WEBVTT Kind: captions Language: en 00:00:00.040 --> 00:00:03.705 Do you know how much power the stuff in your life uses? 00:00:03.705 --> 00:00:05.617 Great! 00:00:05.617 --> 00:00:08.176 Except that doesn’t matter. 00:00:08.176 --> 00:00:17.955 I’m actually quite serious - knowing how much power in watts your devices use can be helpful and it does matter in some circumstances, 00:00:17.955 --> 00:00:25.187 but it’s usually nowhere near as important to your life as how much energy those things use. 00:00:25.187 --> 00:00:29.719 This may sound like one of those overly pedantic fixations but it’s not! 00:00:29.719 --> 00:00:34.018 Power and energy are very different concepts. 00:00:34.018 --> 00:00:37.841 They are closely linked, but that’s not the whole story. 00:00:37.841 --> 00:00:46.163 And unfortunately, the units we use to discuss power and energy can be very confusing if you’re not well-versed in energy speak. 00:00:46.163 --> 00:00:51.870 However, if you can wrap your head around precisely how power and energy influence each other, 00:00:51.870 --> 00:00:56.937 I promise a whole lotta stuff in your life gets much easier to understand. 00:00:56.937 --> 00:01:05.893 Now, you might think I’m going to start by discussing electricity but before we get there I want to instead talk about this. 00:01:05.893 --> 00:01:08.961 This is a bottle of liquid propane. 00:01:08.961 --> 00:01:13.714 When sold in this kind of bottle it’s commonly used as a camping fuel. 00:01:13.714 --> 00:01:21.209 The propane has energy stored in its chemical bonds, and we can release that energy by allowing the propane to leave the bottle, 00:01:21.209 --> 00:01:28.125 vaporize, and mix with the atmosphere which creates an air/fuel mixture with a good deal of free oxygen. 00:01:28.125 --> 00:01:34.487 And when we ignite that mixture it burns - a chemical reaction known as combustion. 00:01:34.487 --> 00:01:40.550 The useful byproduct of that combustion is heat, the most basic form of energy. 00:01:40.550 --> 00:01:48.250 Devices which burn propane in a controlled fashion are how we make use of the propane’s stored energy. 00:01:48.250 --> 00:01:51.466 Devices such as this camping stove. 00:01:51.466 --> 00:01:54.615 The stove itself is incredibly simple. 00:01:54.615 --> 00:02:04.752 Other than its overall physical structure, it’s little more than a pipe which leads to a pair of valves which then feed nozzles inside these two burner elements. 00:02:04.752 --> 00:02:12.224 Connect a propane bottle up to that pipe using this very flimsy and precarious pressure-regulating hookup tube thingamijig 00:02:12.224 --> 00:02:17.841 and once you’ve done that opening those valves will allow some of the propane to leave the tank, 00:02:17.841 --> 00:02:22.989 after which it goes through the nozzles and ends up in the burners where it mixes with air. 00:02:22.989 --> 00:02:33.042 Press this ignitor button which strikes a piezo-electric crystal in order to produce  a spark near where the propane/air mixture exits the burners and fwoomp. 00:02:33.042 --> 00:02:34.857 You’ve got fire! 00:02:34.857 --> 00:02:37.853 And now you can cook your delicious whatever. 00:02:37.853 --> 00:02:44.492 Hmmm… but how much delicious whatever are you able to cook with that bottle of propane? 00:02:44.492 --> 00:02:49.308 That’s a good question - and its answer has to do with energy. 00:02:49.308 --> 00:02:53.782 Remember, we are burning the propane to release its energy. 00:02:53.782 --> 00:02:57.967 Since we can only burn it once and then it disappears into the atmosphere, 00:02:57.967 --> 00:03:04.853 the quantity of propane in the bottle represents the total amount of heat energy that’s available to us. 00:03:04.853 --> 00:03:11.766 When new and full, that bottle contained one pound of liquid propane (that’s 453 grams). 00:03:11.766 --> 00:03:15.838 But that’s it - when it runs out it runs out. 00:03:15.838 --> 00:03:23.720 Now, when it comes to figuring out how much we can do with a bottle of propane, there’s what might seem like a complication. 00:03:23.720 --> 00:03:29.760 If you’ve used any kind of stove before, you’ll know that we don’t always use them in the same way every time we cook. 00:03:30.361 --> 00:03:39.447 Sometimes we might need to boil a big pot of water but on other occasions we might need to do gentler kinds of cooking, such as simmering. 00:03:39.447 --> 00:03:46.840 To address those varying needs, the valves on the stove can release the propane from the bottle at different rates. 00:03:46.840 --> 00:03:54.325 Watch - as I close the valve down and slow the rate of fuel flow, the flame shrinks and isn’t as hot. 00:03:54.325 --> 00:04:03.411 This lets us do those gentler cooking tasks by introducing a limit to how hot a piece of cookware can possibly get when sitting above the flame. 00:04:03.411 --> 00:04:12.201 But when I set the valve to its wide-open setting, the rate of fuel flow increases so the hotter (and larger) the resulting flame is. 00:04:12.201 --> 00:04:14.496 You can even hear that difference. 00:04:15.278 --> 00:04:18.548 [a roaring/hissing noise grows louder and quieter] 00:04:18.548 --> 00:04:22.270 And just what exactly is that difference? 00:04:22.270 --> 00:04:24.463 It’s power. 00:04:24.463 --> 00:04:33.846 Through adjusting the rate of fuel flow, the valves adjust the power level of the burners and thus the size and heat of their resulting flames. 00:04:33.846 --> 00:04:41.694 Critical to note is that power is NOT how much propane is in the bottle or even how much we’ve burned. 00:04:41.694 --> 00:04:49.594 Instead, power is how *quickly* we are burning through the propane and releasing its energy at any given moment. 00:04:49.594 --> 00:04:58.782 Power, therefore, represents an instantaneous energy intensity,  which is not the same thing as energy itself. 00:04:58.782 --> 00:05:01.298 Why is that so important? 00:05:01.298 --> 00:05:06.304 Well, because energy is what actually accomplishes work. 00:05:06.304 --> 00:05:14.736 Getting things done, like bringing water to a boil or cooking a piece of chicken, requires a certain amount of energy. 00:05:14.736 --> 00:05:22.131 You can actually calculate how much energy it takes to bring, say, six cups of room temperature water to a boil. 00:05:22.131 --> 00:05:24.869 That's just a fact of physics. 00:05:24.869 --> 00:05:36.602 And we also know how much energy the propane contains per gram, so we can work out precisely how much propane we’ll have to burn to boil six cups of water. 00:05:36.602 --> 00:05:40.120 I won't go through that calculation, but it’s on your screen now. 00:05:40.120 --> 00:05:46.294 And if we assume half of the energy released by the stove will actually make it into the water in a pot 00:05:46.294 --> 00:05:52.787 (a lot of heat from an open flame ends up going around a pot so there are pretty heavy losses to consider) 00:05:52.787 --> 00:05:59.543 then we’ll find that to produce the necessary heat energy  to boil six cups of water on this stove, 00:05:59.543 --> 00:06:02.781 we need to burn about 20 grams of propane. 00:06:02.781 --> 00:06:05.811 That’s roughly 5% of a full bottle. 00:06:05.811 --> 00:06:08.401 So, here’s the key question: 00:06:08.401 --> 00:06:12.392 does it matter what power level we have the burner is set to? 00:06:12.392 --> 00:06:16.761 Aside from marginal efficiency effects, no it doesn’t. 00:06:16.761 --> 00:06:19.430 20 grams is 20 grams. 00:06:19.430 --> 00:06:22.281 That’s how much propane we’re gonna use. 00:06:22.281 --> 00:06:26.377 How quickly we burn it doesn't matter. 