On the Reliability of Small-Scale Solar System: Design of a stand-alone system in rural countries
Tid: Ti 2019-09-24 kl 13.15 - 14.00
Plats: Ivar Herlitz, Teknikringen 33, Plan 3 rum 2306
Föreläsare: Abeer Mrad
Over one billion people in the world suffer from energy poverty. A Large share of people who don’t have access to electricity live in the Sub-Saharan, African region, and are spread in rural and remote locations. Connecting these people to the national grid is a great challenge in terms of cost and time. Thus, off-grid is the suitable solution to limit the energy poverty in rural area, especially when the location is far from the grid. The use of renewable energy resources is gaining more attention and more off-grid systems are operated and installed since they supply environmentally friendly and cost-effective energy. However, designing reliable off-grid systems based on renewable energy is challenging due to the stochastic nature of these resources. Moreover, one of the main challenging in off-grid implementation in rural areas is that the consumption increases every year which makes it extra challenging to design a system that is not oversized and at the same time cover the increased need of electricity.
The focus of this thesis was on a small-scale photovoltaic off-grid system. The conducted case study was in an energy kiosk, in rural community in Zambia. The main objectives were to study the existed system design and to suggest new design alternatives for the system when it’s time to be expanded, assuming that the load increases 5% per year for the first 10 years of the system execution. The suggested design alternatives were, further, investigated in terms of reliability and life cycle cost. The used design methodology suggested new design for the system with similar PV unit’s capacity but doubled battery bank capacity. However, testing these results in a reliability model results in that the suggested design will have more than double Loss of Power Supply Probability (LPSP) than the existed system. This result was taken into consideration to create new design options for the system to maintain the initial system reliability. One optional design suggests increasing the capacity of the PV unit with 25 % in order to maintain the initial system level of reliability.