Research Database

This paper studies an optimal design of grid topology and integrated photovoltaic (PV) and centralized battery energy storage considering techno-economic aspect in low voltage distribution systems for urban area in Cambodia. This work aims at searching for an optimal topology including size of the battery energy storage by two different methods over the planning study of 15 years. Firstly, the shortest path algorithm (SPA) and first-fit bin-packing algorithm (FFBPA) are used to find out the topology which minimize the line and the load balancing. Secondly, mixed integer quadratically constrained programming (MIQCP) algorithms are developed to search for a topology which minimize conductor use and the load balancing improvement. Next, Genetic algorithm is developed to size the maximum PV peak power connected into LV network with respected to voltage and current constraints. Then, the size of battery energy storage procedure is established in order to eliminate the reverse power flow going on medium voltage (MV) grid and to improve the autonomous operation time of system. A discounted cost method is used to evaluate the solutions for different methods. Lastly, an urban area in Cambodia is chosen as a case study in this paper. Simulation results confirm the proposed method in this research.

This study quantifies the environmental burdens created by a planned rooftop photovoltaic (PV) solar installation on a university campus in Bangkok, Thailand, and models the potential of rooftop solar to meet the country’s renewable energy goals. Impacts are evaluated using Life Cycle Assessment and recommendations made for upstream purchasing decisions according to different scenarios. Results indicate that main contribution to impacts occurs in manufacturing by stage and from PV modules by component. Impacts generated by the mounting structure and inverters are also significant, and together these components constitute over 90% of environmental burdens. A climate change impact of 0.079 kg CO2-eq/kWh is produced over the lifetime of the system. Energy Payback Time is calculated as 2.5 years, and the Economic Payback Period is 7.4 years. The system is estimated to avoid 1.00E+06 kg CO2-eq over its lifetime. Installation of similar rooftop PV systems on 50% of university and government buildings in Bangkok could result in a net reduction of 4.80E+09 kg CO2-eq. Domestic production of components and recycling of materials is identified as a best-case scenario, with alleviations across all impact categories. Economic analysis suggests on-site electricity consumption paired with a net-metering policy scheme is the best way to incentivize PV solar energy installations.