1 00:00:00,040 --> 00:00:03,705 Do you know how much power the stuff in your life uses? 2 00:00:03,705 --> 00:00:05,617 Great! 3 00:00:05,617 --> 00:00:08,176 Except that doesn’t matter. 4 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, 5 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. 6 00:00:25,187 --> 00:00:29,719 This may sound like one of those overly pedantic fixations but it’s not! 7 00:00:29,719 --> 00:00:34,018 Power and energy are very different concepts. 8 00:00:34,018 --> 00:00:37,841 They are closely linked, but that’s not the whole story. 9 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. 10 00:00:46,163 --> 00:00:51,870 However, if you can wrap your head around precisely how power and energy influence each other, 11 00:00:51,870 --> 00:00:56,937 I promise a whole lotta stuff in your life gets much easier to understand. 12 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. 13 00:01:05,893 --> 00:01:08,961 This is a bottle of liquid propane. 14 00:01:08,961 --> 00:01:13,714 When sold in this kind of bottle it’s commonly used as a camping fuel. 15 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, 16 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. 17 00:01:28,125 --> 00:01:34,487 And when we ignite that mixture it burns - a chemical reaction known as combustion. 18 00:01:34,487 --> 00:01:40,550 The useful byproduct of that combustion is heat, the most basic form of energy. 19 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. 20 00:01:48,250 --> 00:01:51,466 Devices such as this camping stove. 21 00:01:51,466 --> 00:01:54,615 The stove itself is incredibly simple. 22 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. 23 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 24 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, 25 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. 26 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. 27 00:02:33,042 --> 00:02:34,857 You’ve got fire! 28 00:02:34,857 --> 00:02:37,853 And now you can cook your delicious whatever. 29 00:02:37,853 --> 00:02:44,492 Hmmm… but how much delicious whatever are you able to cook with that bottle of propane? 30 00:02:44,492 --> 00:02:49,308 That’s a good question - and its answer has to do with energy. 31 00:02:49,308 --> 00:02:53,782 Remember, we are burning the propane to release its energy. 32 00:02:53,782 --> 00:02:57,967 Since we can only burn it once and then it disappears into the atmosphere, 33 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. 34 00:03:04,853 --> 00:03:11,766 When new and full, that bottle contained one pound of liquid propane (that’s 453 grams). 35 00:03:11,766 --> 00:03:15,838 But that’s it - when it runs out it runs out. 36 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. 37 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. 38 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. 39 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. 40 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. 41 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. 42 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. 43 00:04:12,201 --> 00:04:14,496 You can even hear that difference. 44 00:04:15,278 --> 00:04:18,548 [a roaring/hissing noise grows louder and quieter] 45 00:04:18,548 --> 00:04:22,270 And just what exactly is that difference? 46 00:04:22,270 --> 00:04:24,463 It’s power. 47 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. 48 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. 49 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. 50 00:04:49,594 --> 00:04:58,782 Power, therefore, represents an instantaneous energy intensity,  which is not the same thing as energy itself. 51 00:04:58,782 --> 00:05:01,298 Why is that so important? 52 00:05:01,298 --> 00:05:06,304 Well, because energy is what actually accomplishes work. 53 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. 54 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. 55 00:05:22,131 --> 00:05:24,869 That's just a fact of physics. 56 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. 57 00:05:36,602 --> 00:05:40,120 I won't go through that calculation, but it’s on your screen now. 58 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 59 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) 60 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, 61 00:05:59,543 --> 00:06:02,781 we need to burn about 20 grams of propane. 62 00:06:02,781 --> 00:06:05,811 That’s roughly 5% of a full bottle. 63 00:06:05,811 --> 00:06:08,401 So, here’s the key question: 64 00:06:08,401 --> 00:06:12,392 does it matter what power level we have the burner is set to? 65 00:06:12,392 --> 00:06:16,761 Aside from marginal efficiency effects, no it doesn’t. 66 00:06:16,761 --> 00:06:19,430 20 grams is 20 grams. 67 00:06:19,430 --> 00:06:22,281 That’s how much propane we’re gonna use. 68 00:06:22,281 --> 00:06:26,377 How quickly we burn it doesn't matter. 69 00:06:26,377 --> 00:06:31,188 And yet, here’s where things can start to get confusing. 70 00:06:31,188 --> 00:06:38,612 When it comes to how you and I interact with our energy resources, time absolutely matters. 71 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. 72 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. 73 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. 74 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. 75 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. 