scholarly journals Use of Optimization Modeling to Assess the Effect of Timber and Carbon Pricing on Harvest Scheduling, Carbon Sequestration, and Net Present Value of Eucalyptus Plantations

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 651
Author(s):  
Andrés Hirigoyen ◽  
Mauricio Acuna ◽  
Cecilia Rachid-Casnati ◽  
Jorge Franco ◽  
Rafael Navarro-Cerrillo
Keyword(s):  
Net Present Value ◽  
Programming Model ◽  
C Sequestration ◽  
Mixed Integer ◽  
Harvest Scheduling ◽  
Economic Returns ◽  
Present Value ◽  
Planning Period ◽  
Eucalyptus Dunnii ◽  
The Impact

Quantifying the impact of carbon (C) and timber prices on harvest scheduling and economic returns is essential to define strategies for the sustainable management of short-rotation plantations so that they can provide timber products and contribute to C sequestration. In this paper, we present a mixed-integer linear programming model that optimizes harvest scheduling at the forest level, C sequestration, and Net Present Value (NPV) over a planning period of up to 15 years. The model included revenue from the sale of timber (pulplogs) and credits from the net C sequestered during the life of the stands. In addition, plantation establishment, management, harvesting, and transportation costs were included in the analysis. The study area comprised 88 Eucalyptus grandis W. Hill and Eucalyptus dunnii Maiden stands located in Uruguay, totaling a forest area of nearly 1,882 ha. The study investigated the impact of C and timber prices on NPV, harvest schedules, stands’ harvest age, timber flows to customers, and C sequestered per period. The maximum NPV among all the scenarios evaluated (USD 7.53 M) was calculated for a C price of 30 USD t−1, an interest rate of 6%, and a timber price of 75 USD m−3. This was USD 2.14 M higher than the scenario with the same parameters but that included only revenue from timber. C prices also impacted stands’ harvest age, C sequestration, and timber flows delivered to end customers. On average, in scenarios that included C prices, timber flows and C sequestration increased by 15.4 and 12.1%, respectively, when C price increased from 5 to 30 USD t−1. These results demonstrate that harvest scheduling, harvest age, and NPV are very sensitive to C and timber, and that the best economic returns are obtained when the stands are managed to maximize timber production and C sequestration.

scholarly journals An Application of Linear Programming for Short-Term Harvest Scheduling

1988 ◽  
Vol 5 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Douglas C. Macmillan ◽  
Stephen E. Fairweather
Keyword(s):  
Linear Programming ◽  
Net Present Value ◽  
Harvest Scheduling ◽  
Present Value ◽  
Short Term ◽  
Planning Period ◽  
Additional Information ◽  
Forest Ownership ◽  
Forest Enterprises ◽  
High Level

Abstract The technique of linear programming (LP) is illustrated by developing a harvest schedule for an industrial forest ownership in northwestern Pennsylvania. The objective was to maximize net present value of the harvest over a five-year planning period. The effect of changes in timber value and growth rate on the optimum schedule was determined. Sensitivity analysis provided additional information the manager could use to make decisions. In order to successfully apply LP, the forester must be able to define the management objective of the harvest schedule and the resource and managerial constraints that will influence its attainment. Data used in the model have to be available and reliable. Many forest enterprises should be in the position to adopt LP since commercial programs for microcomputers are now available for which a high level of computing expertise is not required. North. J. Appl. For. 5:145-148, June 1988.

A Decision Advisor to Manage the Implications of Alloy 600 Issues

2003 ◽  
Author(s):  
R. K. Perdue ◽  
C. W. Mycoff ◽  
J. Woodcock ◽  
T. A. Meyer ◽  
R. Llovet
Keyword(s):  
Crack Propagation ◽  
Net Present Value ◽  
Computer Software ◽  
Alloy 600 ◽  
Present Value ◽  
Planning Period ◽  
Software Model ◽  
Plant Operations ◽  
Plant Level ◽  
The Impact

