Jurnal Natural Vol. 22, (1) 2022 DOI 10.24815/jn.v22i1.23187 pISSN 1411-8513 eISSN 2541-4062 ORIGINAL RESEARCH Vol. 22 | No. 1| February 2022 51 Optimization of fuzzy entropy on solar panel’s motor MUHAMMAD IKHWAN 1 , MARWAN RAMLI 1* , MARDLIJAH 2 1 Department of Mathematics, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia 2 Department of Mathematics, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia Abstract. Renewable energy has been in great demand by the public, even some countries have set regulations for substitution and transition from fossil energy to renewable energy. This study aims to modify the fuzzy control system with a metaheuristic method, namely fuzzy entropy. The entropy value of the fuzzy set in the previous stage becomes the basis for calculating the foot of uncertainty in the new fuzzy set. This process makes the entropy method parallel to other optimization methods that have been carried out on fuzzy control systems. The results obtained indicate that the modified fuzzy control system successfully controls the angular velocity of the solar panel. The error value shown is very small and the time to reach stability is below 5 second. This is a rapid development of several previous studies. The modified system has no overshoot and steady state error below 1%. Based on these results, entropy research can be developed again by changing the fuzzy set to a more complex form. Keywords: Direct current motor, entropy, fuzzy logic controller, solar tracker, sun altitude. INTRODUCTION The Government of Indonesia has set a target of increasing the use of renewable energy in the national energy mix to 23% by 2025 [1]. This statement is found in government regulation number 79 of 2014, which relates to national energy policy [2]. In addition to the 2025 target, Indonesia is expected to be able to use 31% renewable energy by 2050 [3]. Renewable energy is also one of the government's 35,000 MW program's focal points. Renewable energy accounts for 25% of the program's total capacity, or 8,750 MW. Indeed, according to Presidential Regulation No. 22 of 2017 [4], Indonesia was still 95% dependent on fossil energy in 2015, while renewable energy accounted for only 5%. Solar energy is one type of renewable energy that is readily available in Indonesia. Indonesia's geographical location at the equator is one of the factors assisting in meeting the country's renewable energy targets. The average intensity of solar radiation in Indonesia is quite high, at around 4.8 kWh/m 2 per day [5]. Solar panels, which are currently being mass- produced, are used in the solar energy harvesting process. The solar tracking system ensures that the solar panels receive sunlight. Researchers have conducted research on solar tracking systems using conventional PID control designs [6]. The results show that the model used does not accommodate the solar panel model, so efficiency cannot be calculated. Another study compared PID and T2FSMC and obtained data on the angular position of the motor based on constant angular velocity [7]. Mardlijah [8] shows how T2FSMC is used on a one-axis sun tracker to account for light intensity and the firefly algorithm during the optimization process. When compared to static solar panels, the results of the evaluation of the received solar radiation intensity are around 35% -38% in the design and implementation of two active solar tracking systems, one axis and two axes, and the maximum power efficiency increase is 20% [9]. The controller that uses fuzzy sets depends on setting the boundaries at the foot of the fuzzy set [10]. In certain cases, trial and error methods can solve control problems, but there are often uncertainties that require precise fuzzy adjustments [11]. This study proposes a method for developing fuzzy sets. Other studies have used several heuristic methods such as particle swarm optimization, firefly algorithm, and others [8,12]. The fuzzy *Corresponding Author: marwan.math@unsyiah.ac.id Received: October 2021| Revised: February 2022| Accepted: February 2022