ECONOMICAL EVALUATION AND POTENTIAL ENVIRONMENTAL EFFECTS OF HYDROKINETIC ENERGY TECHNOLOGIES

2015 ◽  
Author(s):  
Inga ADAMONYTĖ ◽  
Algis KVARACIEJUS ◽  
Gitana VYČIENĖ
Keyword(s):  
Electricity Market ◽  
Power Plants ◽  
Aquatic Vegetation ◽  
Net Present Value ◽  
Present Value ◽  
Hydrokinetic Energy ◽  
Energy Technologies ◽  
Economical Evaluation ◽  
The Impact ◽  
Very High

An analysis of the impact of hydrokinetic energy technology schemes has been carried out on the following river parameters: water quality, the riverbed and bank stability, sediment dynamics, coastal and aquatic vegetation, fish communities, noise, aesthetics, fishing and riverbed practicability (kayaks and barges). Hydrokinetic energy generation technologies are compared to conventional tidal technologies. Each parameter assessed was evaluated for minor, notable, high, and very high likelihood of constant and temporary exposure. Subordinate elements, such as aesthetics, fishing, and river practicability were determined to be the greatest possible use of hydrokinetic energy schemes in the world rather than river ecosystem elements. The researchers carried out an approximate assessment of the economic indicators because Lithuania does not operate hydrokinetic power plants. An assessment of reduced investment and electricity market energy purchase price indicates that the approximate payback period is six years and the net present value in the seventh year of operation is EUR 7,450.

scholarly journals A Hybrid Energy System Workflow for Energy Portfolio Optimization

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4392
Author(s):  
Jia Zhou ◽  
Hany Abdel-Khalik ◽  
Paul Talbot ◽  
Cristian Rabiti
Keyword(s):  
Time Series ◽  
Gaussian Process ◽  
Electricity Market ◽  
Process Model ◽  
Net Present Value ◽  
Historical Data ◽  
Energy System ◽  
Initial Guess ◽  
Reduced Order ◽  
The Impact

This manuscript develops a workflow, driven by data analytics algorithms, to support the optimization of the economic performance of an Integrated Energy System. The goal is to determine the optimum mix of capacities from a set of different energy producers (e.g., nuclear, gas, wind and solar). A stochastic-based optimizer is employed, based on Gaussian Process Modeling, which requires numerous samples for its training. Each sample represents a time series describing the demand, load, or other operational and economic profiles for various types of energy producers. These samples are synthetically generated using a reduced order modeling algorithm that reads a limited set of historical data, such as demand and load data from past years. Numerous data analysis methods are employed to construct the reduced order models, including, for example, the Auto Regressive Moving Average, Fourier series decomposition, and the peak detection algorithm. All these algorithms are designed to detrend the data and extract features that can be employed to generate synthetic time histories that preserve the statistical properties of the original limited historical data. The optimization cost function is based on an economic model that assesses the effective cost of energy based on two figures of merit: the specific cash flow stream for each energy producer and the total Net Present Value. An initial guess for the optimal capacities is obtained using the screening curve method. The results of the Gaussian Process model-based optimization are assessed using an exhaustive Monte Carlo search, with the results indicating reasonable optimization results. The workflow has been implemented inside the Idaho National Laboratory’s Risk Analysis and Virtual Environment (RAVEN) framework. The main contribution of this study addresses several challenges in the current optimization methods of the energy portfolios in IES: First, the feasibility of generating the synthetic time series of the periodic peak data; Second, the computational burden of the conventional stochastic optimization of the energy portfolio, associated with the need for repeated executions of system models; Third, the inadequacies of previous studies in terms of the comparisons of the impact of the economic parameters. The proposed workflow can provide a scientifically defendable strategy to support decision-making in the electricity market and to help energy distributors develop a better understanding of the performance of integrated energy systems.

scholarly journals Gas to Liquids Techno-Economics of Associated Natural Gas, Bio Gas, and Landfill Gas

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1568
Author(s):  
Federico Galli ◽  
Jun-Jie Lai ◽  
Jacopo De Tommaso ◽  
Gianluca Pauletto ◽  
Gregory S. Patience
Keyword(s):  
Natural Gas ◽  
Net Present Value ◽  
Landfill Gas ◽  
Labor Cost ◽  
Variable Cost ◽  
Selling Price ◽  
Present Value ◽  
Fischer Tropsch ◽  
Gas To Liquids ◽  
The Impact