76 00:07:16,734 --> 00:07:21,384 And believe it or not that right there is a power figure! 77 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. 78 00:07:29,548 --> 00:07:35,690 Remember, power, at a conceptual level, is how quickly we are using energy. 79 00:07:35,690 --> 00:07:38,764 And since the propane is our energy resource, 80 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. 81 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. 82 00:07:53,851 --> 00:07:59,342 While it may not be easy to predict  how much propane a cooking task will require, 83 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, 84 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. 85 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. 86 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: 87 00:08:28,585 --> 00:08:32,335 3.8 grams per minute for 10 minutes. 88 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. 89 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. 90 00:08:52,071 --> 00:08:54,503 So you can convert between them. 91 00:08:54,503 --> 00:08:58,879 This power level is also 4.3 horsepower. 92 00:08:58,879 --> 00:09:01,708 Or 11,000 BTU/hr. 93 00:09:01,708 --> 00:09:05,087 Or not quite one ton of refrigeration. 94 00:09:05,087 --> 00:09:08,350 Or, the power unit you’re probably most familiar with, 95 00:09:08,350 --> 00:09:11,830 3,200 watts. 96 00:09:11,830 --> 00:09:16,373 Yes, in case you weren’t aware the watt is not exclusive to electricity. 97 00:09:16,373 --> 00:09:18,454 The watt is power! 98 00:09:18,454 --> 00:09:24,907 It can mean electrical power, but it can also mean heat output or mechanical power. 99 00:09:24,907 --> 00:09:29,025 Doesn’t everybody know 1 horsepower is 746 watts? 100 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. 101 00:09:38,865 --> 00:09:43,436 First, though, what exactly is the watt? 102 00:09:43,436 --> 00:09:44,686 Simple! 103 00:09:44,686 --> 00:09:48,964 One watt is equivalent to one joule per second. 104 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, 105 00:09:57,492 --> 00:10:00,952 you just need to know it’s a specific quantity of energy. 106 00:10:00,952 --> 00:10:06,813 And how many joules of energy get used in one second is… watts. 107 00:10:06,813 --> 00:10:08,998 It’s that simple. 108 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 109 00:10:16,431 --> 00:10:20,510 this video is to help people understand how they use energy resources. 110 00:10:20,510 --> 00:10:22,613 So please just roll with it. 111 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, 112 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 113 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. 114 00:10:45,081 --> 00:10:50,588 However, joules are teeny tiny little bits of energy. 115 00:10:50,588 --> 00:10:56,285 A ten watt light bulb consumes 600 joules every minute. 116 00:10:56,285 --> 00:11:01,698 Now the good news is, just as power is power, energy is energy! 117 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. 118 00:11:09,944 --> 00:11:12,557 When we’re talking about electrical energy, 119 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, 120 00:11:17,692 --> 00:11:22,496 we usually use a unit of energy called the watt-hour. 121 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. 122 00:11:30,080 --> 00:11:33,189 The result you get is watt-hours. 123 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. 124 00:11:42,059 --> 00:11:47,051 10 watts times 3 hours equals 30 watt-hours. 125 00:11:47,051 --> 00:11:48,637 Quite simple. 126 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, 127 00:11:56,436 --> 00:12:02,164 so 30 watt-hours is equal to 108,000 joules. 128 00:12:02,164 --> 00:12:05,615 Perhaps you see why we don’t usually use joules. 129 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. 130 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. 131 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. 132 00:12:33,677 --> 00:12:36,832 It’s literally joules per second, after all, 133 00:12:36,832 --> 00:12:40,806 so in a sense the watt is a speed. 134 00:12:40,806 --> 00:12:43,199 A speed of energy. 135 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.” 136 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. 137 00:12:59,875 --> 00:13:06,214 This means the watt-hour is both a calculation that derives energy from power and time 138 00:13:06,214 --> 00:13:10,011 and the result of that calculation. 139 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. 140 00:13:15,391 --> 00:13:20,489 Not only can it seem pretty clunky to quantify energy as a calculation, 141 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. 142 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,   143 00:13:37,360 --> 00:13:42,629 we are describing a rate by saying what will get done in that time period. 144 00:13:42,629 --> 00:13:50,405 But because the watt itself is a rate (joules per second) it stands on its own. 145 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, 146 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. 147 00:14:03,827 --> 00:14:06,924 And that’s the point of the watt-hour. 148 00:14:06,924 --> 00:14:14,010 And although it can seem clunky, the watt-hour is incredibly useful to understanding energy 149 00:14:14,010 --> 00:14:19,130 because it brings the time part of this whole deal front and center. 150 00:14:19,130 --> 00:14:24,395 For instance, say you’ve got a television which uses 150 watts of power. 151 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! 