Research Papers

These challenges arise from the geography of the city, as well as the costs of renewable energy.
The limited land space that Hong Kong has to offer is a weakness in itself in relation to reaching net zero coal by 2035.
Offshore wind speeds can be more stable and faster than onshore turbines leading to more energy creation (The pros, 2021). However, offshore wind turbines can be expensive, maintenance can be complex
Within the last few years, China has invested a lot in offshore winds and in 2020 6.1GW of offshore wind was installed, and China was the leader (World, 2021). .
The International Renewable Energy Agency has estimated that electricity created from renewable energies will be cheaper than that made from the newest, most inexpensive coal plants (Majority, 2021).
Lastly, Gao et al. (2019), mention the capability to place small wind turbines on top of 65m or higher buildings.
Once there is enough reliable renewable electricity generation to meet HK final consumption demands, the introduction or compliment of batteries and even green hydrogen can begin, which will eventually be a major component in the replacement of oil.

Even with different Solidity, the Slender VAWTs with Higher Aspect Ratios are better in performance than Wider VAWTs (lower Aspect ratios.
The higher the solidity, we got the maximum performance early at a lower Tip speed ratio. which allows us to get VAWTs with low RPM which means low noise levels.
Increasing the AR to about 10 results in superior performance. The predicted maximum Cp is near the Betz limit.
Increasing the number of blades has a tiny effect on the maximum Cp but it helps in getting lower TSR at Cp, max.

The lighter rotors are much better than heavier ones. specifically, at low wind speeds where lower starting torque is needed to overcome the moment of inertia MOI.
There is an optimum number of blades that perform well without increasing the rotor weight too much.