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Speaker 1: Stuff happens, just don't let it happen to your photos, music,

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Speaker 1: and documents. Protect your important files with Mosey by e

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Speaker 1: m C, the most trusted name and cloud backup. Save

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Speaker 1: ten percent today with promo code brain Stuff at mosey

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Speaker 1: dot com. That's m o z Y dot com. Welcome

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Speaker 1: to brain Stuff from how Stuff works dot com where

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Speaker 1: smart happens. I am Marshall Brain with today's question, what

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Speaker 1: are all the different ways to store energy? Besides using

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Speaker 1: rechargeable batteries. Human beings have been looking for a good

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Speaker 1: way to store energy for a long time. One of

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Speaker 1: the big things that's been holding up electric cars is

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Speaker 1: battery technology. When you compare batteries to gasoline, the differences

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Speaker 1: are huge. For example, a typical electric car might carry

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Speaker 1: a thousand pounds of lead acid batteries. Those batteries take

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Speaker 1: several hours to recharge, and they might give the car

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Speaker 1: a hundred mile range. Two or three gallons of gasoline

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Speaker 1: give the same range. Weigh less than thirty pounds, and

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Speaker 1: you can pump that much gasoline in about a minute.

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Speaker 1: There's really no comparison between gasoline and batteries. Here's a

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Speaker 1: list of some of the other technologies that people commonly

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Speaker 1: use to store energy. Some of these working electric car

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Speaker 1: while others are better off for stationary applications. One of

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Speaker 1: the oldest techniques people have used is the falling weight.

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Speaker 1: You lift the weight to store the energy in it,

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Speaker 1: and then you let the weight fall to extract the energy.

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Speaker 1: Many grandfather clocks and cuckoo clocks use this technique. By

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Speaker 1: running the string attached to the weights through a gear train,

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Speaker 1: you can use a heavy weight and let it fall

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Speaker 1: over a long period of time. This approach doesn't work

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Speaker 1: very well in an electric car, but it's worked well

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Speaker 1: in clocks for hundreds of years. Many power plants use

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Speaker 1: the falling weight approach in the form of water. The

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Speaker 1: water is pumped uphill to a lake at night when

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Speaker 1: the power plant has excess capacity, and then during high

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Speaker 1: demand daytime periods, the water runs through a termite on

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Speaker 1: its way downhill to a lower lake. Another way to

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Speaker 1: store energy is in some form of repeatable mechanical deformation.

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Speaker 1: This is the idea behind a spring used in a

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Speaker 1: wind up clock or a rubber band used in a

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Speaker 1: wind up airplane. You store the energy by deforming the

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Speaker 1: material in the spring and the material releases that energy

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Speaker 1: as it returns to its original shape. At the scale

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Speaker 1: of a car, this technology has problems because of the

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Speaker 1: weight of the spring, but it's smaller scales like a

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Speaker 1: wrist watch, it works great. Nature has been storing energy

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Speaker 1: for a long time, and if you want to think

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Speaker 1: about it this way, gasoline is really a form of

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Speaker 1: stored natural energy. Plants absorbed sunlight and turn it into

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Speaker 1: carbohydrates over millions of years, those carbohydrates can turn into

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Speaker 1: oil or coal, and that's a form of stored energy.

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Speaker 1: On a more human time scale, we burn wood to

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Speaker 1: release stored energy stored in the plant, or we turn

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Speaker 1: corn into alcohol and burn the alcohol. Another technique that

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Speaker 1: nature uses the store energy is fat, which many of

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Speaker 1: us are familiar with in a personal way. It's interesting

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Speaker 1: to think about a car that somehow eats grass or

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Speaker 1: some other form of carbohydrate and stores it is fat.

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Speaker 1: You can take energy and split water into its hydrogen

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Speaker 1: and oxygen atoms using electrolysis. By storing the hydrogen, you

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Speaker 1: can later create energy by burning it or by running

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Speaker 1: it through a fuel cell. You can use energy to

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Speaker 1: spin up a flywheel and then later extract the energy

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Speaker 1: by using the flywheel to run a generator, or you

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Speaker 1: can store heat directly and later convert the heat to

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Speaker 1: another form of energy like electricity. Molten salt is one

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Speaker 1: way to do this. You can use compressed air to

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Speaker 1: store energy, or you can compress air a lot and

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Speaker 1: get something like liquid nitrogen and use the liquid nitrogen

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Speaker 1: to power a car. One of the new technologies that

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Speaker 1: may become available in the future involves antimatter. When you

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Speaker 1: combine matter with antimatter, you get energy. You can store

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Speaker 1: energy by creating anti matter. Right now, none of these

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Speaker 1: techniques can hold a candle, which is really another form

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Speaker 1: of stored energy, to gasoline in the convenience sense. Fuel

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Speaker 1: cells look to be the closest competitor right now, and

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Speaker 1: they'll probably become available to the general public over the

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Speaker 1: next few years. For more on this and thousands of

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Speaker 1: other topics, is it how stuff works dot Com. Your photos,

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Speaker 1: music and documents are irreplaceable. Protect them with Mosey by

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Speaker 1: e m C, the most trusted name and cloud back up.

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Speaker 1: Back up your files today and save ten percent with

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Speaker 1: promo code. Brain Stuff at Mosey dot com, m o

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