HOT|COOL NO. 2/2019 - "Smart Heating System Integration"



By Dirk Vanhoudt, senior researcher district heating and cooling networks, EnergyVille – VITO, Belgium; Tijs Van Oevelen, researcher district heating and cooling networks, EnergyVille – VITO, Belgium; Christian Johansson, CTO, NODA, Sweden

In the Horizon 2020 STORM project, a demand side management system for district heating and cooling networks was developed. The STORM controller was demonstrated in a modern low-temperature 4th generation network as well as in a traditional 3rd generation high- temperature network. In this article, we present the project, the developed controller and the results of the controller performance evaluation. THE IDEA The main objective of the project was the development, demonstration and performance assessment of a new type of intelligent demand side management system (DSM) for district heating and cooling networks. The STORM controller makes use of the flexibility present in the thermal capacity of the connected buildings to optimize production and distribution within the grid. Indeed, a lot of thermal mass is present in buildings, consisting e.g. of concrete and furniture. If thermal mass can be ‘activated’, i.e. by warming up or cooling down this mass slightly (less than 1°C), a lot of energy can be stored or consumed. In this way, the buildings act as a virtual storage buffer, without breaking indoor air comfort limits and indeed without anyone even noticing during normal operations. The harvested flexibility by the activation of the building mass is used for the benefit of the network or energy production plant operation, making it more efficient and more sustainable. The STORM controller concretizes this through the implementation of three control strategies. Firstly, the controller can shave off peaks in the network power demand, reducing the running hours of often expensive and fossil-fueled peak boilers. This is called the ‘peak shaving’ control strategy. Alternatively, the controller can also optimize the operation of CHP plants and heat pumps, i.e. enabling them to be switched on at high/low power prices. This control strategy is called ‘market interaction’. Finally, the operator is also capable of balancing heat demanders and heat producers in a cluster of a network, maximizing the self-consumption of excess energy in a cluster. This control strategy is called ‘cell balancing’. The STORM controller uses these control strategies either independently or in combination to optimize the operations of the district heating or cooling grid.

THE STORM PROJECT The STORM project ( started in April 2015 and ended in March 2019. During the project, two versions of the controller were developed. This means that, after the development and testing of the first version during a winter period, an update was performed, and the revised controller was tested again for a winter period. In that way, it was possible to develop a very performant, reliable product, ready for commercialization with a short time-to-market.

Figure 1: The production site of the Rottne DH network.

The project was realized by a slimconsortium. VITO-EnergyVille, a Belgian research center, was the coordinator of the project, and responsible for the controller algorithm development. NODA, a Swedish company offering smart district heating grid controllers, integrated the algorithms in their hard- and software platform. Additionally, two network operators were part of the consortium as demonstrators. Växjö Energi AB is a Swedish network operator in the main city of Växjö in the South of Sweden (Figure 1). They also operate a small, rather traditional, network of about 200 consumers in the community of Rottne which was used as a demonstration in STORM. This network mainly uses wood chips as fuel, supplemented with expensive bio-oil in their peak boilers. In this network, the aim was to minimize the peak oil consumption by means of peak shaving. The other demonstration network is operated by Mijnwater BV, and is located in Heerlen in the very south of the Netherlands. This is a highly innovative, very low temperature network, making use of water from flooded former coal mines for heating and cooling (Figure 2).


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