152 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. 153 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. 154 00:14:45,183 --> 00:14:46,843 Watt-hours. 155 00:14:46,843 --> 00:14:48,416 Pretty simple. 156 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. 157 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, 158 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. 159 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. 160 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. 161 00:15:32,582 --> 00:15:35,207 Just makes the numbers smaller. 162 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. 163 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. 164 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, 165 00:16:01,007 --> 00:16:04,477 then you are looking at a quantity of energy. 166 00:16:04,477 --> 00:16:06,882 Not a power figure. 167 00:16:06,882 --> 00:16:13,051 And when it comes to your energy bills, energy is the only thing that matters! 168 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. 169 00:16:23,181 --> 00:16:28,786 They are only impacted by your home's total energy use in kilowatt-hours. 170 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. 171 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 - 172 00:16:47,383 --> 00:16:53,812 is this idea that electric cooking is wildly expensive compared to gas cooking. 173 00:16:53,812 --> 00:16:57,323 Now, there is some logic to why people say that: 174 00:16:57,323 --> 00:17:03,353 in general, methane gas is a less expensive source of heat than electricity is. 175 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. 176 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. 177 00:17:20,355 --> 00:17:24,579 That’s a scary big number and is indeed quite a lot of power, 178 00:17:24,579 --> 00:17:28,113 but power isn't what matters to your energy bill! 179 00:17:28,113 --> 00:17:30,113 Energy is! 180 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, 181 00:17:36,438 --> 00:17:39,031 they’re practically rounding errors. 182 00:17:39,031 --> 00:17:43,265 Think for a moment about what cooking is. 183 00:17:43,265 --> 00:17:49,304 It's simply heating food. And, yes, sometimes it makes things very hot 184 00:17:49,304 --> 00:17:53,514 But you’re only making small things very hot. 185 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. 186 00:18:02,664 --> 00:18:05,624 And remember that whole time thing? 187 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, 188 00:18:11,186 --> 00:18:14,962 likely less if you’re not an adventurous cook. 189 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. 190 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. 191 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. 192 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. 193 00:18:53,351 --> 00:18:56,171 How does that compare to my stove? 194 00:18:56,171 --> 00:19:01,663 Well, to give you a specific example of how much energy an actual cooking task needs, 195 00:19:01,663 --> 00:19:05,977 sometimes I scramble three eggs in a small pan like this. 196 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. 197 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 198 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. 199 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 200 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. 201 00:19:32,379 --> 00:19:35,635 So, how much energy does that use? 202 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. 203 00:19:48,649 --> 00:19:51,440 That is nothing! 204 00:19:51,440 --> 00:19:56,375 Literally just 1% of what my air conditioner uses in a day. 205 00:19:56,375 --> 00:19:59,348 And as far as how much that energy costs, 206 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. 207 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. 208 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 209 00:20:24,395 --> 00:20:27,556 and I overestimated by a lot! 210 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. 211 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 212 00:20:45,499 --> 00:20:52,212 was approximately 0.08 kilowatt-hours or 80 watt-hours. 213 00:20:52,212 --> 00:20:54,885 It’s a tiny amount of energy. 214 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. 215 00:21:01,983 --> 00:21:07,028 Now, granted, scrambling three eggs is not much of a cooking task. 216 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. 217 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. 218 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 219 00:21:32,633 --> 00:21:39,729 would only represent about 6.5% of the average US household’s monthly electricity consumption. 220 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. 221 00:21:46,236 --> 00:21:49,226 Or they’re peddling culture war nonsense. 222 00:21:49,226 --> 00:21:53,862 Now, to be clear, I’m not trying to sing the virtues of electric cooking. 223 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. 224 00:22:00,880 --> 00:22:06,550 Power figures in watts rarely matter, energy does. 225 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 226 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. 227 00:22:21,172 --> 00:22:24,688 I really want to encourage you to spend some time thinking about this. 228 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 229 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. 