1. Introduction
Climate change and global warming are two of the most pressing issues of our day. As a result, the average atmospheric temperature is increasing. If this trend continues, the planet’s potential to sustain life will be lost in the future. The primary causes of such consequences are anthropogenic actions undertaken by humans [
1]. As seen in
Figure 1, Malaysia’s energy and electricity sectors account for 60% of the country’s greenhouse-gas emissions [
2,
3]. The usage of traditional energy resources to charge EVs has serious environmental repercussions [
4]. Severe concerns are being expressed in the present in regard to the rise in sea levels, the increases in the global air temperature, and the melting of the Arctic and Antarctic ice sheets; thus, many researchers have investigated wind energy in Malaysia [
5,
6].
Malaysia is currently looking for another alternative resource for generating electricity after having been dependent on coal and fuel. Coal and fuel are non-renewable resources, and their prices are rising in the global market due to supply shortages and political issues [
7]. Malaysia has taken steps to explore renewable energy resources as alternatives for generating electricity. Wind energy is the fastest-growing energy technology in the world, and it is considered to be one resource that meets the needs of modern societies in reducing their dependence on coal and diesel, whilst simultaneously delivering a substantial reduction in greenhouse-gas emissions [
8].
Malaysia is in a low-wind region compared to other countries. Monthly mean wind speeds range between 1.5 and 4.5 m per second [
9,
10,
11]. Despite that, the first wind farm in Malaysia, which was set up on Pulau Terumbu, Layang-Layang, Sabah, has demonstrated that wind energy is applicable only in certain locations in Malaysia, mainly in coastal areas (e.g., Kudat, Mersing, Langkawi, and Terengganu), with an average wind speed of 4–7 m/s. In most of the coastal cities in Malaysia, good wind speeds for small-scale turbines have been observed, but only at high elevations (60–90 m) [
12].
Large-scale wind farms are not a feasible solution for renewable energy in Malaysia due to the low wind speeds in the country [
13]. The ideal approach to utilizing wind energy in Malaysia is to implement small-scale wind turbines (WT) that provide around 3–10 kW of electricity [
12]. According to [
14], the power needed to charge 3 EVs overnight is estimated to be 9.6 kW to reach an 80% state of charge [
15]. Thus, the main aim of this paper is to investigate the feasibility of using a hybrid system consisting of a small-scale WT with a battery storage bank at a high elevation to power an electric-vehicle charging station in Malacca, Malaysia. The contribution of this study is a case study of small-scale wind-energy generators at high elevations, which have not been sufficiently analysed in Malaysia. Moreover, the study investigates the feasibility of EV charging based on small-scale wind turbines. Researchers, investors, and policymakers in regions with low wind speeds can benefit from this study’s findings.
This paper is organized as follows:
Section 2 discusses wind energy and wind speeds in Malacca.
Section 3 provides a description of the system configuration used in this study.
Section 4 discusses the energy consumption of the proposed charging station.
Section 5 discusses the assessment criteria and parameters used in the evaluation process.
Section 6 provides details about the system design using HOMER software, followed by results and a discussion in
Section 7.
4. Charging-Station Energy Consumption
The electric load profile is the primary determinant in the design and optimisation of an integrated hybrid energy system. Thus, it is critical to understand how load varies from weekdays to weekends and from season to season in order to design a hybrid system that maximises resource use while maintaining a low system cost [
24].
Charging infrastructures are determined by the relationships between driving requirements, charging equipment utilisation, EV stock, and technological capabilities. Population density, driving ranges, and charging habits are all distinct characteristics that have a direct impact on the placement of EV-supply equipment and charging rates for electric, low-duty cars.
Table 2 compares two charging modes, slow and fast charging, to determine the charging rate of an electric vehicle [
25].
Considering all of the previous information, and assuming that a slow port would charge 6 cars from 0% to 50% daily, which is sufficient for daily usage for the average person (150 km range), each 1 of the 6 charging ports would be charging a car to 50% capacity in a duration of 9 h, starting at 10 pm and finishing at 6 am, as shown in
Figure 4. No fast-charging port will be implemented due to the wind-speed constraints of Malaysia and small-scale WTs. In addition to that consideration, all of the cars have a 66 kWh battery (the standard battery for Tesla cars) [
26]. The decision was to use as the most realistic demand estimation a daily consumption of 198 kWh for the slow ports, using a type 2 AC charger with a 7 kW charging rate, for implementation in this project. This brings the total capacity of the charging port to 42 kW and the energy consumption to a total of 198 kWh daily.
7. Results and Discussion
This section includes a discussion of the HOMER optimization results as well as a technical and economic analysis of the standalone WT system. The optimization results from HOMER are highlighted in
Table 6.
The simulation results generated by HOMER show all of the possible configurations for the proposed system discussed above. The WT and battery system targeted in this project consist of 15 units of WTs, one string (720 V) of battery with a 510 kWh capacity, and a 21.4 kW converter. The total NPC is USD 76,855.33, with a cost of energy (COE) of USD 0.081/kWh, which is at the same level as the price of energy in Malaysia, as shown in
Table 6 and
Table 7.
The penetration of renewable energy for this system is 100% since it is a standalone system with no grid connection. The electricity production by the WT in Malacca is 214,272 kWh/year, as shown in
Table 6, which is adequate for the proposed charging station. Since the WTs are dependent on wind speed, in the period between June and September, the electricity generation will be higher due to the high wind speeds during the monsoon season in Malaysia.
8. Conclusions
Annually, the average wind speed in Malacca is about 2.29 m/s at the 10-metre hub-height according to MMD data. Based on power law calculations, the wind power is about 3.373 m/s at the 100-metre hub-height. The current electricity tariff in Malaysia is about USD 0.087 per kWh; these are key parameters in determining the feasibility of a WT. Therefore, using this as a site-specific parameter, the feasibility study was undertaken using a software package, HOMER. The finding of this study is that the annual production of the wind-powered EV-charging station would be 214,272 kWh annually, which would be sufficient for the proposed load. The total installed capacity of renewable energy is 75 kW, comprising 15 units of a 5 kW WT. The total capital costs and COE of the project are USD 28,717 and USD 0.081/kWh, respectively.
In summary, the study established that the suggested, small-scale WT for an EV-charging station would be technically possible and economically viable as a source of renewable energy using 5 kW WTs under the condition of using it at a high elevation to compensate for the low wind speeds common to Malaysia.
The study’s primary limitations are, first and foremost, the accuracy of the wind data. Unless and until real wind-speed measurements are taken at the suggested site, it is quite conceivable that the actual wind speed is different. The second limitation is that data on the turbine’s price and power curve, which are required to determine yearly energy output, can only be acquired from the makers. As a result, there is a chance that they have overstated the values on their turbines’ information sheets in order to facilitate the sale of their products.