Acccesen provided the heat solutions for the No.6 Energy station of Beijing City Sub-center, which has a total construction area of 627,800 m2, designed thermal load of 18.8MW and cooling load of 38.2MW. The energy is supplied by the ground source heat pump, water storage, gas boiler and electric refrigeration multi-energy coupling mode. The renewable energy takes up 40%, which can provide clean energy for 10 million square meters of the sub-center. It can reduce carbon dioxide by 400,000 tons, sulfur dioxide by 580 tons, nitrogen oxide by 400 tons and soot by 225 tons every year. The sub-center will take the lead in entering the era of green and intelligent energy.