Monitoring Indonesia’s Energy Mix Achievement Using Simple Linear Regression

The energy crisis has become a global issue. It can be seen in various countries worldwide experiencing an energy crisis. The energy crisis and global warming encourage countries to use renewable energy sources significantly from time to time. Based on historical data of installed capacity, it can be calculated the installed capacity in 2025 using a simple linear regression method. Renewable energy generating capacity is obtained from this installed capacity, meeting 23%. The results of a simple linear regression show that in 2025, the installed capacity of renewable energy plants is 22.66%. It means that there is a deviation of 0.34% from the target. Meanwhile, for 2050, the achievement of the energy mix is 28.47%, which means that it is 2.53% lower than the target of 31%. Conformity between the general national energy plan and the regional one is essential.


INTRODUCTION
The energy crisis has become a global issue. It can be seen in various countries worldwide experiencing an energy crisis. Several situations that describe the energy crisis occur in developing countries and occur in major countries worldwide. The energy crisis and global warming encourage countries to significantly use renewable energy sources (RES). Besides the energy crisis, the issue of environmental pollution such as air pollution caused by burning fossil fuels and concerns about climate change and global warming, coupled with high oil prices (Shahin et al., 2015), encourages countries to make significant use of renewable energy sources. Increasing threats such as global warming, carbon emissions, and their relationship to energy consumption are among the most cited fields in environmental economics (Lilis et al., 2021). The problem of climate change is a significant challenge in sustainable development programs (Lilis et al., 2021). The increase in energy consumption and greenhouse gas emissions has damaged the social and economic life of the community (Lilis et al., 2021), (Jorgenson and Clark, 2016), (Kim and Jeong, 2016), (Ming et al., 2016). Besides the energy crisis, global warming and emission problems are also international issues.
Meanwhile, the operation of fossil fuel power plants has emissions that are harmful to the environment (Guvenc et al., 2012). Various efforts to reduce emissions have also been widely published (Hrvoje et al., 2013), reducing CO2 Emissions in the Cement Industry. Efforts to reduce CO2 emissions through Biogas, Wind, and solar energy have been published (Lilis et al., 2020). Climate change has also become an increasingly pressing issue on political agendas around the world, and this is not only because of environmental sustainability issues; but also because sustainability has an economic and financial impact (Joao, 2021).
The utilization of unlimited natural energy sources from the environment to be converted into electrical energy, while considering environmental aspects, provides many advantages for RES in their use, especially environmental protection (Dario, 2021). Using RES to substitute fossil energy sources requires consistency and coordination between central and regional This Journal is licensed under a Creative Commons Attribution 4.0 International License governments. Mohtasham (Javid, 2015) shows that applying any renewable energy (RE) requires a sustainability analysis, which depends on three main components, namely environmental impacts, externality costs, and economics and financing. Ellabban (Omar et al., 2014) shows the global benefits of RE production where they categorize them into environmental, economic, technological, social, and political aspects. In addition, they propose a RE market development process and describe the barriers to the deployment of RE technologies. In addition, (Peidong et al., 2009) presented the weaknesses of the RE development policy in China, which could be the lack of coordination and consistency of policies, the weakness, and incompleteness of the driving system, the lack of innovation in regional policies, the incomplete financing system for RE projects or low investment in research and technical development of RE. Sri Fadilah (Sri et al., 2020) explained the impact of RE consumption on the economic growth of ASEAN countries, where RE consumption and non-RE consumption, labor force growth, and capital stock have a positive relationship with the economic growth of ASEAN countries.
With more than 275 million people and the fourth largest population globally, Indonesia requires a vast electrical energy supply. On the other hand, Indonesia is blessed with RE sources with enormous potential and has not been fully utilized. The Indonesian Government is very active in promoting RE and reducing the resulting emissions. It is evidenced by the various policies that have been issued related to RE, both in government regulations, presidential regulations, and ministerial regulations. Based on historical data of installed capacity, it can be calculated the installed capacity in 2025 using a simple linear regression method. RE generating capacity is obtained from this installed capacity, meeting 23% of the total. This paper discusses the Indonesian Government's breakthrough in meeting the target of using RE in the 2025 energy mix.
The potential of RE sources in Indonesia is vast, but various challenges inequitable access to RE also need to be resolved. Some of the challenges referred to include production costs that are still relatively high, so they cannot compete with conventional energy, and some components of RE plants cannot be developed in Indonesia, so they still have to be imported so that it affects their maintenance. Besides the issue of production costs and components, policies to encourage investor interest are very much needed.
This paper consists of four main sections where the first section discusses the condition of power demand and supply in Indonesia, the second section discusses the methodology for meeting the targets, the third section presents the results and discussion, and the last section presents the conclusion.

