Impacts of demand response from buildings and centralized thermal energy storage on district heating systems

Dmytro Romanchenko,Emil Nyholm,Mikael Odenberger,Filip Johnsson

doi:10.1016/j.scs.2020.102510

Dmytro Romanchenko, Emil Nyholm + Show 2 more

Open Access

https://doi.org/10.1016/j.scs.2020.102510

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Abstract

Energy use for space heating is a substantial part of total energy end use and heating systems can offer some flexibility in time of use, which should be important in future energy systems to maintain balance between supply and demand. This work applies a techno-economic, integrated, demand-supply optimization model to investigate the combined effect of using demand-side flexibility from buildings, by allowing for indoor temperature deviations (both up- and downward from the set-point), and supply-side flexibility, by applying thermal energy storage (TES), on the operation of district heating (DH) systems.The results indicate that the potential for increased indoor temperature, i.e., demand response (DR), is concentrated to multi-family and non-residential buildings (heavy buildings with high time-constants), while the potential for downregulation of the temperature, i.e., operational energy savings, is utilized to a greater extent by single-family buildings (light buildings). It is also evident that the value of DR diminishes in the presence of a supply-side TES. We show that applying both the demand-side flexibility and a centralized TES is complementary from the heating system perspective in that it results in the lowest total space heating load of the buildings and the lowest running cost for the DH system.

Highlights

Flexibility in thermal networks, i.e., district heating (DH) and cool ing systems, has been suggested as an important way to facilitate the use of high levels of renewable energy resources in the energy system (Lund, Lindgren, Mikkola, & Salpakari, 2015; Paiho et al, 2018)
The modeling results show that the demand response (DR) in the buildings, in terms of indoor temperature changes, depend on the building type and whether or not a centralized thermal energy storage (TES) is available within the DH system
The results show that the potential of upregulation of the indoor temperature is utilized to a greater extent by the multi-family dwellings (MFDs) and non-residential buildings (NRBs), while the potential of downregulation is utilized to a greater extent by the single-family dwellings (SFDs)

Summary

Introduction

Flexibility in thermal networks, i.e., district heating (DH) and cool ing systems, has been suggested as an important way to facilitate the use of high levels of renewable energy resources in the energy system (Lund, Lindgren, Mikkola, & Salpakari, 2015; Paiho et al, 2018). Studies have investigated the effects of centralized TES tanks on the operation of DH systems (e.g., Bachmaier, Narmsara, Eggers, & Herkel, 2016; Buoro, Pinamonti, & Reini, 2014; Li, Rezgui, & Kubicki, 2020; Oluleye, Vasquez, Smith, & Jobson, 2016) and other studies have examined the effects of the space heating demand response (DR) in buildings, i.e., the utilization of the thermal inertia of buildings as TES, on the operation of DH systems (e.g., Cai et al, 2018; Ingvarson & Werner, 2008; Kensby, Trüschel, & Dalenback, 2015; Li & Wang, 2015) All these studies concluded that availability of a TES benefits operation of energy systems, e.g., by reduced running costs or allowing greater shares of variable renewable energy sources such as wind and solar power. This limits the flexibility potential of buildings to a simu lated (pre-defined) DR profile and does not account for the feedback mechanism between supply and demand, e.g., the effects of changed space heating demand from buildings on the heat generation in DH systems

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