00:06:26.377 --> 00:06:31.188 And yet, here’s where things can start to get confusing. 00:06:31.188 --> 00:06:38.612 When it comes to how you and I interact with our energy resources, time absolutely matters. 00:06:38.612 --> 00:06:47.074 In fact, time is the key to understanding what power is and how it relates to energy consumption. 00:06:47.074 --> 00:06:52.189 Consider that the stove doesn’t allow us to burn all of this propane in an instant. 00:06:52.189 --> 00:06:58.389 If it did, we wouldn’t be burning it so much as we’d be exploding it. 00:06:58.389 --> 00:07:08.143 We don’t want that so the stove limits how quickly the propane  can leave the bottle and thus it limits how quickly we can release its heat energy. 00:07:08.143 --> 00:07:16.734 The fastest rate at which this stove will let us burn propane on each of these two burners is about 3.8 grams per minute. 00:07:16.734 --> 00:07:21.384 And believe it or not that right there is a power figure! 00:07:21.384 --> 00:07:29.548 It’s a very weird one,  but 3.8 grams of propane per minute does indeed accurately describe this power level. 00:07:29.548 --> 00:07:35.690 Remember, power, at a conceptual level, is how quickly we are using energy. 00:07:35.690 --> 00:07:38.764 And since the propane is our energy resource, 00:07:38.840 --> 00:07:46.049 a figure which tells us how much we burn over a  given period of time describes power. 00:07:46.049 --> 00:07:53.851 Of course, grams of propane per minute is not a conventional power unit, but let’s think about what it can tell us. 00:07:53.851 --> 00:07:59.342 While it may not be easy to predict  how much propane a cooking task will require, 00:07:59.342 --> 00:08:05.673 since we know we burn through 3.8 grams of propane every minute the burner is set to high, 00:08:05.673 --> 00:08:13.723 then if we know how long we’ve been using that burner on high power, we can actually determine how much propane was burned. 00:08:13.723 --> 00:08:19.540 It's simply a matter of taking that power figure and multiplying it by the total run time. 00:08:19.540 --> 00:08:28.585 So, for example, using one burner on max power for a total period of 10 minutes will tell us that we used 38 grams of propane: 00:08:28.585 --> 00:08:32.335 3.8 grams per minute for 10 minutes. 00:08:32.335 --> 00:08:41.995 The upshot is that power figures, when runtime is also known, give us enough information to determine how much energy was used. 00:08:41.995 --> 00:08:52.071 Of course, we don’t typically use grams of propane per minute but the thing is, every power unit is describing the same thing: power. 00:08:52.071 --> 00:08:54.503 So you can convert between them. 00:08:54.503 --> 00:08:58.879 This power level is also 4.3 horsepower. 00:08:58.879 --> 00:09:01.708 Or 11,000 BTU/hr. 00:09:01.708 --> 00:09:05.087 Or not quite one ton of refrigeration. 00:09:05.087 --> 00:09:08.350 Or, the power unit you’re probably most familiar with, 00:09:08.350 --> 00:09:11.830 3,200 watts. 00:09:11.830 --> 00:09:16.373 Yes, in case you weren’t aware the watt is not exclusive to electricity. 00:09:16.373 --> 00:09:18.454 The watt is power! 00:09:18.454 --> 00:09:24.907 It can mean electrical power, but it can also mean heat output or mechanical power. 00:09:24.907 --> 00:09:29.025 Doesn’t everybody know 1 horsepower is 746 watts? 00:09:29.396 --> 00:09:38.865 Of course, we usually reference the watt in the context of electrical devices so I guess we should transition to talking about electricity. 00:09:38.865 --> 00:09:43.436 First, though, what exactly is the watt? 00:09:43.436 --> 00:09:44.686 Simple! 00:09:44.686 --> 00:09:48.964 One watt is equivalent to one joule per second. 00:09:48.964 --> 00:09:57.492 Now, okay, the joule is a unit of energy but don’t worry, you don’t actually need to know what exactly the joule is, 00:09:57.492 --> 00:10:00.952 you just need to know it’s a specific quantity of energy. 00:10:00.952 --> 00:10:06.813 And how many joules of energy get used in one second is… watts. 00:10:06.813 --> 00:10:08.998 It’s that simple. 00:10:08.998 --> 00:10:16.431 Note to physicists: I am aware of the conservation of energy and that saying “joules which get used” is not technically correct but 00:10:16.431 --> 00:10:20.510 this video is to help people understand how they use energy resources. 00:10:20.510 --> 00:10:22.613 So please just roll with it. 00:10:22.613 --> 00:10:29.388 Now, since watts represent the number of joules used per second then just like in the stove example, 00:10:29.388 --> 00:10:36.710 if you know how many watts a device needs to function and you have a record of how long the device has been functioning 00:10:36.710 --> 00:10:45.081 you will be able to determine precisely how many joules (and thus how much energy) that device actually used during that time. 00:10:45.081 --> 00:10:50.588 However, joules are teeny tiny little bits of energy. 00:10:50.588 --> 00:10:56.285 A ten watt light bulb consumes 600 joules every minute. 00:10:56.285 --> 00:11:01.698 Now the good news is, just as power is power, energy is energy! 00:11:01.698 --> 00:11:09.944 There are many different units we can use to quantify energy but they all describe the same thing so we can convert between them. 00:11:09.944 --> 00:11:12.557 When we’re talking about electrical energy, 00:11:12.557 --> 00:11:17.692 because the joule is really tiny and most people don’t have much feel for what a joule is anyway, 00:11:17.692 --> 00:11:22.496 we usually use a unit of energy called the watt-hour. 00:11:22.496 --> 00:11:29.240 Watt-hours are what they sound like: it is simply power in watts multiplied by the total runtime in hours. 00:11:30.080 --> 00:11:33.189 The result you get is watt-hours. 00:11:33.189 --> 00:11:42.059 So, for example, that same 10 watt light bulb, after running for three hours, will consume 30 watt-hours of energy. 00:11:42.059 --> 00:11:47.051 10 watts times 3 hours equals 30 watt-hours. 00:11:47.051 --> 00:11:48.637 Quite simple. 00:11:48.637 --> 00:11:56.436 And, just for funsies, since there are 3,600 seconds in an hour that means there are 3,600 joules in a watt-hour, 00:11:56.436 --> 00:12:02.164 so 30 watt-hours is equal to 108,000 joules. 00:12:02.164 --> 00:12:05.615 Perhaps you see why we don’t usually use joules. 00:12:05.615 --> 00:12:16.003 But unfortunately, although the watt-hour is a very simple concept and it’s very simple to calculate, it can be a little confusing if you’re not used to it. 00:12:16.003 --> 00:12:27.005 “Watt-hours” sounds dangerously close to “watts per hour,” and that might land in your brain as a speed at which we use watts. 00:12:27.005 --> 00:12:33.677 But the thing you’ve gotta keep in mind about the watt is that the watt itself is a rate. 00:12:33.677 --> 00:12:36.832 It’s literally joules per second, after all, 00:12:36.832 --> 00:12:40.806 so in a sense the watt is a speed. 00:12:40.806 --> 00:12:43.199 A speed of energy. 00:12:43.199 --> 00:12:51.572 To actually quantify an amount of energy from the watt, we need to know how long we've been running at that “speed.” 00:12:51.572 --> 00:12:59.875 The hour, in watt-hour, allows us to determine the product of a known rate in watts and an hour’s time. 00:12:59.875 --> 00:13:06.214 This means the watt-hour is both a calculation that derives energy from power and time 00:13:06.214 --> 00:13:10.011 and the result of that calculation. 00:13:10.011 --> 00:13:15.391 That’s, I think, what makes it confusing if you’re not well-versed in energy speak. 