Modeling of a Biomass-based Energy Production Case Study Using Flexible Inputs with the P-Graph Framework

Abstract

In this work, a modeling technique utilizing the P-Graph framework was used for a case 1
 study involving biomass-based local energy production. In recent years, distributed energy systems 2
 gained attention. These systems aim at satisfying energy supply demands, supporting the local 3
 economy, decreasing transportation needs and dependence on imports, and in general obtaining a 4
 more sustainable energy production process. Designing such systems is a challenge, for which novel 5
 optimization approaches were developed to help decision-making. Previous work used the P-Graph 6
 framework to optimize energy production in a small rural area, involving manure, intercrops, grass, 7
 and corn silage as inputs, and fermenters. Biogas is produced in fermenters, and Combined Heat 8
 and Power (CHP) plants provide heat and electricity. A more recent result introduced the concept of 9
 operations with flexible inputs in the P-Graph framework. In this work, the concept of flexible inputs 10
 was applied to model fermenters in the original case study. A new implementation of the original 11
 decision problem was made both as a Mixed-Integer Linear Programming (MILP) model and as a 12
 purely P-Graph model by using the flexible input technique. Both approaches provided the same 13
 optimal solution, with a 31% larger profit than originally reported.