Sistem pemantauan energy listrik berbasis Internet of Things (IoT) yang terhubung dengan website menjadi salah satu solusi dalam peningkatan kapasitas, efisiensi dan kemudahan dalam menjalankan audit energy listrik sebagai upaya konservasi energy listrik. Sistem pemantauan ini diletakkan pada panel induk utama gedung untuk mendapatkan data pengukuran. PM2120 yang digunakan dalam sistem pemantauan ini telah berstandar industri dengan prosentasi error pengukuran dibawah 1%. Komunikasi Modbus berbasis RS485 digunakan untuk mengakses data pada ESP32. Data yang dikirimkan PM2120 merupakan data tegangan, arus, daya, energy (aktif, reaktif dan semu), frekuensi, power factor, harmonisa arus dan harmonisa tegangan yang diukur dari pane induk utama gedung. Sistem pemantauan energy listrik ini diterapkan pada gedung perkantoran yang menggunakan AC dengan total luas ruangan sebesar 1026 m2. Berdasarkan data tersebut, standar Instensitas Konsumsi Energi (IKE) gedung tersebut sebesar 4.4 kWh//bulan atau 52.73 kWh//tahun. Nilai ini menujukkan bahwa gedung tersebut termasuk dalam kriteria sangat efisien.

The global warming issue has been resolved through Sustainable Development Goals (SDGs) agreed upon by the world. One of the SDGs is affordable and clean energy. Green energy, such as solar energy, is a solution to realize it. Solar energy has massive potential as renewable energy in tropical countries. On the one side, solar energy is an excellent renewable energy. On the other side, solar energy has a low maturity level of technology. It is proven by the extravagant investment cost of building a solar power plant. Indonesia has an investment cost of up to 1200 USD per kWh, which is unsuitable for household applications. This investment cost will continue to be higher when it uses an IoT system for monitoring or managing the solar power plant. The low-cost solar power plant was designed using a hybrid system to reduce the investment cost. The industrial standard components include ACS712 as a current sensor, ZMPT101B as an AC voltage sensor, and ESP32 as a data processor and IoT module. The Blynk platform, connected to ESP32, is a web-based monitoring system. The success parameter consists of the DC voltage and current from battery and solar panel, AC voltage and current from single phase inverter. The low-cost solar power plant is designed in a 1.92 kWh battery pack with 1 kWh of AC continuous output power with total investment cost 1080 USD. The proposed solar power plant design decreases an investment cost by 14.29% up to 50.00 % per kWh.