Problem Formulation
Currently, the energy crisis and the greenhouse effect are international issues. Reserves of energy sources from fossil fuels are dwindling, while RES has enormous potential, and only a tiny part has been utilized. Based on 2018 Electricity Statistics, Directorate General of Electricity, Ministry of Energy and Mineral Resources, Indonesia, the production of electrical energy from all power plants in Indonesia in 2018 was 188698.46 GWh, of which 173952.42 GWh or 92.19% was supplied from thermal generators and the remaining 14746.05 or 7.81% supplied from RE generation. Thermal energy generators still dominate the fulfillment of electrical energy needs. Meanwhile, according to the 2019 Indonesia Clean Energy Status Report, Indonesia has 432 GW of RE potential, of which only 7 GW have been used commercially.
As a tropical country, Indonesia has enormous potential for RES. The potential of RES in Indonesia is shown in Table 1. The utilization of new and renewable energy (NRE) in 2015 was only 1.9% of the potential of NRE in Indonesia. Meanwhile, the installed PV capacity was 78.5 MW from 207,898 MW or 0.0378% solar potential in the same year. The installed PV capacity is only 0.9555% of the total installed RE in the same year, which is 8215.5 MW, while the government targets that in 2025, NRE is at least 23% of the total primary energy mixed 31% in 2025. 2050. Given the sizeable solar potential, the Government plans to develop PV of 6.5 GW in 2025 and 45 GW in 2050.
The energy crisis and emission problems encourage countries to use renewable energy significantly from time to time. Likewise with Indonesia, various policies encourage RE to substitute fossil fuels. Based on Presidential Regulation No. 22 of 2017, Indonesia has targeted the percentage of RE to be 23% in the energy mix in 2025 and 31% in 2017. These targets must be monitored to see the gaps that occur so that if there are gaps, the necessary strategic steps can be taken immediately. The installed capacity of electrical energy generation and the installed capacity of RE plants in Indonesia from 2003 to 2020 are shown in Figure 1.

Simple Linear Regression
The Simple Linear Regression (SLR) Analysis is used to obtain a mathematical relationship in an equation between the dependent variable and a single independent variable. A SLR equation is an equation model that describes the relationship of one independent variable/predictor (X) with one dependent variable/response (Y), which is usually depicted by a straight line, as shown in Figure 2.
The SLR equation is expressed mathematically by,

Y=a+b.X
(1) Where Y is the regression line (response variable), X is the  Figure 1: Indonesia's power generator capacity independent variable/predictor, a is the constant, the intersection with the vertical axis, and b is the regression constant (slope). The constants a and b, are determined using equations (2) and where N is the number of data.

Energy Mixed 2025
From equations (1), (2), and (3) it can be written the SLR formulation for the case of electric energy generation in Indonesia and RE generators, involving government policies that plan the construction of RE plants in [2019][2020][2021][2022][2023][2024][2025][2026][2027][2028]. The calculation of SLR uses historical data from 2003 to 2020 plus 2025 and 2028. The total installed capacity and RE installed capacity formulations are shown in equations (4) and (5), respectively.
where KAP TOT is the total installed capacity of the generator, KAP RE is the RE generation capacity, and t is the review time. So that the capacity for generating electricity and RE will be obtained as shown in Figure 3.   Figure 4. Figure 4 shows the synergies and synchronization of policies between the central government and local governments, which are an absolute necessity in achieving the energy mixed targets that have been announced.

Energy Mixed 2050
Based on the existing data of the total installed capacity from 2003 to 2020, equation (4) will show that the total generating capacity in 2050 is 158.56 GW. It is certainly not objective considering that it does not involve government policies. To calculate installed In 2050, the installed capacity of RE will be 98.566 GW. Thus, the RE mixed to energy sources totals 28.4695% in 2050. There is a deviation of 2.5305% from the 31% target. In other words, the utilization of RES is still 8.73368 GW less than the target. In 2050, the installed capacity of RE will be 98.566 GW. Thus, the mix of ER to energy sources totals 28.4695%.

CONCLUSION
This paper aims to monitor the achievement of the energy mixed targets in 2025 and 2050.