230 00:22:37,765 --> 00:22:40,980 And it’s time to drop a truth bomb. 231 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: 232 00:22:50,316 --> 00:22:53,177 it’s what you do. 233 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. 234 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. 235 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! 236 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 237 00:23:19,537 --> 00:23:24,414 but will also tell you a cumulative energy consumption in kilowatt-hours. 238 00:23:24,414 --> 00:23:27,935 And once you have that answer, now you know! 239 00:23:27,935 --> 00:23:32,364 It’s always gonna take the same amount of energy to do the same thing. 240 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, 241 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. 242 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. 243 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, 244 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. 245 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. 246 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, 247 00:24:24,396 --> 00:24:26,948 but your refrigerator isn’t always running. 248 00:24:26,948 --> 00:24:30,323 Plus, if your refrigerator has automatic defrosting, 249 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. 250 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 251 00:24:44,333 --> 00:24:49,113 which will tell you how much energy that model typically uses over a year. 252 00:24:49,113 --> 00:24:52,517 And this is true for some other appliances as well. 253 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, 254 00:25:01,078 --> 00:25:05,260 which is not always reflective of your particular reality. 255 00:25:05,260 --> 00:25:10,405 That is a complication, for sure, but it doesn’t have to feel like one. 256 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. 257 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. 258 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. 259 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, 260 00:25:41,384 --> 00:25:45,709 you might assume the dryer has a huge impact on your energy bill. 261 00:25:45,709 --> 00:25:49,483 Now it can, and I don’t want to minimize that, 262 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. 263 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. 264 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. 265 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, 266 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 267 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. 268 00:26:31,738 --> 00:26:35,900 Drying clothes is the work you're asking it to accomplish, 269 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. 270 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. 271 00:26:52,209 --> 00:26:57,991 And most dryers have different temperature settings, helpful for drying more delicate items. 272 00:26:57,991 --> 00:27:03,001 These factors mean its average power draw isn’t consistent load to load, 273 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, 274 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. 275 00:27:16,711 --> 00:27:20,293 So again, it’s what you do that matters. 276 00:27:20,293 --> 00:27:23,333 Not the power draw of your devices. 277 00:27:23,333 --> 00:27:28,670 And that goes for nearly everything in your life, regardless of its energy source. 278 00:27:28,670 --> 00:27:32,299 There are some things you’re not necessarily in much control of. 279 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. 280 00:27:39,965 --> 00:27:46,993 But the indoor temperature you choose to maintain will impact how much energy is required. 281 00:27:46,993 --> 00:27:51,489 And for the devices in your life which don’t run unless you’re using them, 282 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. 283 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, 284 00:28:02,385 --> 00:28:07,954 heck even a car uses energy based on how much you actually drive it 285 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. 286 00:28:14,376 --> 00:28:20,762 My sincere goal with this video is to stress  the importance of an energy-first mindset, 287 00:28:20,762 --> 00:28:25,827 and by now I hope you see how energy matters much more than power. 288 00:28:25,827 --> 00:28:29,812 However, power levels do matter on some occasions. 289 00:28:29,812 --> 00:28:31,425 What are those? 290 00:28:31,425 --> 00:28:35,745 Well, there are basically three ways power can become significant. 291 00:28:35,745 --> 00:28:39,446 The first is the one we’ve been dancing with this whole time: 292 00:28:39,446 --> 00:28:41,127 Time. 293 00:28:41,127 --> 00:28:45,559 More powerful devices can accomplish their work more quickly. 294 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. 295 00:28:54,187 --> 00:28:58,132 They will both use a similar amount of energy to complete that task, 296 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. 297 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. 298 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. 299 00:29:22,693 --> 00:29:26,197 They both use the same amount of energy to do it. 300 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. 301 00:29:33,504 --> 00:29:37,391 For instance, I have an electric car. 302 00:29:37,391 --> 00:29:38,859 It’s a Hyundai. 303 00:29:38,859 --> 00:29:43,460 And it's got a 77.4 kilowatt-hour battery pack. 304 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. 305 00:29:51,649 --> 00:29:54,189 And that’s a good deal of energy. 