00:13:15.391 --> 00:13:20.489 Not only can it seem pretty clunky to quantify energy as a calculation, 00:13:20.489 --> 00:13:30.000 but the terminology watt and watt-hour is linguistically backwards compared to how we typically describe rates and quantities. 00:13:30.400 --> 00:13:37.360 Usually when we see a time component in a unit,  like miles per hour or revolutions per minute,   00:13:37.360 --> 00:13:42.629 we are describing a rate by saying what will get done in that time period. 00:13:42.629 --> 00:13:50.405 But because the watt itself is a rate (joules per second) it stands on its own. 00:13:50.405 --> 00:13:57.480 Much like a speed reading can’t tell you a distance traveled without knowing how long you’ve been traveling at that speed, 00:13:57.480 --> 00:14:03.827 the watt can’t describe a quantity of energy  unless we add the total time to the mix. 00:14:03.827 --> 00:14:06.924 And that’s the point of the watt-hour. 00:14:06.924 --> 00:14:14.010 And although it can seem clunky, the watt-hour is incredibly useful to understanding energy 00:14:14.010 --> 00:14:19.130 because it brings the time part of this whole deal front and center. 00:14:19.130 --> 00:14:24.395 For instance, say you’ve got a television which uses 150 watts of power. 00:14:24.395 --> 00:14:31.128 If you want to know how much energy it uses, you need to know how long you’ve been watching TV! 00:14:31.128 --> 00:14:37.836 After you’ve been watching for two hours, your TV will have consumed 300 watt-hours of energy. 00:14:37.836 --> 00:14:45.183 It’s simply the 150 watts the TV uses when it’s on multiplied by its runtime of 2 hours. 00:14:45.183 --> 00:14:46.843 Watt-hours. 00:14:46.843 --> 00:14:48.416 Pretty simple. 00:14:48.416 --> 00:14:54.939 When we’re dealing with time intervals smaller than an hour, you multiply by the fractional hour. 00:14:54.939 --> 00:15:01.123 For instance, to calculate the energy used by the same TV in 15 minutes, a quarter of an hour, 00:15:01.123 --> 00:15:11.492 simply multiply 150 watts by one fourth of an hour, or 0.25 hours, and that gives us 37.5 watt-hours. 00:15:11.492 --> 00:15:21.613 It’s a simple calculation, and hopefully you see how it works kind of like a tally system which adds to the energy total the longer your devices draw power. 00:15:21.613 --> 00:15:32.582 Since we've all got a lot of devices that need more than one watt of power, in practice we usually use the kilowatt-hour which is simply 1,000 watt-hours. 00:15:32.582 --> 00:15:35.207 Just makes the numbers smaller. 00:15:35.207 --> 00:15:45.034 And if you were to look at your electricity bill, you will find that you were billed for the total number of kilowatt-hours you consumed during that billing period. 00:15:45.034 --> 00:15:53.150 And remember, I’m gonna be a bit obnoxious about this, that means you were billed for the total amount of energy you consumed. 00:15:53.150 --> 00:16:01.007 Whenever you see the word “hour” after the word watt, or in an abbreviation the letter h after the letter W, 00:16:01.007 --> 00:16:04.477 then you are looking at a quantity of energy. 00:16:04.477 --> 00:16:06.882 Not a power figure. 00:16:06.882 --> 00:16:13.051 And when it comes to your energy bills, energy is the only thing that matters! 00:16:13.051 --> 00:16:23.181 For electricity bills there is an asterisk there which I’ll get back to, but most residential electric bills are not impacted by the power draw of your home. 00:16:23.181 --> 00:16:28.786 They are only impacted by your home's total energy use in kilowatt-hours. 00:16:28.786 --> 00:16:38.119 This is crucial to understand because if you’re not in an energy-first mindset,  it’s easy for power figures to mislead you. 00:16:38.119 --> 00:16:47.383 For instance, something that I’ve run across again and again pretty much every time I’ve talked about electric cooktops - induction or conventional - 00:16:47.383 --> 00:16:53.812 is this idea that electric cooking is wildly expensive compared to gas cooking. 00:16:53.812 --> 00:16:57.323 Now, there is some logic to why people say that: 00:16:57.323 --> 00:17:03.353 in general, methane gas is a less expensive source of heat than electricity is. 00:17:03.353 --> 00:17:12.495 And electric cooktops do indeed need to be hooked up to beefy 40 or 50 amp circuits because they can draw a lot of power. 00:17:12.495 --> 00:17:20.355 If all the burners on my stove at home are set to high, the stove draws 8,500 watts. 00:17:20.355 --> 00:17:24.579 That’s a scary big number and is indeed quite a lot of power, 00:17:24.579 --> 00:17:28.113 but power isn't what matters to your energy bill! 00:17:28.113 --> 00:17:30.113 Energy is! 00:17:30.113 --> 00:17:36.438 And the thing about household cooktops and ovens  is that when it comes to a typical home’s energy use, 00:17:36.438 --> 00:17:39.031 they’re practically rounding errors. 00:17:39.031 --> 00:17:43.265 Think for a moment about what cooking is. 00:17:43.265 --> 00:17:49.304 It's simply heating food. And, yes, sometimes it makes things very hot 00:17:49.304 --> 00:17:53.514 But you’re only making small things very hot. 00:17:53.514 --> 00:18:02.664 That heat, even though it is often intense, is very concentrated and this ultimately means it’s not actually a large amount of energy. 00:18:02.664 --> 00:18:05.624 And remember that whole time thing? 00:18:05.624 --> 00:18:11.186 Unless you’re running a restaurant out of your home, you only use your stove for a couple hours a day, 00:18:11.186 --> 00:18:14.962 likely less if you’re not an adventurous cook. 00:18:14.962 --> 00:18:27.519 But if your home is climate controlled, then you’ve got a machine which is running 24/7 to maintain the temperature of a much larger object than tonight’s dinner. 00:18:27.519 --> 00:18:37.161 To give you some actual numbers, my home’s air conditioner is a little 2 ton unit which only draws about 2 kilowatts (that’s 2,000 watts) when it’s running. 00:18:37.161 --> 00:18:44.090 But during the height of summer, that thing will run for somewhere between 6 and 12 hours each day. 00:18:44.090 --> 00:18:53.351 Taking a low average of 8, this means my air conditioner is responsible for about 16 kilowatt-hours of energy use per day. 00:18:53.351 --> 00:18:56.171 How does that compare to my stove? 00:18:56.171 --> 00:19:01.663 Well, to give you a specific example of how much energy an actual cooking task needs, 00:19:01.663 --> 00:19:05.977 sometimes I scramble three eggs in a small pan like this. 00:19:05.977 --> 00:19:10.762 And when I do it, I use one of my stove’s small, 1,200 watt burners. 00:19:10.762 --> 00:19:16.274 It takes the stove maybe 2 minutes to pre-heat the pan enough to melt a pad of butter in there 00:19:16.274 --> 00:19:21.573 and once I put the eggs in and start scrambling they’re usually done within five or six minutes. 00:19:21.573 --> 00:19:27.361 Now, typically I reduce the power level of the burner once they’re starting to firm up but to make the math easier 00:19:27.361 --> 00:19:32.379 we’ll just pretend that I run that burner on full power for the entire 8 minutes. 00:19:32.379 --> 00:19:35.635 So, how much energy does that use? 00:19:35.635 --> 00:19:48.649 Well, that’s 1,200 watts (or 1.2 kilowatts) multiplied by 8/60ths of an hour which results in 0.16 kilowatt-hours of energy. 00:19:48.649 --> 00:19:51.440 That is nothing! 