Using a STEEP model to optimize Solar Home Systems in Bangladesh

Bangladesh has experienced significant energy shortfalls in the electrical grid since at least 2005 and the majority of people living outside urban areas do not have access to electricity. Solar energy is an attractive form of supplemental electrical energy. One approach to implementing solar electric energy systems in Bangladesh is the Solar Home System (SHS), an off grid Photovoltaic (PV) solar energy system. With over 3 million solar home systems already installed, it is an increasingly important component of rural energy. The SHS as it currently exists only enables limited loads, such as lights and televisions, is relatively expensive and has some significant technical issues. This research study attempts to explore how distributed PV can be improved, using Bangladesh as a case study. Literature is reviewed to determine interactions and elements of distributed PV systems. A quantitative Social, Technological, Economic, Environmental and Political (STEEP) index is developed. A software program called poplar is developed to evaluate the existing Solar Home System using the proposed STEEP index. This is compared to an alternative topology incorporating distributed energy storage elements into loads to provide flexibility and scalability in system usage and reliability. The developed model simulation indicates that implementing distributed energy storage elements allows reduction of PV module and storage size. While there is significant uncertainty in the cost and environmental impact of the power electronics, this smaller sizing is correlated with total reduction in system price and environmental impact. The conclusion to this study is that the current SHS configuration may be better optimized by incorporating distributed energy storage into the loads