Seasonal storage of solar energy for self-sufficient buildings with focus on hydrogen systems

摘要

The main topic of this dissertation is seasonal storage of solar energy for buildings. The dissertation focuses on solar hydrogen systems as stand-alone energy systems for low energy dwellings. This has been a simulation study, where the models have been developed for TRNSYS and used in simulations. A description of the models developed for the components used in solar hydrogen systems has been made. These models are of electrolyzers, fuel cells, pressurized tanks, metal hydride tanks, photovoltaic cells, batteries and converters. The models of the photovoltaic cells, the electrolyzer and the battery have been validated. The sizes of the loads for a low energy dwelling are discussed. A distribution of the loads over the year and day has been assumed. These assumptions and estimates are the basis for the simulations where the goal in this work is to cover all of these demands with the energy system. The possibilities and requirements for a solar hydrogen system for an energy self-sufficient dwelling are discussed mainly on a technical basis. Economic factors are also considered. Rules of thumb and simulation approach for estimating the sizes of the components for the solar hydrogen system have been suggested. A parameter study has been done to find the sizes of possible systems that could cover the energy demand of a low energy dwelling. If there is a reduced load, another climate, or a hybrid system with for example wind power or hydropower, the required size of the energy system could be reduced. 69 refs., 56 figs., 18 tabs.