Use cases with economics and simulation for thermo-chemical district networks

Abstract

Thermo-chemical networks using absorption and desorption to capture and valorise the potential of very low-grade residual heat (20 °C to 60 °C) to offer a reduction of end user costs and increased primary energy efficiency. The paper demonstrates the technical and economic potential of thermo-chemical networks by defining use cases and their related level of energy efficiency and technological feasibility. Furthermore, specific economic scenarios, including estimations on investment and operation costs, demonstrate the economic benefit of the technology. Simple payback periods between about 0.5 and 7.5 years indicate a good economic feasibility with end user costs below 4 €ct/kWh-equivalent and refunds of 0.5 to 1 €ct/kWh for the required residual heat. Due to the low-temperature characteristics of the relevant systems and services, detailed simulations are required to approve the functioning and viability of the new technology. For this purpose, the paper demonstrates the simulation outline using the example of space heating based on a low-temperature air heating system partially driven with thermo-chemical fuel.