Transcritical CO2 heat pump systems integrated with renewable energy sources and energy storage are being paid great attention to develop sustainable energy and energy savings in civil and industrial applications so as to achieve net-zero carbon emissions by 2050. This paper presents a comprehensive review on the progress in research and technology development of transcritical CO2 heat pump technology with clean energy and energy storage systems. Transcritical CO2 heat pump systems are very competitive with conventional systems for space heating

hot water production

air-conditioning

waste heat recovery and other engineering applications. This review focuses on the recent advances in the key research and technology development of transcritical CO2 heat pump integrated energy systems including sustainable ‘green’ heating

energy storage

electro-thermal storage

waste heat recovery and disruptive electrification of renewable energy

combined heating and power

and new hybrid systems using transcritical CO2 heat pump systems. The electrification of heat is a key opportunity for industry and is crucial for tackling the climate emergency. Future research needs of transcritical CO2 heat pump integrated systems are identified according to this comprehensive review. Furthermore

Perspectives and deployment of transcritical CO2 heat pump systems integrated with renewable energy sources and energy storage technology are discussed.