Barriers and opportunities to maximize the share of solar thermal energy in district heating networks – approaches within the IEA SHC Task 55, Subtask A and selected preliminary results
Abstract
The integration of large and very large solar thermal plants in district heating (DH) networks gained increasing attention in recent years. However, the integration poses some challenges, especially for large shares of solar heat. This contribution gives an overview of the approach chosen within subtask A of the IEA SHC Task 55 for assessing the impact of high shares solar thermal energy on the overall district heating and cooling network and different integration aspects in order to maximize the share of solar thermal energy. This is including • The collection and analyses of case studies for assessing the technical requirements of large shares • The economic analyses of overall DHC networks, their supply strategies, transition strategies, heat demand and energy price scenarios • Analyses of DHC network hydraulics, evaluation of hybrid technologies and possible supply points for large solar thermal installations • Overall DHC network control strategies and other measures for increasing solar thermal fractions This contribution describes the used approach and selected preliminary results Keywords: solar district heating; case studies; integration aspects; transition strategies; network performance; hydraulics; control strategies; return temperature reduction.