Location-aware solar simulation and sizing tool for solar home systems.

Abstract

The development of reliable solar home systems that ensure the power supply never goes off for a given period (days of autonomy) is one of the primary goals in solar system design yet the current options for solar system design have no protocol to demand what reliability the user expects. An optimal solar panel size that delivers sufficient energy for a given period is important for a highly reliable solar home system. The traditional technique of sizing solar photovoltaic (PV) panels involves the use of a blanket value of the expected hours of solar radiation in a given area and balancing it with the total load wattage. This does not take into consideration the microclimates which can cause similar systems to have different reliability performance when located in the same climatological zone. There is thus a need to improve the solar panel sizing methodology for these systems. This report proposes the use of actual observed solar radiation data for a home environment and battery state of charge. In this project, we use the insolation data over one year for the region and generate the load profile for the home for this same period by categorizing the loads into day and night-time loads. We then use these curves to determine the energy balance of the home over the period, the state of charge of the battery, and eventually the reliability of the system for a given panel size. Furthermore, we determine an approximate total cost of the system by summing the cost of the panel, battery, charge controller, inverter, and cabling which increases as the panel-size and reliability of the system increase. Our software, therefore, provides a solution to determine the reliability and total cost of a given size of the panel and battery and thus can be used to determine the optimal size of the panel and battery for particular reliability and total cost.