### Introduction

Power from the wind has become an increasingly popular option for electricity generation. Unlike traditional energy sources such as coal, oil, and gas that contribute large quantities of carbon dioxide to the atmosphere, wind power relies on a non-polluting, renewable, ever-present  resource—the wind. In recent years, the cost of harnessing energy from the wind has become more affordable making it a viable alternative for many communities.

A wind turbine generally consists of a three-bladed propeller made of fiber and resin composite materials mounted on the top of a tall tower. It converts energy from the mechanical energy of moving air to electrical energy by means of a generator. The wind causes the shaft of the turbine to spin which in turn causes a generator to produce electricity.

In this experiment, you will measure the power output of a wind turbine, investigate the relationship between power output and wind speed, and design and test your own wind turbine blades.

You will use a small motor as a generator and cardboard blades as the turbine. The power output of the turbine can be determined by measuring the current and voltage produced by the motor. Power is determined using the relationship

$P = VI$ ${\text{Power}} = {\text{voltage}} \times {\text{current}}$

### Objectives

• Use an energy sensor to measure power output.
• Calculate power output.
• Determine the relationship between power output and wind speed.
• Determine the relationship between power output and blade shape.