| || || Prasad, Shivneel.|
| || || Solar-wind hybrid system : optimal design for a small load requirement |
Institution: University of the South Pacific.
Call No.: pac In Process
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: Pacific Island Countries (PIC’s) have a huge potential renewable energy to cater for their energy needs. This vast amount of energy can be captured directly as solar radiation or indirectly from wind or by hybridising the two. It is important that research be carried out in PIC’s to study solar and wind resources to design and implement efficient and economical renewable systems. This project was carried out at the University of the South Pacific Campus, Suva to study solar and wind resources in order to design and implement a solar-wind hybrid system to light up dark areas around the student recreational area. Resource analysis showed that on average the site received 3.8 kWh m-2 day-1 of solar energy with 1387 full sun hours annually. Monthly average wind speeds of 3.88 m s-1 10 m above ground level was obtained which when extrapolated to 15 m (the hub height of the wind turbine) showed average wind speed was 4 m s-1 with power density of 70 W m-2. With this wind resource, a Whisper 100 wind turbine would be in operation for approximately 50% of the time in the year. The complementary nature of solar and wind resources showed good potential for a solar-wind hybrid system. WAsP’s analysis and prediction of the annual energy production (AEP) from the wind turbine showed that the site had an AEP of 556 kWh using a Whisper 100 with the most prominent wind direction being from the south east. RETScreen software indicated that approximately 90 kWh of renewable energy could be harnessed using a single Sharp 120 Wp PV module. HOMER design and optimization of the hybrid system showed that the most optimum solution at the site was a hybrid with 120 WP PV module combined with a Whisper 100 wind turbine and 400 Ah of total storage at 12 V. Manual calculations were similar to that predicted by HOMER. This system was constructed in April, 2009 and monitored for three months. In these three months of operation, the system was 3.24% efficient with the Whisper 100 having an efficiency of 27% and a capacity factor of 3% while the PV module was estimated to be 12.1% efficient as stated by the manufacturer. Economical analysis of the hybrid system was carried out considering a system lifetime of 20 years. The cost of energy (COE) from the hybrid was FJ$ 1.23 per kWh. However, this cost is 5 times greater then the FEA tariff with a simple payback period of four times that of the system lifetime.