00:19:51.440 --> 00:19:56.375 Literally just 1% of what my air conditioner uses in a day. 00:19:56.375 --> 00:19:59.348 And as far as how much that energy costs, 00:19:59.348 --> 00:20:08.399 even with a horrendous electric rate of $0.50 per kilowatt hour,  it would only cost about 8 cents to scramble those eggs. 00:20:08.399 --> 00:20:16.680 With my electric rate which averages around $0.10 per kilowatt-hour, it doesn’t even cost the $0.02 an opinion is worth. 00:20:16.680 --> 00:20:24.395 Uh, quick note - I calculated these numbers based  on my guess of how long it typically takes to scramble eggs with my stove 00:20:24.395 --> 00:20:27.556 and I overestimated by a lot! 00:20:27.556 --> 00:20:37.523 I like my eggs very dry and despite that the total time spent, including heating the cold pan, was only 5 minutes 15 seconds. 00:20:37.523 --> 00:20:45.499 I also turned the burner down to half-power at the 2:45 mark meaning that the actual energy expenditure here 00:20:45.499 --> 00:20:52.212 was approximately 0.08 kilowatt-hours or 80 watt-hours. 00:20:52.212 --> 00:20:54.885 It’s a tiny amount of energy. 00:20:54.885 --> 00:21:01.983 Just the lava lamps in my set used more energy  in the time it took to shoot this video. 00:21:01.983 --> 00:21:07.028 Now, granted, scrambling three eggs is not much of a cooking task. 00:21:07.028 --> 00:21:16.789 But even the most energy-intensive cooking tasks like boiling  huge quantities of water don’t require that much energy in the context of a home. 00:21:16.789 --> 00:21:26.739 Assuming a 25% loss, it takes about 2 kilowatt-hours to bring four gallons of water to a boil on an electric stove. 00:21:26.739 --> 00:21:32.633 So even if you do that every day, the 60 kilowatt-hours that would require over a month 00:21:32.633 --> 00:21:39.729 would only represent about 6.5% of the average US household’s monthly electricity consumption. 00:21:39.729 --> 00:21:46.236 People who fixate on the cost to use an electric stove frankly just don’t understand energy. 00:21:46.236 --> 00:21:49.226 Or they’re peddling culture war nonsense. 00:21:49.226 --> 00:21:53.862 Now, to be clear, I’m not trying to sing the virtues of electric cooking. 00:21:53.862 --> 00:22:00.880 What I’m really hoping to help you understand here is the importance of having an energy-focused mindset. 00:22:00.880 --> 00:22:06.550 Power figures in watts rarely matter, energy does. 00:22:06.550 --> 00:22:13.032 And if you put energy front and center in your mind, not only will it help you understand your electric bill 00:22:13.032 --> 00:22:21.172 but it can bring you a more specific understanding of precisely why the machines in your life cost what they cost to operate. 00:22:21.172 --> 00:22:24.688 I really want to encourage you to spend some time thinking about this. 00:22:24.688 --> 00:22:29.932 Energy doesn’t have to be a mystery, and if you can develop an intuition for it 00:22:29.932 --> 00:22:37.765 then you’ll have a much better grasp of the opportunities available to you with the infrastructure in your home and the challenges, too. 00:22:37.765 --> 00:22:40.980 And it’s time to drop a truth bomb. 00:22:40.980 --> 00:22:50.316 There is in fact just one single most important factor to determining how much energy you use and it's almost comically simple: 00:22:50.316 --> 00:22:53.177 it’s what you do. 00:22:53.177 --> 00:22:59.703 It’s not actually complicated, it’s the stuff you do in a day that determines how much energy you use. 00:22:59.703 --> 00:23:05.822 Every time you ask a machine to complete a task for you, it takes a certain amount of energy. 00:23:05.822 --> 00:23:11.757 And if you don’t have any idea how much energy certain tasks require, you can figure that out! 00:23:11.757 --> 00:23:19.537 One option is to use a plug-in energy monitor like this which will not only give you a reading of how many watts a device is currently drawing 00:23:19.537 --> 00:23:24.414 but will also tell you a cumulative energy consumption in kilowatt-hours. 00:23:24.414 --> 00:23:27.935 And once you have that answer, now you know! 00:23:27.935 --> 00:23:32.364 It’s always gonna take the same amount of energy to do the same thing. 00:23:32.364 --> 00:23:37.253 If you don’t have one of these things handy, you can use the power rating of the machines you’re using, 00:23:37.253 --> 00:23:45.173 which they usually list somewhere on them, and how long you need to use them to complete the task in order to give you some idea. 00:23:45.173 --> 00:23:56.158 But you have to be careful with that - power labels and runtime don't always provide the best answer since many devices don’t consume a consistent amount of power. 00:23:56.158 --> 00:24:01.442 I mean, sure my stove has a label on it which tells me its maximum power draw, 00:24:01.442 --> 00:24:09.667 but its actual power draw depends on what burners I’m using and the power levels those individual burners are set to. 00:24:09.667 --> 00:24:15.929 The area where power labels can trip you up the most is when you’re looking at a machine which is always in use. 00:24:15.929 --> 00:24:24.396 A refrigerator, for instance, will tell you its maximum current draw in amps which you can multiply by the incoming voltage to determine watts, 00:24:24.396 --> 00:24:26.948 but your refrigerator isn’t always running. 00:24:26.948 --> 00:24:30.323 Plus, if your refrigerator has automatic defrosting, 00:24:30.323 --> 00:24:38.002 its max power input is for the defrost heaters which require much more power than the refrigeration compressor does. 00:24:38.002 --> 00:24:44.333 Now the good news is, you can look up your refrigerator's model number and find an energy guide label for it 00:24:44.333 --> 00:24:49.113 which will tell you how much energy that model typically uses over a year. 00:24:49.113 --> 00:24:52.517 And this is true for some other appliances as well. 00:24:52.517 --> 00:25:01.078 But those figures are determined through testing which assumes an average usage pattern and an average operating environment, 00:25:01.078 --> 00:25:05.260 which is not always reflective of your particular reality. 00:25:05.260 --> 00:25:10.405 That is a complication, for sure, but it doesn’t have to feel like one. 00:25:10.405 --> 00:25:19.263 If you can get your brain in the groove of first thinking about what is actually getting accomplished, it can be very clarifying. 00:25:19.263 --> 00:25:28.109 Let’s go through another example of a device which needs a lot of power to function yet doesn’t necessarily have a huge impact on your energy bills. 00:25:28.109 --> 00:25:34.937 Electric clothes dryers here in the US often have heating elements which run at 4,500 watts. 00:25:34.937 --> 00:25:41.384 Again, a scary big number, and if you’ve ever looked at the chonky power cord your dryer is hooked up with, 00:25:41.384 --> 00:25:45.709 you might assume the dryer has a huge impact on your energy bill. 00:25:45.709 --> 00:25:49.483 Now it can, and I don’t want to minimize that, 00:25:49.483 --> 00:25:55.233 but if you’ve got your own clothes dryer at home, well think about it for a minute. 00:25:55.233 --> 00:26:01.395 Even with a big and growing family most of the time the dryer just sits there doing nothing at all. 00:26:01.395 --> 00:26:07.975 It doesn’t require any power and thus it doesn’t consume  any energy unless you’re actually using it. 00:26:07.975 --> 00:26:13.761 It’s hopefully pretty obvious that how often you  use a dryer is going to impact how much it costs to use, 00:26:13.761 --> 00:26:21.539 but what’s perhaps less obvious is that the most precise indicator of what your dryer's impact on your energy bill will be 00:26:21.539 --> 00:26:31.738 is not how often you use it or even how long it runs, it is in fact the total amount and the wetness of the laundry you’re drying with it. 00:26:31.738 --> 00:26:35.900 Drying clothes is the work you're asking it to accomplish, 00:26:35.900 --> 00:26:44.592 and the total amount of work you throw at it will determine how long the dryer actually needs to run its heating element during the dry cycle. 