THE CURIOUS CASE OF DISTRICT HEATING COST STABILITY
II. Multi-Source Heat Cost Optimization Principles The basic steps for minimizing heat costs in district heating systems are: A. Determine the annual heating demand. B. Identify locally available heat sources. C. Identify importable energy vectors. D. Assess the capital expenditure (CAPEX) and operating expenditure (OPEX) of potential heat plants. E. Determine the most suitable mix of heat generation tech- nologies concerning CAPEX, OPEX, and heating demands being fulfilled. A. Determine the annual heating demand. This article assumes we are designing a 100 MW district heat- ing system to supply an annual demand of 333 GWh. Figure 1 shows the annual heat demand curve (left) and the same annual demand sorted in descending order, commonly called a duration curve (right). The load figures clearly show that the system will run on a part load for a large part of the year. The aim of the utility is to design the heat generation to allow cost-effective heat supply at any given heat demand or time.
B. Identify locally available heat sources. To ensure the highest operational stability of the system, it is of
Figure 1. Annual heating demand (left) and demand duration curve (right).
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