JEC installed the first grid-connected hybrid solar and wind turbine system for the Kowloon Hospital, a public hospital in Hong Kong. The system takes full advantage of solar and wind power. Electricity can be generated when there is sun or wind. When there is neither sun nor wind, the hospital can draw electricity from Hong Kong’s conventional power grid, thus maintaining a stable supply of electricity.
The Hybrid System Design
The system consists of 108 solar photovoltaic panels and two Vertical-Axis Wind Turbines (VAWT). The system’s annual energy output is about 29,000 kWh, which saves around 22,620 kg of Carbon Dioxide. The photovoltaic panels were arranged to fully utilise the roof space. A site condition assessment was carried out at the design stage and VAWT turbines were built on the edge of the roof so that they did not take up valuable space needed for the photovoltaic panels.
Benefits of VWAT over HWAT
In comparison with traditional Horizontal-Axis Wind Turbines (HWAT), VWAT can capture all wind directions without needing directional adjustments and also avoids other adverse effects: VWATs require less wind to function, emit less noise, less vibrations, and do not harm wildlife (birds can be injured by HWAT).