00:26:44.592 --> 00:26:52.209 See, the heating element doesn’t actually run constantly during a dry cycle, it turns on and off to maintain a specific temperature. 00:26:52.209 --> 00:26:57.991 And most dryers have different temperature settings, helpful for drying more delicate items. 00:26:57.991 --> 00:27:03.001 These factors mean its average power draw isn’t consistent load to load, 00:27:03.001 --> 00:27:09.326 but since the task of the dryer is simply to get water in clothing to evaporate more quickly, 00:27:09.326 --> 00:27:16.711 the more water in those clothes the more heat energy the dryer has to add to the tumbly thing before they’re dry. 00:27:16.711 --> 00:27:20.293 So again, it’s what you do that matters. 00:27:20.293 --> 00:27:23.333 Not the power draw of your devices. 00:27:23.333 --> 00:27:28.670 And that goes for nearly everything in your life, regardless of its energy source. 00:27:28.670 --> 00:27:32.299 There are some things you’re not necessarily in much control of. 00:27:32.299 --> 00:27:39.965 You can’t control the weather, for example, so how much energy is necessary to keep your home warm or cool varies from day to day. 00:27:39.965 --> 00:27:46.993 But the indoor temperature you choose to maintain will impact how much energy is required. 00:27:46.993 --> 00:27:51.489 And for the devices in your life which don’t run unless you’re using them, 00:27:51.489 --> 00:27:57.353 the work you ask them to do is the main factor to how much energy those devices need. 00:27:57.353 --> 00:28:02.385 How much food are you cooking, how many hot showers do you take, how much laundry are you doing, 00:28:02.385 --> 00:28:07.954 heck even a car uses energy based on how much you actually drive it 00:28:07.954 --> 00:28:14.376 so the answer to "how much gas am I buying?" is pegged mainly to how far you actually drive your car every day. 00:28:14.376 --> 00:28:20.762 My sincere goal with this video is to stress  the importance of an energy-first mindset, 00:28:20.762 --> 00:28:25.827 and by now I hope you see how energy matters much more than power. 00:28:25.827 --> 00:28:29.812 However, power levels do matter on some occasions. 00:28:29.812 --> 00:28:31.425 What are those? 00:28:31.425 --> 00:28:35.745 Well, there are basically three ways power can become significant. 00:28:35.745 --> 00:28:39.446 The first is the one we’ve been dancing with this whole time: 00:28:39.446 --> 00:28:41.127 Time. 00:28:41.127 --> 00:28:45.559 More powerful devices can accomplish their work more quickly. 00:28:45.559 --> 00:28:54.187 For instance, a 600 watt microwave oven will take twice as long to pop a bag of popcorn as a 1,200 watt microwave oven. 00:28:54.187 --> 00:28:58.132 They will both use a similar amount of energy to complete that task, 00:28:58.132 --> 00:29:06.941 but because the 1,200 watt microwave can pump energy into the popcorn more quickly, it will finish the job in roughly half the time. 00:29:06.941 --> 00:29:15.340 Similarly, the 3 kilowatt kettles they’ve got in the UK can boil water  in half the time that our 1,500 watt kettles over here can. 00:29:15.340 --> 00:29:22.693 But energy is energy and water is water, so the only difference between them is the speed at which they finish the job. 00:29:22.693 --> 00:29:26.197 They both use the same amount of energy to do it. 00:29:26.197 --> 00:29:33.504 Power levels become especially important to speediness when what we’re doing requires larger quantities of energy. 00:29:33.504 --> 00:29:37.391 For instance, I have an electric car. 00:29:37.391 --> 00:29:38.859 It’s a Hyundai. 00:29:38.859 --> 00:29:43.460 And it's got a 77.4 kilowatt-hour battery pack. 00:29:43.460 --> 00:29:51.649 Now, you heard "hour" after "watt" so that figure is telling us how much energy the battery pack can store. 00:29:51.649 --> 00:29:54.189 And that’s a good deal of energy. 00:29:54.280 --> 00:29:59.885 And do you see how power is going to impact how long it takes to refill that battery? 00:29:59.885 --> 00:30:04.630 My home charger can deliver 7.5 kilowatts of power. 00:30:04.630 --> 00:30:12.942 So, pop quiz, how many kilowatt-hours can my 7.5 kilowatt charger supply to the car every hour? 00:30:14.246 --> 00:30:16.253 7.5. 00:30:16.253 --> 00:30:18.009 It's not a hard one. 00:30:18.009 --> 00:30:25.686 So how many hours does it take to charge my car with my 7.5 kW charger? 00:30:25.686 --> 00:30:35.368 That’s easy, divide the 77.4 kilowatt-hours of energy the battery can store by the 7.5 kilowatts of power my charger can deliver 00:30:35.368 --> 00:30:39.385 and we get 10.32 hours of time. 00:30:39.385 --> 00:30:45.894 But, that would be a completely empty-to-full charging time which I’ve never actually needed to do. 00:30:45.894 --> 00:30:49.940 I’ve also ignored efficiency but I’ve been doing that this entire video! 00:30:49.940 --> 00:30:51.685 We’ll touch on it at the end. 00:30:51.685 --> 00:30:57.997 The reason electric car nerds are obsessed with the power numbers DC fast chargers can put out 00:30:57.997 --> 00:31:08.079 is precisely because the more powerful they are the more quickly they deliver energy, which means they shorten the time it takes to recharge a battery pack. 00:31:08.079 --> 00:31:16.450 I don’t want to get too fixated on this because there are many factors at play here between individual car models and specific charging equipment, 00:31:16.450 --> 00:31:23.906 but the reason my car can charge from 10% to 80% in 18 minutes when it’s on a sufficiently powerful charger 00:31:23.906 --> 00:31:33.437 is because its battery pack can accept an average power input of about 170 kilowatts in such a charging session. 00:31:33.437 --> 00:31:42.183 That is a bonkers amount of power which requires a significant grid hookup at a DC fast charging site, 00:31:42.183 --> 00:31:46.270 but it’s not actually a huge amount of energy. 00:31:46.270 --> 00:31:49.687 It’s only about 52 kilowatt-hours. 00:31:49.687 --> 00:31:59.728 My charger at home, since it’s power limited, needs roughly 7 hours to deliver the same amount of energy - taking the car from 10% to 80%. 00:31:59.728 --> 00:32:02.851 but it’s still the same amount of energy. 00:32:02.851 --> 00:32:10.012 More power just speeds up charging, which is important on a road trip or if you need a quick charge, 00:32:10.012 --> 00:32:15.220 but it doesn’t change how much energy  a car needs to drive a certain distance. 00:32:15.220 --> 00:32:17.707 Moving on from charging big batteries, 00:32:17.707 --> 00:32:24.864 the second way power can matter is much more significant, and that is when we have a power limit. 00:32:24.864 --> 00:32:28.112 You’ve heard me talk about electric service levels before. 00:32:28.112 --> 00:32:34.899 They’re usually described in terms of amps for  reasons having to do with how much current you can safely send through a wire 00:32:34.899 --> 00:32:38.588 but an amperage limit is also a power limit. 00:32:38.588 --> 00:32:48.704 I have 100 amp service in my home which means that the most power my home can draw before the main breaker is at risk of tripping is about 20 kilowatts. 