In recent years, due to the gradual increase in prices of petroleum products and thereby transport costs, there are more and more alternative forms of transport. The largest share consists of smaller electrical vehicles such as bicycles, scooters, carts ... Overall the sales of electric bicycles increased dramatically in recent years, as they are now more accessible, cheaper and more efficient. They can also be used by older people and those who usually have problems riding normal bicycles or just want some help and a lighter ride.
Often there is also the idea, that we could use the mechanical energy of people by riding a bicycle, stationary bike, devices in the gym or some other device and use produced electricity to earn money or recover some investment costs.
In this thesis we will focus on these two problems by building our own fully functional electric bicycle and use it to measure the energy produced while pedaling.
We chose a standard mountain bike and transformed it into an electric bicycle with the help of a dedicated in-wheel electric motor with controller and battery. We used the motor in the rear wheel of the bicycle. While building the electric bicycle we encountered some minor construction problems but at the end we successfully resolved them all.
The result was a very useful electric bicycle with which we could reach speeds up to 30km/h on electric power alone and driving range of around 30km without additional assistance.
Completion of electric bike was followed by measurements in the laboratory. For this we used generator mode of the in-wheel motor. Using a bicycle stand and digital oscilloscope we measured current and voltage while pedaling and also calculated the energy produced.
We have found out that the average human can produce power of about 200W, or even up to 600W or more for a short period. However, economically speaking, sales/use of electricity produced by pedaling does not pay off in any way considering the current price of electricity and the price of the investment. In the best-case scenario we would need to run the bike for 8 hours every day for around 14 years to recover the cost of our initial investment.