TDWT826785 1202..1213


Grid-connected distributed energy generation system planning and
scheduling

W.S. Ho, H.Y. Chin, K.C. Wong, Z.A. Muis, H. Hashim*

Process Systems Engineering Centre (PROSPECT), Faculty of Chemical Engineering, Universiti Teknologi
Malaysia, 81310 Skudai, Johor, Malaysia
Tel. +60 7 5535478; Fax: +60 7 5588166; email: haslenda@cheme.utm.my

Received 19 March 2013; Accepted 1 April 2013

A B S T R A C T

Conservation of fossil fuel energy, energy management (peak shaving), energy economic and
pollution of energy sector has been among the recent topics of discussion. This paper
examines possibilities of achieving the said topics through an integrated energy system also
known as distributed energy system (DES) consisting of renewable energy and energy storage
devices. With aim to minimise system cost while abiding to carbon footprint reduction target
and pollutant emissions limit, a mixed integer linear programming model is developed for
optimisation and planning of a DES. Universiti Teknologi Malaysia, in planning to become an
eco-campus, is taken as a case study for this research work. The model reveals that with a
target of 40% carbon footprint reduction and 30 tonne of total nitrogen oxides emissions (in a
year), an annual cost of 5,687,000 $/y is required, achieving a reduction of 17.3%.

Keywords: Distributed energy system (DES); Energy storage (ES); Carbon footprint; Nitrogen
oxides (NOx); Renewable energy (RE); Mixed integer linear programming (MILP)

1. Introduction

Fossil fuels are the main element that drives our
economy today. Unfortunately, our dependency on
the world petroleum and natural gas reserve leads to
energy crisis which subsequently causes increasing
price of daily groceries, fuels and especially electricity
bills, affecting mostly the end users, residential, com-
mercial and industrial users alike. In order to be less
affected by the fluctuating price of global fossil fuels,
users can consider producing power through renew-
able energy (RE) resources incorporated with load

shifting strategy (through energy storage (ES) devices)
for better efficient energy utilisation and management
through a distributed energy generation (DEG) system
[1–4].

In fact, load shifting can solely be implemented on
a grid-connected energy system without local energy
production, to reduce the overall cost of electricity
although increases in energy consumption may be
expected due to compensation of energy losses during
current inversion and charging/discharging of energy
in and out of ES [5]. As for local RE systems, ES
benefits the system by balancing out and distributes
energy produced by intermittent resources such as

*Corresponding author.

Presented at the Fifth Annual International Conference on “Challenges in Environmental Science & Engineering—CESE 2012”
Melbourne, Australia, 9–13 September 2012

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doi: 10.1080/19443994.2013.826785

52 (2014) 1202–1213

January