Defence of dissertation in the field of energy efficiency and system engineering, Hassam ur Rehman, M.Sc. (Eng)

Feasible utilization of solar thermal energy to meet the heat demand in the Nordic countries.
Solar energy

The public examination of the doctoral dissertation of Hassam ur Rehman, M.Sc. (Eng), will be held on 17 December 2018 at 12.00 at the Aalto University School of Engineering. The title of the dissertation is Techno-economic performance of community sized solar heating systems in Nordic conditions. Field of the dissertation is energy efficiency and system engineering, solar energy, buildings and HVAC.

Energy use in the buildings forms a major part of the Finland’s energy consumption. Efficient houses and renewable energy, in particular solar energy, are considered to be some of the solutions to fight against climate change. The challenge in the Nordic condition is the mismatch between the production and consumption of the solar energy, making it uneconomical.

The objective of the thesis is to design, optimize and compare several solar thermal district heating architectures for the community in the Nordic climate, based on the techno-economic performance. The dissertation uses simulations to design cost-optimal and energy-optimal solar district systems for the communities. It proposes many new optimized solar district heating systems, and also analyzes the failures of such systems in real conditions.

The thesis found that the solar energy could be made feasible in Finland by focusing on the community scale solutions, rather than single building solutions. The district scale solutions reduce the costs due to the economy of scale and by sharing the losses and by lowering the peak energy demand. Moreover, integration of the seasonal storage and efficient buildings with the solar energy generation allows the utilization of solar energy during winters when the heating demand is highest. Such concepts can minimize the import of the electricity and the costs, and maximize the technical performance.

The results also showed that the decentralized energy systems can be better both technically and economical compared to the centralized systems. The outcomes of this thesis can contribute towards the practical design of the solar district systems in the Nordic countries. This dissertation is relevant to the building and energy systems designers, businesses related to the sustainability, urban planners and energy-policy makers.

Opponent: Professor Per Kvols Heiselberg, Aalborg University, Denmark.

Supervisor: Professor Risto Kosonen, Aalto University, School of Engineering, Department of Mechanical Engineering

Electronic dissertation:

Doctoral candidate’s contact information: Hassam ur Rehman, [email protected], +358 46 9055270

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