306 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? 307 00:29:59,885 --> 00:30:04,630 My home charger can deliver 7.5 kilowatts of power. 308 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? 309 00:30:14,246 --> 00:30:16,253 7.5. 310 00:30:16,253 --> 00:30:18,009 It's not a hard one. 311 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? 312 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 313 00:30:35,368 --> 00:30:39,385 and we get 10.32 hours of time. 314 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. 315 00:30:45,894 --> 00:30:49,940 I’ve also ignored efficiency but I’ve been doing that this entire video! 316 00:30:49,940 --> 00:30:51,685 We’ll touch on it at the end. 317 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 318 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. 319 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, 320 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 321 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. 322 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, 323 00:31:42,183 --> 00:31:46,270 but it’s not actually a huge amount of energy. 324 00:31:46,270 --> 00:31:49,687 It’s only about 52 kilowatt-hours. 325 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%. 326 00:31:59,728 --> 00:32:02,851 but it’s still the same amount of energy. 327 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, 328 00:32:10,012 --> 00:32:15,220 but it doesn’t change how much energy  a car needs to drive a certain distance. 329 00:32:15,220 --> 00:32:17,707 Moving on from charging big batteries, 330 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. 331 00:32:24,864 --> 00:32:28,112 You’ve heard me talk about electric service levels before. 332 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 333 00:32:34,899 --> 00:32:38,588 but an amperage limit is also a power limit. 334 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. 335 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. 336 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. 337 00:33:03,641 --> 00:33:09,895 With 100 amp service I can only consume 480 kilowatt-hours of energy per day. 338 00:33:09,895 --> 00:33:14,086 But, uh, I barely use more than that in the average month 339 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. 340 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. 341 00:33:30,643 --> 00:33:34,026 I know that’s never gonna happen  for me because I live in a townhome, 342 00:33:34,026 --> 00:33:38,393 but if I had a grotesque McMansion which was heated by electricity, 343 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. 344 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, 345 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. 346 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, 347 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. 348 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. 349 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. 350 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, 351 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. 352 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. 353 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. 354 00:35:11,543 --> 00:35:14,615 I’ll link that video if you want to know how that testing happened 355 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. 356 00:35:22,095 --> 00:35:27,912 But even within an individual dwelling, power limits sometimes get in the way. 357 00:35:27,912 --> 00:35:32,269 You don’t just have the service level limitation of your entire home, 358 00:35:32,269 --> 00:35:38,389 you can only draw so much power from each  individual electrical circuit inside your home. 359 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. 360 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. 361 00:35:51,204 --> 00:35:55,521 Usually these power limits don’t matter all that much outside of the kitchen, 362 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. 363 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, 364 00:36:07,715 --> 00:36:12,136 then you’ll have discovered firsthand the significance of a power limit. 365 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. 366 00:36:19,508 --> 00:36:22,675 So, it's a good thing that there are circuit breakers! 367 00:36:22,675 --> 00:36:24,262 But they're a limit. 368 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. 369 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. 370 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, 371 00:36:50,162 --> 00:36:54,879 that’s generally quite a rare occurrence in a typical household environment. 372 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.   373 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. 374 00:37:11,529 --> 00:37:17,976 Electric meters used to be fully analog spinning things which could only log kilowatt-hours, 375 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. 376 00:37:27,012 --> 00:37:29,982 But these days those are rare. 377 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. 378 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. 379 00:37:50,032 --> 00:37:54,008 They do this because managing the electric grid is very difficult 380 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. 381 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. 382 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. 383 00:38:18,912 --> 00:38:23,151 Here in the US, demand charges are rare in residential service. 