A Decision Advisor process has been designed to efficiently support plant level decisions, and the process has been specialized to support decisions pertaining to plant locations that have alloy 600 degradation issues. The process guides the decision maker through phases of framing the problem, developing options, selecting alternatives, and planning. The decision making process is supported by a computer software model that quantifies the net present value costs of each identified strategy. The Alloy 600 Decision Advisor model calculates crack initiation and growth and the impact on operations and revenue for a given inspection and repair strategy. The three major modules in a component Decision Advisor are: engineering issues of crack propagation and detection, plant operations, and financial impacts. The crack propagation and detection module captures the current state-of-the-art knowledge regarding alloy 600 (and alloy 182/82 for welds) degradation, combining statistical analysis of historical data and expert engineering judgment to produce a forecast of cracks and leaks over the relevant planning period. This is input to the plant operational impact module, which calculates the resulting impacts on plant revenue and cost drivers. The model can be readily updated as new information (such as inspection results) comes available. Results are provided in a report describing the goals and objectives together with the technical and financial input, and providing the plant-level net present value cost of each alternative. The net present value costs include typical costs of implementation (such as inspections and repairs) as well as the effects on power production and plant revenue.

scholarly journals Efficient Operative Cost Reduction in Distribution Grids Considering the Optimal Placement and Sizing of D-STATCOMs Using a Discrete-Continuous VSA

2021 ◽  
Vol 11 (5) ◽  
pp. 2175
Author(s):  
Oscar Danilo Montoya ◽  
Walter Gil-González ◽  
Jesus C. Hernández
Keyword(s):  
Objective Function ◽  
Reactive Power ◽  
Programming Model ◽  
Search Algorithm ◽  
Solution Space ◽  
Distribution Networks ◽  
Optimal Placement ◽  
Mixed Integer ◽  
Solution Vector ◽  
The Impact

The problem of reactive power compensation in electric distribution networks is addressed in this research paper from the point of view of the combinatorial optimization using a new discrete-continuous version of the vortex search algorithm (DCVSA). To explore and exploit the solution space, a discrete-continuous codification of the solution vector is proposed, where the discrete part determines the nodes where the distribution static compensator (D-STATCOM) will be installed, and the continuous part of the codification determines the optimal sizes of the D-STATCOMs. The main advantage of such codification is that the mixed-integer nonlinear programming model (MINLP) that represents the problem of optimal placement and sizing of the D-STATCOMs in distribution networks only requires a classical power flow method to evaluate the objective function, which implies that it can be implemented in any programming language. The objective function is the total costs of the grid power losses and the annualized investment costs in D-STATCOMs. In addition, to include the impact of the daily load variations, the active and reactive power demand curves are included in the optimization model. Numerical results in two radial test feeders with 33 and 69 buses demonstrate that the proposed DCVSA can solve the MINLP model with best results when compared with the MINLP solvers available in the GAMS software. All the simulations are implemented in MATLAB software using its programming environment.

scholarly journals A Mixed Integer Linear Programming Method for Simultaneous Multi-Periodic Train Timetabling and Routing on a High-Speed Rail Network

2020 ◽  
Vol 12 (3) ◽  
pp. 1131
Author(s):  
Wenliang Zhou ◽  
Xiaorong You ◽  
Wenzhuang Fan
Keyword(s):  
Linear Programming ◽  
Integer Linear Programming ◽  
Mixed Integer Linear Programming ◽  
High Speed ◽  
Programming Model ◽  
Mixed Integer ◽  
High Speed Rail ◽  
Train Timetabling ◽  
Train Timetable ◽  
The Impact

To avoid conflicts among trains at stations and provide passengers with a periodic train timetable to improve service level, this paper mainly focuses on the problem of multi-periodic train timetabling and routing by optimizing the routes of trains at stations and their entering time and leaving time on each chosen arrival–departure track at each visited station. Based on the constructed directed graph, including unidirectional and bidirectional tracks at stations and in sections, a mixed integer linear programming model with the goal of minimizing the total travel time of trains is formulated. Then, a strategy is introduced to reduce the number of constraints for improving the solved efficiency of the model. Finally, the performance, stability and practicability of the proposed method, as well as the impact of some main factors on the model are analyzed by numerous instances on both a constructed railway network and Guang-Zhu inter-city railway; they are solved using the commercial solver WebSphere ILOG CPLEX (International Business Machines Corporation, New York, NY, USA). Experimental results show that integrating multi-periodic train timetabling and routing can be conducive to improving the quality of a train timetable. Hence, good economic and social benefits for high-speed rail can be achieved, thus, further contributing to the sustained development of both high-speed railway systems and society.

