Deployment of Agent Based Load Control in District Heating Systems

This paper describes results and experiences from an industrial proof-of-concept installation of a multi-agent based load control system in three major district heating systems in Sweden. A district heating system is a demand-driven system, i.e. the consumption controls the level of energy input which the district heating producer needs to deliver into the system. The basic idea of load control is that the individual consumers can be utilized as heat load buffers which, when coordinated on a system-wide scale, can be used to adjust the total consumption demand instead of having to change the production scheme. Load control leads to several important benefits such as giving the district heating producer the capability to avoid using expensive and environmentally unsound peak load boilers, while at the same time lowering the overall energy consumption at the consumer side. In order for load control to work the system needs to be able to coordinate the behaviour of a large amount of consumer substations in relation to the dynamic status among a range of production units, while continuously maintaining a sufficient level of quality of service among the consumers. The results show that the multi-agent based system was capable of reducing the peak loads with up to 20% of the total load, and to lower the average energy consumption with about 7,5% without any deterioration of the experienced indoor climate. Different theoretical aspects of load control have long been studied, but it is not until recently that technical advances in hardware and communication infrastructure has made it possible to implement these schemes in real-world settings.