Framework design of an off-grid remote 3-bedroom house using solar DC power system

The utilization of renewable energy power systems is currently gaining widespread popularity with the increase of energy demand and concerns on the carbon dioxide emission to the environment that will cause global warming. Malaysia has move forward by promoting used of renewable energy such as solar PV to the public where it generated locally at a distribution voltage level. Presently there is growing interest in employing DC as a means of delivering power to the load due to its numerous advantages in comparison to AC. Furthermore, since the electricity generated by a solar PV system is in DC, the totally DC system will contribute to the overall simplicity of the system design. Nevertheless, literature reviews reveal that there is a broad variety of design approaches and assumptions employed in various research studies, resulting in significant variability. In addition, numerous approaches have been identified in economic analysis. Therefore, it is crucial to develop a uniform set of design principles and procedures, together with an economic structure, for the design aspects of DC system. Therefore, the objective of this study is to improve the framework design of an off-grid solar PV system house using solar DC power system to achieve the 100% renewable energy fraction and fulfilling the annual load demand. The load will be a 3-bedroom residential house that consumed within the smallest energy consumption band which is 200 kWh per month. The processes involved are project site selection, residential load profiling, design calculation, verification of the designed system through PVsyst and Homer simulation for technical and economic performance and lastly prototype development. The design process for a technical aspect has been performed by deploying design calculations, which were subsequently validated through the use of PVsyst simulation. Then, a techno-economic analysis of a solar PV power system was conducted utilizing the Homer Pro software. Finally, the procedure of designing and developing a prototype known as the DC power module for the purpose of distributing energy to a fully DC-powered residential building. Based on the results obtained, both methods which are design calculations and have PVsyst simulation exhibited nearly identical results hence it can be concluded that both methodologies are feasible in ascertaining the most effective configuration for a solar PV power system. For the techno-economic analysis utilizing Homer Pro software, the solar PV DC system demonstrates lower initial cost and LCOE compared to the solar PV AC system. However, in terms of LCOE value, is comparatively higher when compared with the grid tariff rate to users consuming 200 kWh. In addition, DC power module has been successfully designed and developed for distribution of DC power to a fully DC residential. This prototype can provide electricity to both high-power and low-power loads using both of its 48 V DC and 12 V DC output with the maximum power nearly 1,600 W. Lastly, in terms of environment, this design set-up is expected to benefit the residential consumers in reducing utility electricity consumption up to 2,434 kWh per year which is equivalent to almost 1.7 tons of carbon emissions avoidance into the environment annually.