The Institute of Electrical Engineering of the Chinese Academy of Sciences and Dahua Engineering Group have collaborated to design and build the Huangdicheng solar heating system with seasonal heat storage project, with the support of the Key technologies and demonstration of transformative clean energy of Strategic Priority Research Program of the Chinese Academy of Sciences (Class A) and the Special Project for Industrial Innovation and Development of Zhangjiakou Renewable Energy Demonstration Zone of National Development and Reform Commission. The project combines tower solar collector technology, flat-plate solar collector technology and seasonal heat storage technology to provide heat for the 300000 square meter building in Huangdicheng town, Zhangjiakou city, Hebei province. The whole project consists of three phases, Phase I was completed in April 2018, including 800m² tower solar collectors and 3000m³ water pit for heat storage; Phase II was completed in December 2021, including 12600m² flat-plate solar collectors, 2200 m2tower solar thermal collectors and 23000 m³ water pit for heat storage; Phase III is proposed to be completed by the end of 2022. The project has supplied heat to the Zhangjiakou Dahua Jianguo Hotel, the surrounding buildings and the biogas stations since 16 October 2019, which is the first solar heating system with seasonal heat storage project in China.
A total of 15600m² of solar collectors and 26000m³ water pit for heat storage can meet 60% of the heating heat of the 190000m² building in the Huangdicheng Dahua District. At present, the water pit for heat storage is 65%, and the cost of heating during the use period is 0.25 RMB/kWht, which is only 40% of the local electric heating price and 42% of natural gas. The economic and social benefits are obvious.