Indonesian Journal of Electrical Engineering and Computer Science Vol. 30, No. 3, June 2023, pp. 1259~1268 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v30.i3.pp1259-1268  1259 Journal homepage: http://ijeecs.iaescore.com Design and fabrication of an IoT-based smart electrical meter for residential energy management Thanh Ba Nguyen, Tri Cao Nguyen Department of Electrical and Electronic Engineering, Institute of Engineering and Technology, Thu Dau Mot University, Thu Dau Mot, Vietnam Article Info ABSTRACT Article history: Received Aug 28, 2022 Revised Jan 27, 2023 Accepted Jan 31, 2023 Transparency in electricity measurement and efficient use of electricity are issues of concern to households. Electricity customers want to have confidence in their utility company's electricity meters installed at their houses. This study designs and constructs an internet of things (IoT)-based smart electric meter to measure electricity and remotely control domestic appliances. This device can monitor, calculate electricity bills and remotely control the appliances via the internet; electrical quantities are displayed in real-time on the Blynk app, liquid crystal display (LCD) screen and Google Sheet. The device is also capable of emailing the electricity user. The proposed system is designed and developed based on ESP32, a LCD, a PZEM 004T, four relays and a DC source. The results show that the device works stably and the device’s error is less than 5%. This research makes it possible for users to conveniently monitor their power consumption while enhancing their energy-saving awareness. Keywords: ESP32 Internet of things PZEM 004T Residential energy management Smart electrical meter This is an open access article under the CC BY-SA license. Corresponding Author: Thanh Ba Nguyen Department of Electrical and Electronic Engineering, Institute of Engineering and Technology Thu Dau Mot University Thu Dau Mot, Binh Duong, 75109, Vietnam Email: thanhnb@tdmu.edu.vn 1. INTRODUCTION In recent decades, the world economy in general has made great progress, leading to increasing demand for energy [1], [2]. There is a significant contribution from the area of residential buildings [3]. People are also looking for efficient energy management solutions for this area. In many countries, they still use traditional electric meters, electromechanical meters or electronic meters. These types of meters require staff to visit the meter location in each household for power readings and other administrative tasks [4], which causes more work for them as well as difficulty in ensuring transparency in measurement. These problems will be solved if an internet of things (IoT)-based smart meter is utilized instead. Nowadays, IoT is becoming the new technology trend [5], [6]. IoT environment is increasingly being researched for information security, so it is safer for users [7]. IoT aims at providing life easier and more convenient by monitoring various activities, including energy management [8]. The IoT enables a lot of smart solutions for various problems and saves energy to a great amount. Real-time monitoring helps households reduce more energy consumption than monitoring through monthly electricity bills [9], [10]. There have been a great number of studies on electrical energy meters using IoT [11]. The statistics of the different technological and functional aspects found in the literature review are illustrated in Table 1. To know electrical quantities, it is necessary to measure two fundamental quantities which are voltage and current. For electric current, there are two basic techniques: intrusive and non-intrusive. The ACS712