Choose the incorrect statement regarding wind power.

Options

A. It is expected to harness wind power to minimum in open space
B. The potential energy content of wind blowing at high altitudes is the source of wind power
C. Wind hitting at the blades of a windmill causes them to rotate. The rotation thus achieved can be utilised further
D. One possible method of utilising the energy of rotational motion of the blades of a windmill is to run the turbine of an electric generator.

Explanation

To solve the question of identifying the incorrect statement regarding wind power, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Wind Power**:
Wind power is generated by converting the kinetic energy of wind into mechanical energy using wind turbines. This mechanical energy is then converted into electrical energy by generators.

**Hint**: Remember that wind power relies on the movement of air (wind) to generate energy.

2. **Analyzing Option A**:
"It is expected to harness wind power to maximize in open space."
- This statement is correct because wind turbines are typically placed in open areas where wind flow is unobstructed, maximizing energy capture.

**Hint**: Think about where you would find the most consistent and strong winds.

3. **Analyzing Option B**:
"The potential energy content of wind blowing at high altitude is the source of wind power."
- This statement is also correct. Wind at higher altitudes tends to have greater potential energy due to higher speeds and less turbulence.

**Hint**: Consider how altitude affects wind speed and energy.

4. **Analyzing Option C**:
"Wind hitting at the blades of windmill causes them to rotate. The rotation thus achieved can be utilized further."
- This statement is correct as well. The kinetic energy of the wind causes the blades of the turbine to rotate, which is essential for generating electricity.

**Hint**: Focus on the mechanics of how wind turbines operate.

5. **Analyzing Option D**:
"One possible method of utilizing the energy of rotational motion the blades of windmill is to run turbine of an electric generator."
- This statement is incorrect. The term "rotational motion" is misleading in this context. The blades of the windmill do not create rotational motion; rather, they create mechanical energy that drives the generator. The correct term should be "mechanical energy" rather than "rotational motion."

**Hint**: Pay attention to the terminology used in describing the energy conversion process.

### Conclusion:
The incorrect statement regarding wind power is **Option D**.