International Journal of Electrical and Computer Engineering (IJECE) Vol. 13, No. 4, August 2023, pp. 3885~3894 ISSN: 2088-8708, DOI: 10.11591/ijece.v13i4.pp3885-3894  3885 Journal homepage: http://ijece.iaescore.com Performance of low-cost solar radiation logger Agus Risdiyanto 1 , Ant. Ardath Kristi 1 , Agus Junaedi 1 , Bambang Susanto 1 , Noviadi A. Rachman 1 , Anwar Muqorobin 1 , Harjono P. Santosa 1 , Ahmad Fudholi 1,2 1 Research Center for Energy Conversion and Conservation, National Research and Innovation Agency, Bandung, Indonesia 2 Solar Energy Research Institute, Universiti Kebangsaan Malaysia, Bangi Selangor, Malaysia Article Info ABSTRACT Article history: Received Oct 22, 2021 Revised Jul 2, 2022 Accepted Jul 5, 2022 In solar power systems, irradiance value data are among the most important parameters. Such data can be used in installing photovoltaic (PV) modules, such as determining the exact location, tilt angle, and required area, for optimal power efficiency. In this study, the comprehensive simulation and implementation of a solar radiation meter with a PV cell and temperature sensor are presented. The irradiance measurement value is based on the power reading generated by the small capacity of the PV cell at a specific load converted into a digital value in the microcontroller using the implicit Newton polynomial interpolation (NPI) equation as a low-cost alternative method. The effect of temperature is included in the conversion to obtain precise measurement results. Firstly, the structure and characteristics of the PV cell are discussed. Secondly, the parameters, measuring method, and conversion of the measurement reading data using the NPI equation are presented to assess the results. Finally, the simulation of the solar radiation meter using the PSIM and implementation of the hardware are conducted to validate the concepts and compare their results. The proposed hardware has an average error of 2.72% in the implementation of the measurement test. Keywords: Irradiance Newton polynomial interpolation Solar energy Solar radiation meter Temperature sensor This is an open access article under the CC BY-SA license. Corresponding Author: Agus Risdiyanto Research Center for Electrical Power and Mechatronics, National Research and Innovation Agency Bandung 40135, Indonesia Email: agus032@lipi.go.id 1. INTRODUCTION The availability of renewable energy source (RES) data is fundamental before the implementation of renewable energy technology, especially in areas facing problems with electricity availability. For example, the application of solar power plants requires a solar radiation time series and meteorological variables as key elements for modeling the energy production of solar power plants. At present, using energy from renewable resources is a key factor in improving and adding benefits to society because it is sustainable [1], [2]. One such RES is solar energy, which is secure, clean, and available on earth throughout the year. Solar energy has great potential and vast application prospects that can be used to meet the majority of the total energy demand. The most promising, emerging solar energy technology is photovoltaic (PV) technology, which can transform solar radiation into electric energy through PV modules [3]–[6]. In conjunction with solar PV modules, as a new RES, the intensity of the sun is measured in watt per square meter (W/m 2 ), which is called irradiance [7]. The intensity of solar radiation is one of the most important parameters that must be determined before solar PV modules are installed to ensure their operation at the maximum power point (MPP) [8]–[10]. This task is complicated by the fact that this operating point changes significantly as a function of solar radiation and cell temperature, which can be illustrated by a typical current-voltage (I-V) curve of a PV array [11]–[14].