Energy and Sustainability Notes- February 18th

Introduction to Electricity and Energy Generation

• Early concepts of electricity involve generating current through motion in a magnetic field.

Electromagnetic Induction

• Continuous rotation of a coil in a magnetic field induces electric voltage and current.

• The current produced is alternating current (AC), which alternates direction.

Characteristics of AC

• Current is strongest when the conductor is perpendicular to the magnetic field lines (right angles).

• As the coil continues rotation, the induced current decreases as fewer magnetic lines are crossed.

• No current flows when the conductor is parallel to the field.

• Each rotation results in two instances of no current and fluctuating direction of current flow.

Construction of Direct Current Sources

• To maintain current flow in one direction (direct current or DC), a commutator is used instead of slip rings.

• The commutator rectifies AC to DC by switching connections as the coil rotates.

• The practical use involves multiple coils to minimize pulsations and provide a steady voltage.

Discovery of Electromagnetic Principles

• Faraday's laws indicate that moving magnets can also generate current through wires, emphasizing the movement of electrons in conductive materials.

• Conventional current flows opposite the direction of electron movement.

Electromagnetism and Current Flow

• When electricity flows through a wire, it creates a magnetic field; reversing the current reverses the magnetic field.

• Coiling the wire increases the strength of the magnetic field.

• A magnet passing through a coil induces current; this current alternates with the motion of the magnet.

Generation of AC Current

• Fast magnet movement or stronger magnets generate stronger current, as does using larger coils with more turns.

• Rotating magnets around fixed coils achieves efficient energy generation.

• Current characteristics can be plotted, resulting in a sine wave pattern indicative of ongoing AC flow.

Multi-Phase Power Generation

• Adding more coils at different angles (e.g., 120 degrees) allows for multiple phases, leading to more consistent power flow.

• Phased systems ensure that at least one coil always provides current, making energy utilization higher.

Water as a Resource for Power Generation

• Water's unique properties (phase changes) make it an excellent energy carrier.

• Thermal energy from water can be harnessed, leading to steam power applications.

History of Steam Power

• Early steam engines converted heat energy from combustion (often coal) into mechanical energy.

• Improvements in engine design, like precise boring machines, enhanced efficiency.

Steam Engine Mechanics

• Power strokes achieved through careful temperature management and pressure control within cylinders.

• Continuous improvements allow for greater pressure and steam efficiency which contributed to the industrial revolution.

Innovations in Motion Mechanics

• Rotational motion is more advantageous than linear for various applications. Mechanisms such as crankshafts enable this conversion.

• Flywheels stabilize and smooth output, reducing vibrations in engines.

The Role of Early Electricity Generation

• The fusion of thermal systems and electricity generation led to the establishment of power plants.

• Edison's early power plants utilized direct current to supply energy.

Competition Between Tesla and Edison

• Rivalry grew between Tesla's alternating current systems and Edison's direct current systems.

• Westinghouse's collaboration with Tesla led to the development of significant hydroelectric projects, like at Niagara Falls.

Conclusion

• Advancements in both thermal efficiency and electrical generation paved the way for modern power systems.

• Understanding these principles is crucial for appreciating contemporary energy production methodologies.