Segments in this Video

Part A: Introduction (02:24)


Heat energy is usually a byproduct of energy transformation. Efficiency measures how much useful energy you get out of something. Incandescent light bulbs only transform 2% of energy into light; LED transform 20%.

Part B: Power (in Watts) (05:21)

Watts (w) express power, the amount of energy transformed per second, and are equivalent to joules/second. Carbohydrates burn faster than fat in humans. Learn about inefficient incandescent light bulbs.

Part C: Improving Efficiency (06:15)

Learn about incandescent and LED bulb history. Compare efficiency, power and light output in incandescent, fluorescent and LED bulbs. Sankey diagrams show energy input and output in devices; companies are trying to improve solar panel efficiency.

Part D: Heat Wastage and Energy "Loss" (09:09)

Plants convert light energy to chemical energy with 1-2% efficiency. Car engines are about 25% efficient; excess kinetic energy transforms to heat energy while braking. Humans are also 25% efficient. Learn about energy "loss" through bouncing ball and trampoline examples.

Part E: Efficiency in Nature and Industry (06:34)

Learn about the role of ligaments, calf muscles, and Achilles tendons in producing spring and contributing to human long distance running capacity. View efficiency in different species and in airplane design. Hear how to improve heat transfer efficiency in water.

Credits: Shedding Light on Energy: Episode 3—Energy Efficiency (00:37)

Credits: Shedding Light on Energy: Episode 3—Energy Efficiency

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Shedding Light on Energy: Episode 3—Energy Efficiency

Part of the Series : Shedding Light on Energy
DVD (Chaptered) Price: $129.95
DVD + 3-Year Streaming Price: $194.93
3-Year Streaming Price: $129.95



In this program, we introduce students to the concept of efficiency, which is a measure of how much useful energy you get out of something compared to the amount of energy that you put into it. We answer a bunch of questions including: How much light energy do we get out of light globes compared to the amount of electrical energy that goes into them? Hint: it’s not much; they should be called heat globes! How much kinetic energy do we get out of cars compared to the amount of chemical energy that we put into them? Hint: it’s a bit more, but not that much more! And how do our arched feet make us the long-distance running champions of the animal world? This video is the most energy-efficient way of learning everything that you need to know about energy efficiency!

Length: 31 minutes

Item#: BVL147631

ISBN: 978-1-64347-244-7

Copyright date: ©2018

Closed Captioned

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