00:32:48.704 --> 00:32:55.652 The main thing that limit means is that I can only do so much stuff at the same time. 00:32:55.652 --> 00:33:03.641 However, since there are only 24 hours in a day, a power limit is ultimately also an energy limit. 00:33:03.641 --> 00:33:09.895 With 100 amp service I can only consume 480 kilowatt-hours of energy per day. 00:33:09.895 --> 00:33:14.086 But, uh, I barely use more than that in the average month 00:33:14.086 --> 00:33:21.276 so the only practical limitation it presents to me is how many devices I can have operating at the same time. 00:33:21.276 --> 00:33:30.643 That is, unless my home actually required so much  energy that 20 kilowatts of power couldn’t fulfill its needs. 00:33:30.643 --> 00:33:34.026 I know that’s never gonna happen  for me because I live in a townhome, 00:33:34.026 --> 00:33:38.393 but if I had a grotesque McMansion which was heated by electricity, 00:33:38.393 --> 00:33:46.410 then on the coldest winter nights we face in Chicagoland 20 kilowatts might not be enough power to keep the house warm. 00:33:46.410 --> 00:33:52.419 Big houses have bigger heat losses and the colder it is outside the faster they lose heat, 00:33:52.419 --> 00:34:01.025 so if a big house is losing heat faster than 20 kilowatts of power can replace it, the house won’t stay warm. 00:34:01.025 --> 00:34:08.702 And even if 20 kilowatts was just enough to maintain a toasty  warm temp inside when it’s -15 outside, 00:34:08.702 --> 00:34:17.204 well you need some overhead for other things like lights, appliances, and whatnot - which is why those larger homes have larger electrical services. 00:34:17.204 --> 00:34:24.603 Quite note: what we just talked about is why it’s important to know your home’s actual heating and cooling needs. 00:34:24.603 --> 00:34:34.478 I made a video about HVAC system sizing and really what “size” means in the context of HVAC systems is power output. 00:34:34.478 --> 00:34:41.489 Heating a home is really just an exercise in  replacing the heat energy that leaked out of it through walls and windows, 00:34:41.489 --> 00:34:51.316 and the rate at which that energy leaves is a power figure, and therefore it tells you how much power you need to replace that heat. 00:34:51.316 --> 00:35:02.538 Through testing I determined my home only needs a sustained 5 kilowatts of power to maintain 69 degrees Fahrenheit inside when it’s -10 outside. 00:35:02.538 --> 00:35:11.543 That's why I’m confident my home won’t ever need a service upgrade - my power limit of 20 kilowatts still leaves plenty of overhead. 00:35:11.543 --> 00:35:14.615 I’ll link that video if you want to know how that testing happened 00:35:14.615 --> 00:35:22.095 but long story short, my home needs significantly less heat energy then the size of my furnace would suggest. 00:35:22.095 --> 00:35:27.912 But even within an individual dwelling, power limits sometimes get in the way. 00:35:27.912 --> 00:35:32.269 You don’t just have the service level limitation of your entire home, 00:35:32.269 --> 00:35:38.389 you can only draw so much power from each  individual electrical circuit inside your home. 00:35:38.389 --> 00:35:45.011 Here in the US this is generally gonna be either 1,800 watts or 2,400 watts depending on the circuit. 00:35:45.011 --> 00:35:51.204 And that puts a limit on what precisely you can do in each area of your home. 00:35:51.204 --> 00:35:55.521 Usually these power limits don’t matter all that much outside of the kitchen, 00:35:55.521 --> 00:36:01.985 and if your home was built in the last 50 years or so you probably have at least two circuits in the kitchen anyway. 00:36:01.985 --> 00:36:07.715 But if you’ve ever had a circuit breaker trip on you when running a portable air conditioner or heater, 00:36:07.715 --> 00:36:12.136 then you’ll have discovered firsthand the significance of a power limit. 00:36:12.136 --> 00:36:19.508 Go over it for too long and the circuit breaker will trip to keep your house from burning down due to overheating electrical wires. 00:36:19.508 --> 00:36:22.675 So, it's a good thing that there are circuit breakers! 00:36:22.675 --> 00:36:24.262 But they're a limit. 00:36:24.960 --> 00:36:34.511 To be clear, though, power limits generally only affect how much you can do at the same time and/or how quickly you can do any particular thing. 00:36:34.511 --> 00:36:42.703 They only become limitations on what you can do if you actually need more energy than a power-limited circuit can provide. 00:36:42.703 --> 00:36:50.162 And since over 24 hours even a standard 15 amp receptacle can deliver 36 kilowatt-hours of energy, 00:36:50.162 --> 00:36:54.879 that’s generally quite a rare occurrence in a typical household environment. 00:36:54.879 --> 00:37:03.634 And if you are running into that issue a lot, what you’ve got is either a design flaw in your home or you have… atypical needs.   00:37:03.634 --> 00:37:11.529 OK, so the third way power levels can matter,  and this is specific to electricity, has to do with demand charges. 00:37:11.529 --> 00:37:17.976 Electric meters used to be fully analog spinning things which could only log kilowatt-hours, 00:37:17.976 --> 00:37:27.012 and a meter reader—a human person—would swing by your house each month, actually look at it, and then write down the numbers on the display. 00:37:27.012 --> 00:37:29.982 But these days those are rare. 00:37:29.982 --> 00:37:40.484 Electric meters of today are electronic devices which can log minute-by-minute usage and report that usage to the utility through a wireless mesh communications network. 00:37:40.484 --> 00:37:50.032 And certain utilities may assess a charge based on the  maximum power draw in kilowatts of your home at a particular time. 00:37:50.032 --> 00:37:54.008 They do this because managing the electric grid is very difficult 00:37:54.008 --> 00:38:01.881 and the more power is being used at once, the harder all the generators on the grid have to work to supply that power. 00:38:01.881 --> 00:38:10.198 So fee structures sometimes exist in an attempt to get electricity customers to lower their power draw during periods of high demand. 00:38:10.198 --> 00:38:18.912 However, demand charges are entirely dependent on where you live, your utility company, and your utility company’s policies. 00:38:18.912 --> 00:38:23.151 Here in the US, demand charges are rare in residential service. 00:38:23.151 --> 00:38:26.903 You’re usually only billed by the kilowatt-hour. 00:38:26.903 --> 00:38:36.399 Many utilities allow people to opt-in to certain schemes, for instance giving folks a bill credit if they lower their power demand when the utility requests them to. 00:38:36.399 --> 00:38:41.460 But mandatory demand charges are pretty rare on the residential side. 00:38:41.460 --> 00:38:47.055 Commercial customers, on the other hand, they often are assessed a mandatory demand charge. 00:38:47.055 --> 00:38:53.885 For instance here at the office my electric bill comes with a fun $11 per kilowatt fee, 00:38:53.885 --> 00:38:59.898 determined by the highest power draw my meter saw during the midday on-peak period each month. 00:38:59.898 --> 00:39:02.018 It’s great, I love it! 00:39:02.018 --> 00:39:09.177 But - if you are subject to demand charges, you should find out how exactly they are assessed. 00:39:09.177 --> 00:39:16.113 It’s unlikely that, say, using the microwave for two minutes is going to kick off a demand charge. 00:39:16.113 --> 00:39:25.112 What’s more likely is that the utility looks at a moving window of 15, maybe 20 minutes and your demand charges, if you have them, 00:39:25.112 --> 00:39:29.365 are calculated by the average power draw during that window. 