A Case study: Optimizing the district heating network of Amsterdam by implementing Thermal Storage

Abstract

In the Dutch ”Warmte transitie,” district heating is set to play a predominant role, with the goal of achieving gas-free domestic heating by 2050. This necessitates upgrading traditional district heating networks to the fourth generation. To support this transition, the potential of decoupling heat production and demand through thermal storage is explored. A technoeconomic case study on the district heating network of Amsterdam-East/Almere evaluates the value of heat storage. The literature study concludes that, given the current supply temperatures and financial objectives, heat should be stored as sensible pressurized heat. The transition period between 2030 and 2040 is modeled, focusing on shifting from fossil based to power-to-heat-oriented district heating networks. A diverse asset configuration is implemented, providing affordable heat at low and medium electricity prices. The objective is to quantify the influence of thermal storage and its impact on asset dispatch dynamics. This study addresses a gap in the literature by providing a fundamental description of a diverse asset configuration transitioning towards a power-to-heat-based district heating network. A numerical model using linear programming, specifically a combination of dual simplex and barrier methods, is employed. The main input variables are based on long-term commodity price forecasts. A rolling optimization horizon is implemented to focus on mid/short interval storage optimization, acknowledging the unrealistic nature of perfect forecasts. Non-linearity in the Combined Heat and Power (CHP) systems is managed by pre-defining state points within the operational domain. Additional constraints such as start-up costs, subsidies, and carbon taxes are included. The correlation between increasing storage capacity and financial benefits appears logarithimic, primarily due to limited overcapacities in favorable power-to-heat assets. During the transition, the value of storage capacity diminishes due to rapidly decreasing operational costs, reducing the absolute value of Thermal Energy Storage (TES). Optimizing CHP dispatch generates significant value, attributed to its non-linear price formation. The transition shifts value generation from winter to summer months due to changes in overcapacity. The hybrid model, which optimizes both financial and environmental benefits, shows no significant decrease in carbon footprint but helps stabilize it while increasing financial gains, this is visualised with a Pareto front plot. The new generation district heating networks with limited overcapacity can benefit significantly from small-scale heat storage capacity. For this specific network, an optimal storage capacity of 1600 MWh has been identified. Additionally, it is concluded that incorporating storage capacity enhances dispatch flexibility and provides resilience against future uncertainties