384 00:38:23,151 --> 00:38:26,903 You’re usually only billed by the kilowatt-hour. 385 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. 386 00:38:36,399 --> 00:38:41,460 But mandatory demand charges are pretty rare on the residential side. 387 00:38:41,460 --> 00:38:47,055 Commercial customers, on the other hand, they often are assessed a mandatory demand charge. 388 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, 389 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. 390 00:38:59,898 --> 00:39:02,018 It’s great, I love it! 391 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. 392 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. 393 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, 394 00:39:25,112 --> 00:39:29,365 are calculated by the average power draw during that window. 395 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. 396 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 397 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. 398 00:39:46,279 --> 00:39:51,385 And on a closing note, it’s time to talk about efficiency. 399 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, 400 00:39:58,661 --> 00:40:05,059 but a different device may be able to do the same task while using less energy. 401 00:40:05,059 --> 00:40:07,746 That’s the gist of energy efficiency. 402 00:40:07,746 --> 00:40:10,788 We want to waste as little energy as possible, 403 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. 404 00:40:18,748 --> 00:40:24,751 Undoubtedly the largest leap we’ve made in efficiency comes from the humble light bulb. 405 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. 406 00:40:35,964 --> 00:40:39,566 Each individual light bulb didn’t need all that much power, 407 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. 408 00:40:45,154 --> 00:40:52,134 Thinking back to my childhood kitchen, that room alone had four 60 watt light bulbs. 409 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. 410 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. 411 00:41:10,595 --> 00:41:16,122 This is fantastic and has meant lighting is no longer that significant to energy bills. 412 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. 413 00:41:24,980 --> 00:41:27,985 However, in other areas 414 00:41:27,985 --> 00:41:30,997 there isn’t actually much more efficiency to be found. 415 00:41:30,997 --> 00:41:35,663 When we’re dealing with electricity, things are a little weird. 416 00:41:35,663 --> 00:41:39,546 Some things electricity does are perfectly efficient. 417 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. 418 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. 419 00:41:59,395 --> 00:42:04,451 But electricity generation is not 100% efficient. 420 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. 421 00:42:14,120 --> 00:42:16,791 Of course that’s not something you have control of, 422 00:42:16,791 --> 00:42:21,803 but it’s one reason we’re working to make electricity generation more efficient. 423 00:42:21,803 --> 00:42:24,508 Luckily - I don't know if you're heard this - 424 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! 425 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, 426 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 427 00:42:52,356 --> 00:42:55,861 where the fuel gets burned up and disappears into the atmosphere, 428 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! 429 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, 430 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! 431 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 432 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? 433 00:43:32,234 --> 00:43:34,547 Sorry, got a little off track there. 434 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. 435 00:43:40,828 --> 00:43:45,138 40% of it isn’t food feeding you or even livestock- 436 00:43:45,138 --> 00:43:48,157 it’s for feeding cars! 437 00:43:48,157 --> 00:43:49,833 We’re doing real great! 438 00:43:49,833 --> 00:43:54,954 Anyway, there aren’t many efficiency gains to be had from appliances in the kitchen, 439 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. 440 00:44:03,109 --> 00:44:06,242 With heat pumps, my very favorite things, 441 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! 442 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, 443 00:44:25,694 --> 00:44:27,688 and that’s no glitch in the matrix. 444 00:44:27,688 --> 00:44:31,719 It’s the power of moving heat energy rather than creating  it! 445 00:44:31,719 --> 00:44:33,728 And that’s no glitch in the matrix. 446 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: 447 00:44:40,515 --> 00:44:44,513 air conditioners are heat pumps! 448 00:44:44,513 --> 00:44:48,114 This means if you have an air conditioner, congratulations! 449 00:44:48,114 --> 00:44:49,962 You've got a heat pump! 450 00:44:49,962 --> 00:44:55,748 And that thing works by collecting  heat energy from inside your home and pumping it outside. 451 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, 452 00:45:05,821 --> 00:45:09,857 collecting heat from outside and moving it inside. 453 00:45:09,857 --> 00:45:15,806 And that means the same machine can provide heating and cooling! 454 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, 455 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. 