This thesis is part of a research project about a novel type of absorption chiller, the Thermo Chemical Accumulator (TCA), an invention patented by Solsam Sunergy AB, Sweden. The work was done at the Solar Energy Research Centre (SERC) in Bor-länge, Sweden, in cooperation with Solsam Sunergy AB and Vattenfall Energi. The aim of the project was to make a simulation model of the system and further make simulations with the model. The model of the TCA was made based on measurements made on a prototype TCA-system. First a crude model of the TCA was made in a spreadsheet application and this was then implemented in TrnSys. In TrnSys the TCA-model was expanded to include a building as cooling load, solar thermal collector as driving heat source, cooling coils as outside coolers and weather data readers for simulating different cli-mates. Parametric studies were made to find out the performance of the system. The main parameters varied were: load type (office/domestic), collector size, outside cooler size, air conditioning unit size and storage size. It was found that the sizing of the air conditioning unit has a critical influence on the cooling output of the system; in the TCA the outlet cooling temperature depend on the ambient temperature and commercial air conditioning units are usually dimen-sioned for temperatures lower than the available outlet temperatures from the TCA during hot days. The outside coolers were found to be of sufficient size. The storage size was not found to limit the solar fraction. But as only short term storage was stud-ied, the conclusion holds only for this case. The COP of the system was found to be around 0.65 with steady state operation or short term storage, which is a normal value for current absorption refrigeration technologies.