00:39:29.365 --> 00:39:33.437 But I don’t know what your situation is, I’m just encouraging you to look into that. 00:39:33.437 --> 00:39:41.739 A bunch of Europeans have mentioned that their bills include them, but in the land where kettles run at 2 or 3 thousand watts 00:39:41.739 --> 00:39:46.279 I don’t think they’re quite as granular as some folks seem to think they are. 00:39:46.279 --> 00:39:51.385 And on a closing note, it’s time to talk about efficiency. 00:39:51.385 --> 00:39:58.661 It is true that the same device will always require essentially the same amount of energy to complete a given task, 00:39:58.661 --> 00:40:05.059 but a different device may be able to do the same task while using less energy. 00:40:05.059 --> 00:40:07.746 That’s the gist of energy efficiency. 00:40:07.746 --> 00:40:10.788 We want to waste as little energy as possible, 00:40:10.788 --> 00:40:18.748 and we’ve made great strides to that end by designing devices which produce more useful work with the same amount of energy. 00:40:18.748 --> 00:40:24.751 Undoubtedly the largest leap we’ve made in efficiency comes from the humble light bulb. 00:40:24.751 --> 00:40:35.964 When I was a kid, incandescent light bulbs were still the norm, and this meant most light bulbs used 40 or 60 watts, with plenty using more than that. 00:40:35.964 --> 00:40:39.566 Each individual light bulb didn’t need all that much power, 00:40:39.566 --> 00:40:45.154 but you’d usually have at least a few burning at the same time and that quickly added up. 00:40:45.154 --> 00:40:52.134 Thinking back to my childhood kitchen, that room alone had four 60 watt light bulbs. 00:40:52.134 --> 00:41:00.427 An this meant the lights used the same amount of energy in just 20 minutes as it took to scramble my eggs. 00:41:00.427 --> 00:41:10.595 These days, though, lighting technology has advanced to the point that modern light bulbs need as little as 1/10th as much electricity to produce the same amount of light. 00:41:10.595 --> 00:41:16.122 This is fantastic and has meant lighting is no longer that significant to energy bills. 00:41:16.122 --> 00:41:24.980 And, since modern light bulbs don’t produce nearly as much waste heat, they’ve also reduced the energy required for cooling. 00:41:24.980 --> 00:41:27.985 However, in other areas 00:41:27.985 --> 00:41:30.997 there isn’t actually much more efficiency to be found. 00:41:30.997 --> 00:41:35.663 When we’re dealing with electricity, things are a little weird. 00:41:35.663 --> 00:41:39.546 Some things electricity does are perfectly efficient. 00:41:39.546 --> 00:41:48.893 This is the case for electric resistive heat - every single watt-hour a heating element consumes is released into its environment as heat. 00:41:48.893 --> 00:41:58.538 So, for example, when I use my stove, the only heat losses are the result of imperfect heat transfer between the heating elements and the cookware. 00:41:59.395 --> 00:42:04.451 But electricity generation is not 100% efficient. 00:42:04.451 --> 00:42:13.468 Only some of the thermal energy in a fuel being burned in a power plant is successfully captured by a generator and converted to electrical energy. 00:42:14.120 --> 00:42:16.791 Of course that’s not something you have control of, 00:42:16.791 --> 00:42:21.803 but it’s one reason we’re working to make electricity generation more efficient. 00:42:21.803 --> 00:42:24.508 Luckily - I don't know if you're heard this - 00:42:24.508 --> 00:42:36.868 we discovered this technology where you can build a device one time, stick it in a field, and then it collects energy from the sun or wind for free! 00:42:36.868 --> 00:42:45.058 What a concept, free! And sitting in a field sounds much easier than constantly having to pay people to search for fossil fuels, 00:42:45.058 --> 00:42:52.356 extract them, purify them, and finally move them across the country just so we can feed the result of all that hard work to a generator 00:42:52.356 --> 00:42:55.861 where the fuel gets burned up and disappears into the atmosphere, 00:42:55.861 --> 00:43:02.493 meaning we have to keep doing it forever or the generator will stop and no more electricity! 00:43:02.493 --> 00:43:09.493 I honestly don’t know why I have to explain that while yes, it does take effort to manufacture solar panels and wind turbines and batteries, 00:43:09.493 --> 00:43:18.807 you only do that one time and then you get decades of free energy from them with no input! 00:43:18.807 --> 00:43:25.789 It’s cost-effective at this point for people to buy their own oversized solar arrays and batteries and live off-grid 00:43:25.789 --> 00:43:32.234 so why the hell are you letting people convince you that renewable energy is impossibly difficult and expensive? 00:43:32.234 --> 00:43:34.547 Sorry, got a little off track there. 00:43:34.547 --> 00:43:40.828 Uh, but you should look into what we actually do with all the corn we grow in this country. 00:43:40.828 --> 00:43:45.138 40% of it isn’t food feeding you or even livestock- 00:43:45.138 --> 00:43:48.157 it’s for feeding cars! 00:43:48.157 --> 00:43:49.833 We’re doing real great! 00:43:49.833 --> 00:43:54.954 Anyway, there aren’t many efficiency gains to be had from appliances in the kitchen, 00:43:54.954 --> 00:44:03.109 but the big energy draws of your home, mainly your HVAC system and your water heater, are important areas of focus. 00:44:03.109 --> 00:44:06.242 With heat pumps, my very favorite things, 00:44:06.242 --> 00:44:17.399 we can move heat energy from one place to another and it turns out we can move more heat with a heat pump than it takes to run the heat pump! 00:44:17.399 --> 00:44:25.694 Really efficient heat pumps can turn one watt of input power into 4 or 5 watts of heat depending on conditions, 00:44:25.694 --> 00:44:27.688 and that’s no glitch in the matrix. 00:44:27.688 --> 00:44:31.719 It’s the power of moving heat energy rather than creating  it! 00:44:31.719 --> 00:44:33.728 And that’s no glitch in the matrix. 00:44:33.728 --> 00:44:40.515 Now I could talk about heat pumps all day but  I will just say my trademark phrase for those who may not be aware of it: 00:44:40.515 --> 00:44:44.513 air conditioners are heat pumps! 00:44:44.513 --> 00:44:48.114 This means if you have an air conditioner, congratulations! 00:44:48.114 --> 00:44:49.962 You've got a heat pump! 00:44:49.962 --> 00:44:55.748 And that thing works by collecting  heat energy from inside your home and pumping it outside. 00:44:55.748 --> 00:45:05.821 The only thing that turns an air conditioner into a "heat pump" is a component called the reversing valve which allows that air conditioner to run in reverse, 00:45:05.821 --> 00:45:09.857 collecting heat from outside and moving it inside. 00:45:09.857 --> 00:45:15.806 And that means the same machine can provide heating and cooling! 00:45:15.806 --> 00:45:24.651 I say this with frustration because heat pumps are  touted as new technology when in fact it’s very old technology, 00:45:24.651 --> 00:45:31.328 and the only new development is that they’ve become good enough to work effectively in cold climates like mine. 00:45:31.328 --> 00:45:36.363 Yet many HVAC professionals refuse to read the memo. 00:45:36.363 --> 00:45:43.120 Then of course there’s heat pump water heaters and  heat pump clothes dryers which are also extremely thermally moving 00:45:43.120 --> 00:45:47.470 but I’ll move on to a little thing we call vampire drain. 00:45:47.470 --> 00:45:55.633 Many electronic devices are never truly off and instead operate at very low standby power levels. 