Development of Optimization Strategies for a Wind-Solar Hybrid system: A Case Study of ST. Francis Xavier Girls Secondary School in Naivasha, Kenya

Abstract

Hybrid power systems are some of the remedies used as an alternative source of energy in Kenya. An integration of wind- solar hybrid systems for energy supply is viewed as a key element of alternative technology. Wind and solar are some of the considerable renewable energy options, both at present as well as in the future due to their availability. Hybrid systems are becoming more convenient ways of harvesting energy from renewable sources when two or more technologies are incorporated and used as one. This study focused on analyzing the performance and development of optimization strategies of a Wind-Solar hybrid system, based on site parameters in St Francis Xavier School Naivasha. The system consists of two wind turbines 900 W each, 30 solar PV modules 100 Wp each arranged into 3 strings of arrays. The system was meant to meet the power load demand in the School. However, power from grid was being used despite the huge investment in renewable energy system. Data on power peak load and power generated from wind and solar PV system was collected by use of data logger for a period of three months. Analytical methods and tool such as Microsoft excel and Hybrid Optimization Model for Electric Renewable software (HOMER) were used for analysis; data was presented in form of bar graphs and curves to give a precise meaning of results. It was found that daily energy demand was 40.5 kWh. Monthly solar energy harnessed was; 98.86 kWh, 94.31 kWh and 120 kWh in February, March and April 2016 respectively. In conclusion, adding 3 kWp solar power and harmonizing the load distribution among three inverters were the best optimization strategies that can be adopted. The findings of this study will be used in future as the reference to estimate available and extractable power from solar and wind power systems as source of renewable energy yearly.