Methane is the second highest contributor to the greenhouse effect. Its global warming potential is 37 times that of CO2. Flaring-associated natural gas from remote oil reservoirs is currently the only economical alternative. Gas-to-liquid (GtL) technologies first convert natural gas into syngas, then it into liquids such as methanol, Fischer–Tropsch fuels or dimethyl ether. However, studies on the influence of feedstock composition are sparse, which also poses technical design challenges. Here, we examine the techno-economic analysis of a micro-refinery unit (MRU) that partially oxidizes methane-rich feedstocks and polymerizes the syngas formed via Fischer–Tropsch reaction. We consider three methane-containing waste gases: natural gas, biogas, and landfill gas. The FT fuel selling price is critical for the economy of the unit. A Monte Carlo simulation assesses the influence of the composition on the final product quantity as well as on the capital and operative expenses. The Aspen Plus simulation and Python calculate the net present value and payback time of the MRU for different price scenarios. The CO2 content in biogas and landfill gas limit the CO/H2 ratio to 1.3 and 0.9, respectively, which increases the olefins content of the final product. Compressors are the main source of capital cost while the labor cost represents 20–25% of the variable cost. An analysis of the impact of the plant dimension demonstrated that the higher number represents a favorable business model for this unit. A minimal production of 7,300,000 kg y−1 is required for MRU to have a positive net present value after 10 years when natural gas is the feedstock.

scholarly journals An Analysis of the Effectiveness of Two Rainwater Harvesting Systems Located in Central Eastern Europe

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 458 ◽  
Author(s):  
Agnieszka Stec ◽  
Martina Zeleňáková
Keyword(s):  
Sensitivity Analysis ◽  
Net Present Value ◽  
Rainwater Harvesting ◽  
Payback Period ◽  
Practical Aspect ◽  
Financial Ratios ◽  
Present Value ◽  
Toilet Flushing ◽  
Harvesting Systems ◽  
The Impact

Decentralized water systems are perceived as solutions that not only save water, but also as a way to partially or completely become independent from centralized suppliers. Taking this into account, an analysis of the effectiveness of rainwater harvesting systems (RWHS) for toilet flushing in existing academic facilities located in Poland and in Slovakia was carried out. The tests took into account the different volumes of storage tanks collecting rainwater. On the basis of two financial ratios, namely Net Present Value and Discounted Payback Period, the profitability of these systems was also assessed. The research was extended by the sensitivity analysis, which allowed determination of the impact of changes in individual cost components on the financial effectiveness of the investments considered. The results obtained clearly showed that the implementation of RWHS in the dormitory in Rzeszów was unprofitable for all tank capacities tested, and the payback period significantly exceeded the period of 30 years accepted for the analysis. Completely different results were obtained for RWHS in a dormitory located in the city of Košice, for which the financial ratios NPV (Net Present Value) and DPP (Discounted Payback Period) were very favorable. It was also confirmed by the results of the sensitivity analysis. The use of rainwater for toilet flushing caused that it was possible to achieve water savings of an average of 29% and 18%, respectively, for facilities located in Slovakia and Poland. The results of the research have a practical aspect and can provide an indication for potential investors and managers of academic facilities, similar to those analyzed in the article. Taking into account that in many countries water and sewage rates are significantly higher than in Poland and Slovakia, the cost-effectiveness of using the analyzed installation options in these countries could be even higher.

scholarly journals Effects of a Delayed Expansion of Interconnector Capacities in a High RES-E European Electricity System

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3098
Author(s):  
Ritter ◽  
Meyer ◽  
Koch ◽  
Haller ◽  
Bauknecht ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Electricity Market ◽  
Electricity Generation ◽  
Power Plants ◽  
Energy Transition ◽  
Market Model ◽  
Electricity Trading ◽  
Electricity System ◽  
System A ◽  
The Impact

In order to achieve a high renewable share in the electricity system, a significant expansion of cross-border exchange capacities is planned. Historically, the actual expansion of interconnector capacities has significantly lagged behind the planned expansion. This study examines the impact that such continued delays would have when compared to a strong interconnector expansion in an ambitious energy transition scenario. For this purpose, scenarios for the years 2030, 2040, and 2050 are examined using the electricity market model PowerFlex EU. The analysis reveals that both CO2 emissions and variable costs of electricity generation increase if interconnector expansion is delayed. This effect is most significant in the scenario year 2050, where lower connectivity leads roughly to a doubling of both CO2 emissions and variable costs of electricity generation. This increase results from a lower level of European electricity trading, a curtailment of electricity from a renewable energy source (RES-E), and a corresponding higher level of conventional electricity generation. Most notably, in Southern and Central Europe, less interconnection leads to higher use of natural gas power plants since less renewable electricity from Northern Europe can be integrated into the European grid.

Economic Evaluation of Proactive Replacement of Upper Internals Guide Tube Support Pins (Split Pins)

2005 ◽  
Author(s):  
Robert K. Perdue ◽  
G. Gary Elder ◽  
Gregory Gerzen
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Net Present Value ◽  
Time To Failure ◽  
Guide Tube ◽  
Reliability Modeling ◽  
Nuclear Plants ◽  
Zinc Addition ◽  
Primary Water ◽  
The Impact

Certain nuclear power plants have “Rev B” reactor vessel upper internals guide tube support pins, commonly referred to as split pins, made from material with properties similar to Alloy 600 and known to be susceptible to primary water stress corrosion cracking (PWSCC). This paper describes a rigorous probabilistic methodology for evaluating the economics of a preemptive replacement of these split pins, and describes an application at four of Exelon Generation’s nuclear plants. The method uses Bayesian statistical reliability modeling to estimate a Weibull time-to-failure prediction model using limited historical failures, and a Westinghouse proactive aging management simulation tool called PAM to select a split pin replacement date that would maximize the net present value of cash flow to a plant. Also in this study is a sensitivity evaluation of the impact of zinc addition on split pin replacement timing. Plant decisions made based in part on results derived from applying this approach are noted.

