01 The conceptual design of the photovoltaic solar thermal collector hybrid system and the ground source heat pump to provide electricity, heating and cooling a residential building focusing on technical, economic and environmental parameters.

This paper attempts to present and compare four solar assisted ground source heat pump combined systems with series and parallel layouts and direct and indirect heat exchange in Zahedan in order to supply part of the electricity demand for equipment and selling surplus electricity to the grid as a source of project financing and revenue generation for residents, moreover, fulfill the region's need for access to natural gas. In the first step, the energy need for a residential building on the 94-square-meter plan with common building materials of the region is designed for a family of four in Design builder software and the hourly heat needed for a year is calculated. Design, modeling and performance control of each proposed system in Polysun software is conducted with utilizing 25 solar photovoltaic-thermal collectors with a total area of 33.25 square meters and 2 vertical geothermal heat exchangers in 100 meters depth. And all four plans are evaluated and compared after supplying energy of the building in terms of the amount of energy consumption, heat pump performance coefficient, the amount of produced electricity and CO2 emissions. The maximum and minimum values of the performance coefficient among the plans for direct heat exchange and series systems are 4.39 and 3.87, respectively , the optimal plan is introduced with 4957 kWh electricity consumption and 10667 kWh electricity production. The period of return on capital is estimated for 7 years. Due to the environmental impacts of fossil fuels and due to environmental assessment, the designed system will prevent 5089/7 kg CO2 emissions annually. The results indicate that the proposed optimal plan for exploiting in the south and southeast of Iran will have economic and environmental benefits.