A demand scenario based fuelwood supply chain: A conceptual model Garyfallos Arabatzis a,n , Konstantinos Petridis a , Spyros Galatsidas a , Konstantinos Ioannou b a Department of Forestry and Management of the Environment and Natural Resources, Democritus University of Thrace, Pantazidou 193, 68200 Orestiada, Greece b Laboratory of F. Informatics, Department of Forestry and Natural Environment, Aristotle University of Thessaloniki, Thessaloniki, Greece article info Article history: Received 18 June 2012 Received in revised form 4 May 2013 Accepted 13 May 2013 Keywords: Supply chain Fuelwood Mixed integer linear programming (MILP) Lagrangean relaxation Demand uncertainty abstract Fuelwood is one of the main fuels for heating in many countries. As the price of fuelwood is relative low, comparing to oil or gas, demand for fuelwood rises over the years. A supply chain is considered by different nodes that are essential for some operations concerning transportation and production. Due to the sensitive nature of the forest, which is the “production plant” in the examined supply chain, certain restrictions concerning the production and distribution of fuelwood should be taken into account. A more environment oriented production model should be developed taking into consideration the sustainable management of the forests. For this purpose a mixed integer linear programming (MILP) model is considered in modeling uncertainty for fuelwood demand. Moreover, the minimization of the overall operations cost is examined under different fuelwood demand representations using Lagrangean relaxation algorithm. & 2013 Published by Elsevier Ltd. Contents 1. Introduction ........................................................................................................ 687 2. RES and the use of fuelwood .......................................................................................... 688 3. Mathematical formulation............................................................................................. 689 3.1. The fuelwood supply chain ...................................................................................... 689 3.2. Forest production constraints .................................................................................... 690 3.3. Fuelwood balance constraints .................................................................................... 691 3.4. Non-negativity constraints ...................................................................................... 691 3.5. Objective function ............................................................................................. 691 3.6. Implemented policy for the use of fuelwood ........................................................................ 692 4. Solution approach ................................................................................................... 692 4.1. Description of the numerical example ............................................................................. 693 4.2. Results ...................................................................................................... 693 4.3. Sensitivity analysis............................................................................................. 694 5. Conclusions ........................................................................................................ 696 References ............................................................................................................. 696 1. Introduction The global interest in dealing with the energy crisis and securing the energy supply has led to the promotion of renewable energy sources (RES), in various sectors of the economy [1]. RES can improve the variety of supply in energy markets, reducing thus the dependence on oil; they can also help to safeguard sustainable energy sources on a long-term basis, and contribute to a reduction of the local and global environmental impact on regional sustainable development. RES account for 17% of the global primary energy production, mainly through large hydroelectric installations and the use of traditional types of forest biomass and agricultural residues in developing countries [2]. The sustainable management of biomass necessitates an improved rate of exploitation of natural resources, avoiding the depletion of natural carbon deposits. In recent decades, a Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews 1364-0321/$ - see front matter & 2013 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.rser.2013.05.030 n Corresponding author. Tel.: +302552041158. E-mail addresses: garamp@fmenr.duth.gr (G. Arabatzis), kpetridi@fmenr.duth.gr (K. Petridis), sgalatsi@fmenr.duth.gr (S. Galatsidas), ioannou.konstantinos@gmail.com (K. Ioannou). Renewable and Sustainable Energy Reviews 25 (2013) 687–697