspects of well stimulation in the form of hydraulic fracturing. And also, to determine the development method that is suitable for low-quality fields. The hydraulic fracturing process was modelled using Fracpro software as input parameters for the reservoir production simulations. The reservoir behavior was simulated using the CMG software to observe the amount of hydrocarbon liable for production in various development scenarios. Three cases were performed on the "RI" field, which was stimulated for ten years of operation. The first case was the instance with the natural flow, while the second implemented hydraulic fracturing at the beginning of production, and the third was the implementation of hydraulic fracturing, which started in the middle of the production period. Then, the three cases are evaluated utilizing a Gross Split scheme, to calculate the economics of the project both from the government and contractor's aspects. The simulation study concluded that fracturing at the beginning of the LRLC zone development is the most profitable. The novelty of this study is the comparison of scenarios for the implementation of hydraulic fracturing methods in fields with low-resistivity and low-quality zone whose economic value is evaluated by the Gross Split scheme.
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