Energy Laws of thermodynamics

Think, Write, Pair, Share Have you ever thought about how difficult it would be to get ready for school in the dark? Or how hard it would be to do homework at night if you had no light? Electricity is pretty important for us to get through every day life. How is electricity generated?

What is Energy? Work needed to move matter and the heat that flows from hot to cooler samples of matter. – Mechanical, electromagnetic, electrical, chemical, nuclear energy Kinetic Energy Moving Energy Wind, flowing streams, electricity (flowing electrons) Potential Energy Stored energy and potentially available for use Unlit match, still water behind a damn, chemical energy stored in gas molecules.

Energy Quality High Quality Energy Concentrated Performs much useful work Electricity, chemical energy stored in coal and gasoline, concentrated sunlight, nuclei of uranium-235 Low Quality Energy Dispersed Little ability to do useful work Heat dispersed in moving molecules of a large amount of matter (atmosphere, ocean)

Laws of Thermodynamics 1 st Law In all physical/chemical changes, energy is neither created nor destroyed. Energy can be converted from one form to another. Energy input=Energy output 2 nd Law Whenever energy changes from one form to another, some useful energy is always degraded to lower quality, more dispersed, less useful energy. The degraded energy is now in the form of lost heat (not reusable)

Energy Efficiency Measure of how much useful work is accomplished by a particular input of energy into a system. Lesson: the cheapest and quickest way to get more energy is to stop wasting almost half the energy we use. How can we stop wasting energy?

How is Electricity Traditionally Generated? 1.Steam/gas is produced by burning a fossil fuel such as coal/natural gas 2.The stem/gas moves across the blades of a large turbine creating mechanical energy. 3.A rod is connected to the turbine causing large magnets surrounded by coils of copper wire to spin. 4.This creates a large magnetic field around the coils. Electrons begin to flow in the wires. 5.Electrons=Electricity

Coal Burning Power Plant

Other Ways to Generate Electricity Nuclear Power Hydroelectric Power Wind Power Solar Power Biomass (most is used for heat, not electricity)