1. Introduction
Owing to the considerable social and environmental concerns, environment and energy issues are two of the main motivations of global sustainable development [
1]. In particular, certain countries have struggled to achieve two goals, economic growth and energy savings [
2]. Among these countries, Thailand is one of the major countries attempting to contribute energy savings [
3]. In 2013, approximately 8.58% of the final electricity consumption was produced by total renewable energy resources (14,107 GWh from 164,322 GWh of the final consumption) [
4]. Although this share is not insignificant compared to other countries, the electricity generated from renewable energy resources, which are one of the most appropriate to use renewable energy facilities, could be larger than the current amount of renewable energy facilities [
5]. Moreover, the majority of renewable energy facilities currently used in Thailand are hydro and biomass facilities (
Table 1; [
5]). Therefore, solar and wind energy have significant potential.
Moreover, because Thailand which is one of the nations in the United Nations Framework Convention on Climate Change (UNFCCC), agreed the Paris Agreement which presents the Intended Nationally Determined Contribution (INDC), the government of Thailand should attempt to reduce the emission of greenhouse gases (GHG) by utilizing renewable energy resources [
6].
Table 2 summarizes key descriptions which are applied to Thailand.
As the initial part of Thailand national government’s contribution, the government has aimed to apply renewable energy facilities in public buildings for energy savings [
8]. Among these buildings, public education institutes are required to contribute to energy saving through the installation of renewable and sustainable energy facilities [
9].
Currently, Thailand has employed a long-term national energy and electricity planning policy which is called as the Power Development Plan (PDP) from 2015 to 2036 [
10]. The majority of PDP considers the production and distribution of renewable energy facilities in Thailand. That is, renewable energy and its facilities are among the top priorities in the successful applications of PDP. Because dependence on fossil fuels can be environmentally and economically unsustainable with notable heavy burdens on the national economy, Thailand’s government hopes to fully revise its national energy systems with renewable energy. Based on the key concept of PDP, the Alternative Energy Development Plan 2015 was introduced and employed for the reduction of dependence on fossil fuels and the promotion of using alternative energy facilities from 7279 MW to 19,635 MW-capacity (2014–2036).
However, only few studies have investigated and explored the potentiality and possibilities of renewable energy facilities in Southeast Asia.
Table 3 summaries the findings of previous studies which were conducted in Southeast Asia.
As presented in
Table 3 and the findings of previous studies conducted in Southeast Asia, there are notable economic burdens in successfully diffusing renewable energy production facilities. Thus, several nations have attempted to preferentially employ the facilities with the considerations of their public institutions and organizations [
17,
18].
Therefore, the current study introduces the optimal configuration of renewable energy generation systems for Chiang Mai University, which is one of the largest public universities in Thailand. Using HOMER software (Hybrid Renewable and Distributed Generation System), the possible components of the configuration are introduced by reducing the environmental pollution and the dependence on the national grid system. Although there are notable limitations of HOMER software in exploring the feasibility of renewable resources including the needs of time-series datasets, notable time consumption, and certain criteria on converge, HOMER software can consider multiple combinations of different energy-related technologies, provide relatively precise results, and present optimized configurations of energy production systems [
19]. That is, the current study aims to respond to the following research questions.
Research question 1 What is the optimal renewable electricity production system for Chiang Mai University in Thailand?
Research question 2 How much are the amount of greenhouse gas emissions reduced by as a result of using the optimal system for the university?
5. Results
Table 5 and
Figure 5 list the optimal configuration composed by PV arrays, wind turbines, a converter, and batteries.
Table 6 shows the total and annual costs of the components in the simulation. The combination of 12,780 kW-capacity of the PV arrays, 17,965 battery units with a 1525 kW-capacity of the electric converter is suggested to respond to the electricity demand of Chiang Mai University.
The optimal configuration shows
$5,168,399 of the annual costs with
$0.728 per kWh of the COE level. The cash flow is introduced in
Figure 6. The annual electricity production was estimated to be 20,768,330 kWh.
Figure 7 presents the monthly electricity production. The monthly PV power production and battery state of charge are presented in
Figure 8 and
Figure 9, respectively.
The key findings from the simulation results in the current study could be introduced as follows. First, the combination of PV array-batteries-converter was proposed for Chiang Mai University. Second, the suggested configuration from the simulation shows $70,147,828 of the total NPC level with $0.728 kWh of the COE level. Third, the optimal configuration meets the 100% renewable fraction, because the purpose of this study was to present independent renewable electricity generation systems for Chiang Mai University.
Moreover, there are the notable amounts of the annual reduced environmental pollutants of the proposed configurations, instead of using the current grid system. 4,487,738 kg of CO, 19,456 kg of SO, and 9515 kg of NO and NO cannot be annually emitted by employing the proposed configuration in this study.
6. Discussion and Conclusions
To respond rapidly to the increased electricity demand in countries with sustainable development, and to reduce environmental pollution, several countries have set national plans and policies for renewable energy production facilities [
34]. Following this effort, the current study proposes the potential configuration of renewable energy production facilities for Chiang Mai University in Thailand to utilize local renewable resources. Two economic evaluations, COE and NPC, were used to assess the economic feasibility of the configuration. Related to research question 1, the potentially optimal configuration was organized by 12,780 kW-capacity PV array, 17,965 battery units, and 1525 kW-capacity electronic converter.
The configuration, which was composed of a PV array, a converter and batteries with a 5.38% annual real interest rate, achieved a $0.728 per kWh COE with a 100% renewable fraction. The results of the simulation shows the possibility of an eco-friendly campus in Thailand by presenting the potential configuration of renewable energy generation systems for Chiang Mai University. Although the simulation results show heavy initial capital costs, the suggested systems can be practical in allowing the university to be a long-term eco-friendly campus. In addition, because the simulations did not consider the national grid system, which is used as the current electricity system of the university, the suggested systems can achieve greater performance by trading the electricity between the suggested systems and the grid connection. Moreover, using the suggested system shows the significantly reduced environmental pollutants. Related to research question 2, the emissions of greenhouse gas are notably reduced. Moreover, compared to the current electricity system of Chiang Mai University, 179,510 kg of CO, 778 kg of SO, and 381 kg of NO and NO can be annually eliminated when the suggested system is installed and operated. It means that using the suggested system can provide environmental benefits for the university.
Compared to the findings of several previous studies conducted in Southeast Asia [
12,
14], the simulation results of the current study indicated that the suggested configuration can achieve 100% of renewable fraction with
$0.728 per kWh of COE. Considering the suggested configuration of previous studies in Thailand [
14], the suggested configuration in the current study excluded the usage of diesel generators. Considering about
$0.858 per kWh of COE is provided by the national grid system in Thailand [
35], the COE level presented by the suggested system,
$0.728 per kWh of COE, is considered as the economical configuration.
This study had several limitations. First, other policies on renewable energy in Thailand were not considered. For example, the Thailand government started to apply feed-in-tariff policies to power production facilities [
36,
37]. Second, economic theories that can be used in the energy industry were not considered in the simulations. Prior studies found that there are notable economic theories validated in the renewable energy industry [
38]. Third, the economic dynamics of developing countries were not considered. Several scholars indicated that the economic dynamics of developing countries can be a main hindrance to diffusing renewable energy facilities [
39]. For example, the pay back period with the internal rate of return of the suggested system can be considered. Third, because the amount of electricity considered in Chiang Mai University is significantly heavy to simulate (17,654,195 kWh), the current study employs the 50% scaled electricity load information. Therefore, future studies should extend the findings of the current study by addressing these limitations.