The rise in population causes serious issues in larger cities since the electrical grid is becoming overloaded. Simultaneously, the demand on more sustainable energy production and the use of renewable energy sources increase. Renewable energy based off-grid electrical systems are a possible solution to decrease the magnitude of these issues. The purpose of this thesis is to compare solar cells, solar thermal collectors and PVT (Photovoltaic thermal hybrid solar collectors) and design the most suitable combination of solar panels for a selfsufficient multi-family house in Jönköping, Sweden. The solar panels were compared from a cost and energy production perspective, then a suitable renewable energy system with all three types of panels was constructed and optimized using Opti-CE, which is a MATLABbased software. During the course of this thesis, an interview was made with Hans-Olof Nilsson who is a co-founder of Nilsson Energy and owner of a self-sufficient off-grid house. The results show that PVT-panels have higher energy production per area and 22% higher LCC (life cycle cost) than regular solar cells in combination with solar thermal collectors. Optimization results indicate that the house cannot be self-sufficient by installing solar panels on the given roof area only, rather the area of installed solar collectors should be increased to a minimum of 1497𝑚2 . With the given roof area of 900𝑚2 the house can only be self-sufficient a maximum of 75% of the time. The results also indicate that the introduction of compact systems with the simultaneous decrease of cost will make renewable off-grid energy systems more attractive in the future.

It is known that Sweden is categorised by being one of the regions that experience low solar radiation because it is located in the northern hemisphere that has a low potential of solar radiation during the colder seasons. The government of Sweden aim to promote a more sustainable future by applying more renewable initiative in the energy sector. One of the initiatives is by applying more renewable energy where PV panels will play a greater role in our society and in the energy sector. However, the produced energy from the PV panels is unpredictable due to changes in radiation throughout the day. One great way to tackle this issue is by combining PV panels with different energy storage system. This thesis evaluates an off-grid rowhouse in Eskilstuna Sweden where the PV panels are combined with a heat pump, thermal storage tank, including batteries and hydrogen system. The yearly electrical demand is met by utilizing PV panels, battery system for short term usage and hydrogen system for long-term usage during the colder seasons. The yearly thermal demand is met by the thermal storage tank. The thermal storage tank is charged by heat losses from the hydrogen system and thermal energy from heat pump.The calculations were simulated in Excel and MATLAB where OPTI-CE is composed with different components in the energy system. Furthermore, the off-grid household was evaluated from an economic outlook with respect to today’s market including the potential price decrease in 2030.The results indicated that the selected household is technically practicable to produce enough energy. The PV panels produces 13 560 kWh annually where the total electrical demand reaches 6 125 kWh yearly (including required electricity for the heat pump). The annual energy demand in terms of electricity and thermal heat reaches 12 500 kWh which is covered by the simulated energy system. The overproduction is stored in the batteries and hydrogen storage for later use. The back-up diesel generator does not need to operate, indicating that energy system supplies enough energy for the off-grid household. The thermal storage tank stores enough thermal energy regarding to the thermal load and stores most of the heat during the summer when there are high heat losses due to the charge of the hydrogen system. The simulated energy system has a life cycle cost reaching approximately k$318 with a total lifetime of 25 years. A similar off-grid system has the potential to reduce the life cycle cost to k$195 if the energy system is built in 2030 with a similar lifespan. The reduction occurs due to the potential price reduction for different components utilized in the energy system.