Business and socioeconomic assessment of introducing heat pumps with heat storage in small-scale district heating systems

Abstract

Fossil fuel-based CHP plants have a long history of supplying district heating (DH) in Denmark, however small-scale systems are progressively switching to biomass boilers for economic reasons. Biomass, however, should be reserved for other purposes where a storable fuel is pertinent. This paper investigates the transition of DH on the Danish renewable energy island Samsø. While already renewable energy-based through the use biomass, the system is neither socioeconomically optimal nor optimal in terms of integrating fluctuating renewable energy sources or using biomass resources appropriately. EnergyPLAN-based energy systems analyses of heat pump (HPs) replacing DH biomass boilers are used to investigate system impacts, the ability to integrate fluctuating renewables and overall systems costs. Secondly, optimal business economic design and operation of the DH plant are analysed using the energyPRO model where plant operation is optimised against an external electricity market.While heat pumps have a positive impact when factoring in the ability to exploit locally available fluctuating renewable energy sources and local biomass availability constraints, business economic analyses demonstrate a more uncertain feasibility of the potential switch and also demonstrate that significant flexibility through heat storage and overcapacity on heat pumps does not pay.

Energy scheduling of a smart microgrid with shared photovoltaic panels and storage: The case of the Ballen marina in Samsø

“…4) is the Ballen marina located in Samsø (Denmark), where a smart energy system is being installed and tested in the framework of the Horizon2020 European research project SMILE [54]. Samsø was appointed in 1997 as Denmark's renewable energy island and has been the site for many energy innovations which are leading the island to be fossil fuel free by 2030 [56]- [58]. Today, the annual energy demand balances the annual supply from RES (sometimes the island produces more electricity than it consumes owing to offshore and onshore wind power, and a district heating based on biomass) but the island is currently not self-sufficient, yet.…”

Enhancing the self‐resilience of high‐ renewable energy sources, interconnected islanding areas through innovative energy production, storage, and management technologies: Grid simulations and energy assessment

“…Other tools, such as EnergyPlan, Homer, or RETScreen, are representative of one node models [30] and cannot be used for complex systems, similar studies and/or cannot provide similar results with this level of detail as they have many limitations in network representation, Energy Management Systems (EMS) control customization, and solver capabilities [23], [31]. Similar works in Samsø and Orkney have been performed using EnergyPlan [1], [32], but due to certain capabilities of this software, they refer to a conceptual-design level of detail. The present work intends to provide a higher level of detail, while being in position to calculate key power related variables (not only electricity, but also heating/cooling ones).…”

Large-scale solar district heating plants in Danish smart thermal grid: Developments and recent trends

“…One study showed that the technical and private economic aspects of integrating a large capacity of electric driven heat pumps in the Greater Copenhagen district heating system, which is an example of a state-of-the-art large district heating system with many consumers and suppliers [93]. Heat pump combined with heat storage utilizing wind power locally was also demonstrated in [94] . It is also showed excess heat from industrial thermal processes within 5 km by 5 km Danish Square Grid in Denmark [95].…”