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 Impact of demand response on BIPV and district multi-energy systems design in Singapore and Switzerland

2021 ◽  
Vol 2042 (1) ◽  
pp. 012096
Author(s):  
Christoph Waibel ◽  
Shanshan Hsieh ◽  
Arno Schlüter
Keyword(s):  
Demand Response ◽  
Programming Model ◽  
Systems Design ◽  
Energy Systems ◽  
Mixed Integer ◽  
Peak Shaving ◽  
Climate Conditions ◽  
Building Integrated Photovoltaics ◽  
Energy Hub ◽  
The Impact

Abstract This paper demonstrates the impact of demand response (DR) on optimal multi-energy systems (MES) design with building integrated photovoltaics (BIPV) on roofs and façades. Building loads and solar potentials are assessed using bottom-up models; the MES design is determined using a Mixed-Integer Linear Programming model (energy hub). A mixed-use district of 170,000 m2 floor area including office, residential, retail, education, etc. is studied under current and future climate conditions in Switzerland and Singapore. Our findings are consistent with previous studies, which indicate that DR generally leads to smaller system capacities due to peak shaving. We further show that in both the Swiss and Singapore context, cost and emissions of the MES can be reduced significantly with DR. Applying DR, the optimal area for BIPV placement increases only marginally for Singapore (~1%), whereas for Switzerland, the area is even reduced by 2-8%, depending on the carbon target. In conclusion, depending on the context, DR can have a noticeable impact on optimal MES and BIPV capacities and should thus be considered in the design of future, energy efficient districts.

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 Supply chain optimization with variable demand by considering financial criteria and scenarios

2017 ◽  
Vol 26 (44) ◽  
pp. 21 ◽  
Author(s):  
John Willmer Escobar
Keyword(s):  
Supply Chain ◽  
Large Scale ◽  
Net Present Value ◽  
Programming Model ◽  
Supply Chain Design ◽  
Mixed Integer ◽  
Supply Network ◽  
Distribution Centers ◽  
Supply Chain Optimization ◽  
Starting Point

This paper contemplates the supply chain design problem of a large-scale company by considering the maximization of the Net Present Value. In particular, the variability of the demand for each type of product at each customer zone has been estimated. As starting point, this paper considers an established supply chain for which the main problem is to determine the decisions regarding expansion of distribution centers. The problem is solved by using a mixed-integer linear programming model, which optimizes the different demand scenarios. The proposed methodology uses a scheme of optimization based on the generation of multiple demand scenarios of the supply network. The model is based on a real case taken from a multinational food company, which supplies to the Colombian and some international markets. The obtained results were compared with the equivalent present costs minimization scheme of the supply network, and showed the importance and efficiency of the proposed approach as an alternative for the supply chain design with stochastic parameters.

scholarly journals The Effects of Spatial Harvest Scheduling Constraints on the Value of a Medium-Sized Forest Holding in the Southeastern United States

2005 ◽  
Vol 29 (4) ◽  
pp. 185-193 ◽  
Author(s):  
Wise H. Batten ◽  
Pete Bettinger ◽  
Jianping Zhu
Keyword(s):  
Net Present Value ◽  
Southeastern United States ◽  
Economic Value ◽  
Forest Planning ◽  
Harvest Scheduling ◽  
Present Value ◽  
Period 2 ◽  
Planning Technique ◽  
Programming Solution ◽  
Forest Plans

Abstract Forest plans related to a number of spatial harvest scheduling scenarios were developed for a medium-sized forest holding using a heuristic forest planning technique (tabu search). Green-up periods of 2 to 7 years were assessed in conjunction with the two types of adjacency constraints. The results indicate for this one property that a short green-up period (2–3 years) did not significantly affect the economic value of the forest holding studied. Longer green-up periods and smaller maximum clearcut sizes could reduce the net present value of this forest holding by as much as 5 to 15% depending on the clearcut adjacency rules used. In a validation of the heuristic solutions, we found that the best solution generated with the heuristic (for three separate problems) was within 0.25% of the integer programming solution. South. J. Appl. For. 29(4):185–193.

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