The IEEE 7th Conference on Energy Internet and Energy system Integration (EI2 2023) focuses on many innovative technologies and practical applications regarding "Energy Internet" and" Energy System Integration" (EI^2 in abbreviation). EI^2 couples multiple energy-systems, e.g. electricity, gas, heating, cooling and transportation, with energy storage and ICT technologies, including cloud computation, big data analytics, internet of things (IoT), mobile internet, artificial intelligence (AI) and 5G communication application, to promote the interconnection, openness, sharing and coordination of various energy resources and shape a green, low-carbon, efficient, low-cost and environment-friendly energy ecosystem