LAUSR

Abstract In Northern China, coal-fired power plants play a key role in electricity and heat generation, significantly intensifying air pollution. Meanwhile, a large percentage of wind power is curtailed every year owing to its conflict with heat supplies during the winter period, leading to a huge amount of energy waste. The flexibility of district heating systems has the potential to solve this problem and has attracted considerable attention from electric power system operators, thermal power plant owners, and policy makers. In this paper, a comprehensive survey on the potential of district heating systems in accommodating fluctuating heat supply and demand is proposed. The work first provides an overview of district heating systems in Northern China and how to quantify the flexibility of district heating systems. Next, the flexibility requirements and enhancement strategies of the district heating systems in northern China are thoroughly reviewed. The survey indicates that there is still great potential for the development of a flexible heating system. Moreover, state-of-the-art topics are addressed, including the challenges to be overcome and the status quo of clean heating provision, wind curtailment mitigation, and industrial waste heat utilization. Finally, this paper discusses future directions for deploying the flexibility of district heating systems in northern China, including new heat sources, digitalization, demand-side management, heat market deregulation, and energy policy reform.