Exploiting waste heat potential by long distance heat transmission: Design considerations and techno-economic assessment

Harvesting the waste heat from industrial processes or power plants is a very effective way to increase the efficiency of an energy system. Available usually as low-grade heat, it needs to be transferred to the points of consumption in order to be utilized. Feasible heat transmission distance is usually estimated by empiricism or by considering a limited number of parameters with the lack of a methodological tool to estimate this distance based on actual generic data. This work analyzes the particularities of long distance heat transmission by using a detailed techno-economic model for the estimation of heat transport costs including all relevant capital and operating expenditures. Sensitivity analysis is conducted to show the effect of transmission distance, supply temperatures and market prices, covering the most common technical and economic parameters found in literature. This model is also used to identify the maximum economically feasible transmission distance that meets a specified economic criterion and to derive a 'rule of thumb' equation.