As fossil fuel usage has been proven to have a negative impact on human health and the environment, the world has embraced the usage of renewable energy sources, mainly for energy production. In Cyprus, solar energy is the most potent renewable source and this can be seen by the vast majority of the population using solar water heaters in their households. This thesis explores the usage of solar energy for electricity and domestic hot water production at a residential level by presenting the designs of three solar-thermal concept systems for achieving this task; the first being the basic design of all three without any form of storage, the second is fitted with thermal latent heat storage and the third is fitted with a natural gas boiler instead. The optimal solution is the second concept system that is capable of storing thermal energy around the year thus having a nearly uninterrupted operation, reducing the dependency on fossil fuel produced electricity and emissions. The thesis also explored the usage of siloxane organic compounds as working fluids for a low temperature Rankine cycle, which had a significant impact in the increase of the thermal-to-electrical efficiency of the cycle, raising it to nearly 25%, greater than the efficiency of best acclaimed photovoltaic collector currently available. Lastly, taking into account a typical household's demand profile and by allowing the optimal system to operate as part of the national electrical network continuously, the size of the system's components could be reduced significantly making it more feasible for installing in a typical household's premises. However, due to the non-existence of these components in the within the project's specifications, the thesis could not include a useful economic analysis for a more realistic comparison with a similar sized photovoltaic system.