456 00:45:31,328 --> 00:45:36,363 Yet many HVAC professionals refuse to read the memo. 457 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 458 00:45:43,120 --> 00:45:47,470 but I’ll move on to a little thing we call vampire drain. 459 00:45:47,470 --> 00:45:55,633 Many electronic devices are never truly off and instead operate at very low standby power levels. 460 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 - 461 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. 462 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. 463 00:46:20,737 --> 00:46:24,671 My microwave, as do many, has a clock. 464 00:46:24,671 --> 00:46:29,398 And to show the time it uses 0.7 watts. 465 00:46:29,398 --> 00:46:35,414 That means it consumes 16.8 watt-hours per day just being a clock. 466 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. 467 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. 468 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. 469 00:47:02,109 --> 00:47:05,444 And I don’t use my microwave every day. 470 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, 471 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. 472 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. 473 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. 474 00:47:39,716 --> 00:47:42,366 It’s induction cooking on steroids! 475 00:47:42,366 --> 00:47:46,336 Yet, people often seem ashamed of using microwave ovens. 476 00:47:46,336 --> 00:47:48,829 I think they’re pretty freakin’ neat. 477 00:47:48,829 --> 00:47:52,112 But anywho, it’s time to wrap up. 478 00:47:52,112 --> 00:47:56,131 Energy doesn’t have to be a mysterious thing. 479 00:47:56,131 --> 00:48:01,013 Yes there’s a lot of complexity to how we obtain energy sources these days, 480 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. 481 00:48:11,106 --> 00:48:13,403 Like all the propane in the bottle will. 482 00:48:13,403 --> 00:48:16,605 Or all the gasoline you've ever put in a car's gas tank. 483 00:48:17,350 --> 00:48:18,724 Sorry, 484 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. 485 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, 486 00:48:32,304 --> 00:48:35,774 how much we use is really easy to ignore. 487 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. 488 00:48:42,192 --> 00:48:45,744 But that doesn’t mean we shouldn't be wise about it. 489 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. 490 00:48:52,495 --> 00:48:55,346 It allows you to cut through all the noise out there. 491 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. 492 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. 493 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. 494 00:49:15,946 --> 00:49:22,532 And every single time you run across some miracle energy-saving doodad, it’s a scam. 495 00:49:22,532 --> 00:49:28,271 There isn’t one weird trick to lowering your energy bills - energy is energy. 496 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. 497 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, 498 00:49:41,860 --> 00:49:44,862 to know what choices actually matter and why, 499 00:49:44,862 --> 00:49:48,703 and to know what choices are possible. 500 00:49:48,703 --> 00:49:51,142 This is all just a numbers game! 501 00:49:51,142 --> 00:49:56,003 Dust off those algebra skills  and start running some theoretical scenarios in your mind. 502 00:49:56,003 --> 00:50:01,063 Thinking of getting one of those portable power banks in case of a power outage? 503 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. 504 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. 505 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. 506 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. 507 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, 508 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. 509 00:50:50,585 --> 00:50:55,313 They mean real things and have real  implications to your life. 510 00:50:55,313 --> 00:51:00,492 I, for one, think it’s really fun to put those numbers in my personal context. 511 00:51:00,492 --> 00:51:03,627 And maybe it won’t be fun for you, 512 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. 513 00:51:10,556 --> 00:51:14,927 And that, my friends, is powerful. 514 00:51:15,821 --> 00:51:18,522 ♫ intensely smooth jazz ♫ 515 00:51:20,198 --> 00:51:21,296 Time to get rid of you. 516 00:51:21,296 --> 00:51:22,660 Which side should I take off first? 517 00:51:22,660 --> 00:51:23,962 Probably this one. 518 00:51:27,460 --> 00:51:28,301 [poot] 519 00:51:28,301 --> 00:51:29,832 That was cute. 520 00:51:29,832 --> 00:51:31,458 Oh it smells awful. 521 00:51:31,458 --> 00:51:34,026 ...you’ll know how long that battery pank… 522 00:51:34,324 --> 00:51:35,464 pank? 523 00:51:36,246 --> 00:51:39,003 You'll know how long that battery pank. 524 00:51:39,003 --> 00:51:40,938 I just did - I said it again! 525 00:51:40,938 --> 00:51:44,179 Then you’ll know how long that battery pank 526 00:51:44,850 --> 00:51:47,008 [deep frustration] 527 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… 528 00:51:54,133 --> 00:51:58,027 I love how there’s a loud car  right now, when I started talking about that. 529 00:51:58,027 --> 00:52:03,955 You will be able to determine precisely how many… well, fine! 530 00:52:05,930 --> 00:52:08,242 Welp, thanks for watching! 531 00:52:08,242 --> 00:52:12,456 I hope you found this video to be pretty powerful. 532 00:52:12,456 --> 00:52:13,545 ha HA! 533 00:52:13,620 --> 00:52:18,089 But that's not what's important. It's energy. 534 00:52:18,089 --> 00:52:21,040 You think about that next time.