Demand response has been studied in district heating connected buildings since the rollout of smart, communicating devices has made it cost-effective to control buildings’ energy consumption externally. This research investigates optimal demand response control strategies from the district heating operator perspective. Based on earlier simulations on the building level, different case algorithms were simulated on a typical district heating system. The results show that even in the best case, heat production costs can be decreased by only 0.7%. However, by implementing hot water thermal storage in the system, demand response can become more profitable, resulting in 1.4% cost savings. It is concluded that the hot water storage tank can balance district heating peak loads for longer periods of time, which enhances the ability to use demand response strategies on a larger share of the building stock.

This study examines the influence of demand response control strategies on thermal conditions, indoor air CO2 concentration, heating energy cost and consumption in an educational office building heated by district heating system in a cold climate. The real-time pricing-based demand response is applied for space heating, heating of ventilation and adjustment of air flow rates. The ventilation analysis covers both constant and variable air volumes systems. The applied demand response algorithms regulate room air temperature set points for space heating, temperature set point for supply air and CO2 set point adjusted with the variable air volume ventilation system. The accepted room air temperature range was 20-24.5°C and CO2 concentration within 800-1200 ppm. This study was conducted with the validated dynamic building simulation tool IDA ICE. The results illustrate that the maximum yearly savings by demand response of space heating and ventilation with the constant air volume ventilation system are around 3 and 6% for the heating energy consumption and heating energy cost, respectively. For the variable air volume system, the heating energy consumption, heating energy cost, electricity consumption and electricity cost can be saved by demand response control up to 8, 11, 9 and 2%, respectively.

Demand side management will play a major role in future energy systems. However, while they have been explored in some depth for electricity grids, a similar progress has not been made for district heating networks (DHN). To this end, the current work field-tested the effect of demand side management, in the form of price based, demand response (DR) events, in the DHN catering to a university building. Responding to variations in a pricing model, the temperature of inlet water was varied from the heating water substation. Using combinations of parameters, 11 different DR scenarios were executed. To gauge the effect of the DR interventions, inlet water temperature, room air temperature, and occupant satisfaction were monitored. Depending on the constraints imposed, significant variations in the inlet water temperature and peaks and drops in the room air temperature were noted. The different DR scenarios did not greatly alter occupant satisfaction levels. The study was able to provide useful data from field tests of DR events in a DHN. The data also showed that price based DR events may be triggered and executed without significantly impacting occupant satisfaction with thermal comfort of the premises.

This study examined three different approaches to reduce the heating cost while maintaining indoor thermal comfort at acceptable levels in an educational office building, including decentralized (DDRC) and centralized demand response control (CDRR) and limiting peak demand. The results showed that although all these approaches did not affect the indoor air temperature significantly, the DDRC method could adjust the heating set point to between 20–24.5 °C. The DDRC approach reached heating cost savings of up to 5% while controlling space heating temperature without sacrificing the thermal comfort. The CDRC of space heating had limited potential in heating cost savings (1.5%), while the indoor air temperature was in the acceptable range. Both the DDRC and CDRC alternatives can keep the thermal comfort at good levels during the occupied time. Depending on the district heating provider, applying peak demand limiting of 35% can not only achieve 13.6% maximum total annual district heating cost saving but also maintain the thermal comfort level, while applying that of 43% can further save 16.9% of the cost, but with sacrificing a little thermal comfort. This study shows that demand response on heating energy only benefited from the decentralized control alternative, and the district heating-based peak demand limiting has significant potential for saving heating costs.