A dynamic programming algorithm for optimization of uneven-aged forest stands

1994 ◽  
Vol 24 (9) ◽  
pp. 1758-1765 ◽  
Author(s):  
David J. Anderson ◽  
B. Bruce Bare
Keyword(s):  
Dynamic Programming ◽  
Interest Rates ◽  
Net Present Value ◽  
Initial Conditions ◽  
Dynamic Programming Algorithm ◽  
Basal Area ◽  
Management Problem ◽  
Present Value ◽  
Stand Management ◽  
The Impact

A deterministic dynamic programming formulation of the transition uneven-aged stand management problem is presented. Using a previously published northern hardwoods growth model, a forward recursive, discrete, two-state problem that maximizes the net present value of harvested trees at each stage is developed. State variables represent the total number of trees and the total basal area per acre. A neighborhood storage concept previously published is used to reduce the number of states considered at each stage. Two harvest allocation rules are used to assign the harvested basal area to individual diameter classes. Terminal end point conditions and stage to stage sustainability are not required. Results from four base runs of the model are presented and compared with previously published results. Each run produces significantly different optimal paths, with one showing a higher net present value than any previously published. Sensitivity runs illustrate the impact of changes in interest rates, width of neighborhood storage class, and initial conditions. Dynamic programming offers promise for analyzing uneven-aged stand management problems.

scholarly journals Assessment of the Nutritional Impact of Agricultural Research: The Case of Mungbean in Pakistan

2005 ◽  
Vol 26 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Katinka Weinberger
Keyword(s):  
Net Present Value ◽  
Agricultural Research ◽  
Low Cost ◽  
Secondary Data ◽  
Marginal Effect ◽  
Micronutrient Deficiencies ◽  
Iron Intake ◽  
Present Value ◽  
Piece Rate ◽  
The Impact

Background Evaluation of agricultural research often neglects consumption and nutrition aspects. Yet agricultural research can address micronutrient malnutrition by improving both quantity and quality of food intake. Objective To briefly review the conceptual linkages between agriculture and nutrition, to estimate the strength of the relationship between iron intake and productivity outcomes, and to estimate the nutritional benefit of improved mungbean varieties in terms of net present value. This paper presents a methodology for assessing the nutritional impact of mungbean, and summarizes current impact evidence on the path from mungbean research to consumption. Methods A consumption study was conducted among female piece-rate workers in Pakistan to analyze the impact of iron consumption on productivity, measured in wages. A two-stage least-squares analysis was used to estimate the elasticity of iron intake on wages. The results derived from this study were extrapolated to country level using secondary data sources. Results We found that anemia among women was widespread. Approximately two-thirds of women suffered from mild or severe anemia (Hb < 12 g/dL). We found the elasticity of bioavailable iron on productivity measured in wages was 0.056, and the marginal effect was 9.17 Pakistani rupees per additional mg of bioavailable iron consumed. Using the model results we estimated the impact of mungbean research on nutrition, in terms of productivity effects, and found it was substantial, ranging from US$7.6 to 10.1 million cumulative present value (in 1995 US$ at 5% discount rate). Conclusions Agriculture certainly plays an important role in the reduction of malnutrition. Agricultural research has greatly contributed to the reduction of hunger and starvation by providing millions of hungry people with access to low-cost staple foods. Now, as the challenge shifts to the reduction of micronutrient deficiencies, more efforts must be directed toward crops high in micronutrients, such as pulses and vegetables.

SYLVER: Modelling the Impact of Silviculture on Yield, Lumber Value, and Economic Return

1988 ◽  
Vol 64 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Kenneth J. Mitchell
Keyword(s):  
Net Present Value ◽  
Financial Analysis ◽  
Wood Properties ◽  
Growth And Yield ◽  
Present Value ◽  
Silvicultural Treatments ◽  
Intensive Forest Management ◽  
Product Value ◽  
Analysis System ◽  
The Impact

Intensive forest management requires an understanding of the effect that silvicultural treatments have on wood properties, standing yield, log quality, product value, and net present value. These needs are addressed by a system of models (SYLVER) which includes the Tree and Stand Simulator (TASS), Root Rot Simulator (ROTSIM), Sawmill Simulator (SAWSIM), and the new Financial Analysis System (FAN$Y). The latter will be used by field foresters to compare the merits of candidate treatments for specific stands. Key words: Silviculture, growth and yield, juvenile wood, log quality, end-product value, net present value, Pseudotsuga menziesii, Phellinus weirii, modelling, TASS, ROTSIM, SAWSIM, FAN$Y, SYLVER.

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