00:45:55.633 --> 00:46:03.499 Honestly, though, we’ve made great strides in this area lately  so it’s not worth too much consideration these days - 00:46:03.499 --> 00:46:14.533 but on the other hand we also have a habit of sticking gadgets like smart speakers and cameras around the house which aren’t huge power draws but they add up. 00:46:14.533 --> 00:46:20.737 I’ll ignore those, though, instead I want to talk about something which is very funny when you do the math. 00:46:20.737 --> 00:46:24.671 My microwave, as do many, has a clock. 00:46:24.671 --> 00:46:29.398 And to show the time it uses 0.7 watts. 00:46:29.398 --> 00:46:35.414 That means it consumes 16.8 watt-hours per day just being a clock. 00:46:35.414 --> 00:46:43.966 Now it uses 1,650 watts when it’s heating stuff but microwaves are famously quite fast at that. 00:46:43.966 --> 00:46:53.257 And that means depending on how I use my microwave, its clock can actually use more energy than microwaving things. 00:46:53.257 --> 00:47:02.109 I need to use the microwave at least 36.6 seconds every day to heat food just to break even with its clock. 00:47:02.109 --> 00:47:05.444 And I don’t use my microwave every day. 00:47:05.444 --> 00:47:14.262 Now, I’m pretty sure on net the clock is less significant since  when I do use the microwave I’m often using it for several minutes, 00:47:14.262 --> 00:47:23.446 but there have absolutely been days when all I did was melt some butter meaning the clock used more energy. 00:47:23.446 --> 00:47:31.930 This is not only funny, but should also make you realize microwave ovens are an extremely energy-efficient way to heat food. 00:47:31.930 --> 00:47:39.716 You only use them for a few minutes at a time because they’re literally  bombarding food with radiation and directly heating it. 00:47:39.716 --> 00:47:42.366 It’s induction cooking on steroids! 00:47:42.366 --> 00:47:46.336 Yet, people often seem ashamed of using microwave ovens. 00:47:46.336 --> 00:47:48.829 I think they’re pretty freakin’ neat. 00:47:48.829 --> 00:47:52.112 But anywho, it’s time to wrap up. 00:47:52.112 --> 00:47:56.131 Energy doesn’t have to be a mysterious thing. 00:47:56.131 --> 00:48:01.013 Yes there’s a lot of complexity to how we obtain energy sources these days, 00:48:01.013 --> 00:48:11.106 and I really hope people will step outside the familiar and embrace the possibilities of energy resources which don’t just disappear after you use them once. 00:48:11.106 --> 00:48:13.403 Like all the propane in the bottle will. 00:48:13.403 --> 00:48:16.605 Or all the gasoline you've ever put in a car's gas tank. 00:48:17.350 --> 00:48:18.724 Sorry, 00:48:18.724 --> 00:48:25.634 Uh, but see, that’s really the whole reason I’d like us to be thinking about energy a little more. 00:48:25.634 --> 00:48:32.304 When we have access to functionally limitless amounts of energy like electricity coming from a power grid, 00:48:32.304 --> 00:48:35.774 how much we use is really easy to ignore. 00:48:35.774 --> 00:48:42.192 It’s not gonna run out like the propane in this bottle will, all we have to worry about is the number on a bill. 00:48:42.192 --> 00:48:45.744 But that doesn’t mean we shouldn't be wise about it. 00:48:45.744 --> 00:48:52.495 As I hope to have helped you see, an intuitive grasp of power and energy is really helpful. 00:48:52.495 --> 00:48:55.346 It allows you to cut through all the noise out there. 00:48:55.346 --> 00:49:01.713 Like, for instance, when someone says using an  electric space heater can save you money on your heating bills. 00:49:01.713 --> 00:49:07.695 Sure, it might, but most of the time you hear that it’s just a sales pitch. 00:49:07.695 --> 00:49:15.946 You need to turn the temperature way down in the rest  of your home in order to offset the added cost of using a space heater. 00:49:15.946 --> 00:49:22.532 And every single time you run across some miracle energy-saving doodad, it’s a scam. 00:49:22.532 --> 00:49:28.271 There isn’t one weird trick to lowering your energy bills - energy is energy. 00:49:28.271 --> 00:49:35.558 Your bills are based on what you do, so if you want to lower them you have to make different choices. 00:49:35.558 --> 00:49:41.860 And when you know how power relates to energy, you have the knowledge you need to make those choices, 00:49:41.860 --> 00:49:44.862 to know what choices actually matter and why, 00:49:44.862 --> 00:49:48.703 and to know what choices are possible. 00:49:48.703 --> 00:49:51.142 This is all just a numbers game! 00:49:51.142 --> 00:49:56.003 Dust off those algebra skills  and start running some theoretical scenarios in your mind. 00:49:56.003 --> 00:50:01.063 Thinking of getting one of those portable power banks in case of a power outage? 00:50:01.063 --> 00:50:08.141 Well, you need to know how much power it can actually put  out to determine what devices it can possibly run. 00:50:08.141 --> 00:50:18.538 And assuming it meets that need, then you need to know how much energy its battery pack can store to get a sense of what all it can do for you on one charge. 00:50:18.538 --> 00:50:28.420 And finally, if you know how much energy, say, your refrigerator  actually uses in a day, you’ll know how long that battery bank can keep it going. 00:50:28.420 --> 00:50:38.889 I think it’s fair to say that that sort of understanding is going to be increasingly necessary as time goes on - or at the very least, increasingly useful. 00:50:38.889 --> 00:50:44.336 We’re coming up with all sorts of ways to both harvest and store energy these days, 00:50:44.336 --> 00:50:50.585 and the numbers you see which describe  these machines and techniques aren’t just for stats nerds. 00:50:50.585 --> 00:50:55.313 They mean real things and have real  implications to your life. 00:50:55.313 --> 00:51:00.492 I, for one, think it’s really fun to put those numbers in my personal context. 00:51:00.492 --> 00:51:03.627 And maybe it won’t be fun for you, 00:51:03.627 --> 00:51:10.556 but I think with the right mindset, you’ll discover you’re solving some mysteries before they even appear. 00:51:10.556 --> 00:51:14.927 And that, my friends, is powerful. 00:51:15.821 --> 00:51:18.522 ♫ intensely smooth jazz ♫ 00:51:20.198 --> 00:51:21.296 Time to get rid of you. 00:51:21.296 --> 00:51:22.660 Which side should I take off first? 00:51:22.660 --> 00:51:23.962 Probably this one. 00:51:27.460 --> 00:51:28.301 [poot] 00:51:28.301 --> 00:51:29.832 That was cute. 00:51:29.832 --> 00:51:31.458 Oh it smells awful. 00:51:31.458 --> 00:51:34.026 ...you’ll know how long that battery pank… 00:51:34.324 --> 00:51:35.464 pank? 00:51:36.246 --> 00:51:39.003 You'll know how long that battery pank. 00:51:39.003 --> 00:51:40.938 I just did - I said it again! 00:51:40.938 --> 00:51:44.179 Then you’ll know how long that battery pank 00:51:44.850 --> 00:51:47.008 [deep frustration] 00:51:47.008 --> 00:51:54.133 …discovered this technology where you can  build a device one time, stick it in a field somewhere… 00:51:54.133 --> 00:51:58.027 I love how there’s a loud car  right now, when I started talking about that. 00:51:58.027 --> 00:52:03.955 You will be able to determine precisely how many… well, fine! 00:52:05.930 --> 00:52:08.242 Welp, thanks for watching! 00:52:08.242 --> 00:52:12.456 I hope you found this video to be pretty powerful. 00:52:12.456 --> 00:52:13.545 ha HA! 00:52:13.620 --> 00:52:18.089 But that's not what's important. It's energy. 00:52:18.089 --> 00:52:21.040 You think about that next time.