Design and Development of Wind-Solar Tree: A Hybrid Renewable Energy System for Domestic Applications

Wind and solar are the two renewable sources available abundantly in the nature. Presently solar energy is in use for domestic applications in most of the urban and rural areas. However, the availability of the solar energy will be during the day time and maximum during the summer season only. During the night and also during the monsoon and winter seasons the solar systems may not fulfil the energy requirement. On the other hand, wind will be steady with better velocity during the night and with higher velocity during the monsoon and winter seasons. Therefore, to generate the electric energy day and night throughout the year a rooftop hybrid wind-solar systems are better for domestic applications. In this direction in the present work, a compact and low-cost wind-solar tree of 500 W capacity is proposed. A metallic structure in a tree shape is installed with micro-wind turbines and solar panels. Savonius micro-wind turbines each with 100 W capacity at a wind velocity of 12 m/s are designed and fabricated. These turbines are coupled with low torque axial flux permanent magnet generators. Four number of polycrystalline solar modules each with 40 W capacity are used in this work. Wind turbines and the solar panels are mounted in a pattern on the metallic tree structure to harness the renewable wind and solar energy more effectively. From performance study it is observed that the wind turbines at wind velocity of 8.2 m/s produced total 75 W of power and on a sunny day the solar modules produced 126 W power at 14 Hrs of a day. It is also observed that in combined operation of wind turbines and solar modules the wind-solar tree produced 210 W power at 11 Hrs of a day.