[SOUND] Hi, my name is Tom Murphy. I'm a professor in the physics department at UC-San Diego, and today we're going to talk about energy past, present, future, with a particular emphasis on the numbers. And when it comes to numbers, I advocate a real flexibility with numbers, and rounding and just sort of a, a loose manipulation, because math is a lot easier. If you don't take numbers so seriously and some people laugh when I say that, but it's, it's really true that math is easier, division is easier, multiplication is easier if you can manipulate the numbers into something that you can do in your head, then you can quickly understand the scale. Have a problem rather something can work or not work without getting bugged on the details. So, for the instance the number pi and three are virtually the same thing. And ten over three and square root of ten, all about the same. So, you can simplify a lot of otherwise complicated math, just by being flexible and so. For instance, you can round a year to 30 million seconds. You don't need to know that it's 31.55 million to do something useful. Likewise, the US population is something like 300 million people. Forget the fact that it might be 308 one year and 310 the next, whatever. It's about 300 so, for example, the US uses something like 20 million barrels of oil per day. Now, if you have 300 million people using 20 million barrels of oil per day, that's a pretty simple division problem and you come up with 15 days per person per barrel of oil. So a person goes through a barrel of oil in about 15 days. And so, if you think about having a barrel of oil delivered to your house once every 15 days. That's somewhat staggering and puts things in perspective. But oil is only about a third of our total energy demand. So you can scale that again simple math, now it's five days to go through the equivalent energy contained in one barrel of oil. So how much energy is that? Well depends on what units you like. Whether you like, gigajoules or joules or BTUs or [UNKNOWN] all are units of energy. But, you know, comes out to six, gigajoules, 6,000,000,000 joules, 6,000,000 BTUs, 1,700 kilowatt-hours. And this is a very important point, if you divide energy by time, that's called power. And the units for power are watts. So if you take one watt is one joule per second. So if you take six gigajoules, and divide by how many seconds are in five days, you end up with about 10,000 joules per second, or 10,000 watts. That's a rate at which we go through energy. That's not watts per second. That's already a rate And that's a 24 seven constant draw of power that each American is responsible for. Now, we'll come back to putting that in perspective. And for now, I just want to point out. If you take 10,000 watts or ten Kilowatts, multiply it by 24 hours, you get 240 kilowatt hours per day. So, 240 kilowatt hours, that's now an energy cause it's a power, ten kilowatts times a time, in hours, so, that's how many energy units we use per day as Americans. So, just to put 10,000 watts into perspective. Imagine two clothes dryers running full time. They run at about 5,000 watts. Or, you could have, pick your appliance, hairdryers microwave ovens, toaster ovens, space heaters. They all run at about 1,700 watts and that's actually not a coincidence. That's because household circuits are usually rated at 15 or 20 amps and so they're kind of maxing out. What a typical outlet can handle. So they're all about 1700 watts, you need about six of those running full time to make 10,000 watts. Here's an interesting one, a human that can, who consumes about 2,000 calories per day that turns out 2,000 calories is a unit of power per day. Sorry, 2,000 calories is a unit of energy. Per day that turns into watts, and it turns out to be 100 watts. So a human runs at about 100 watts. You need 100 humans to make 10,000 watts. That's basically saying that we have 100 energy slaves working for us in America to do the things that we need to get done, so that's quite a work force. You could also have 20-watt laptops. You'd need 500 of those CFL bulbs running at 14 watts. You'd need about 700 of those. Cell phones charging. Maybe five watts to charge a cell phone so you'd need 2,000 of those to make up 10,000 watts. Or, an idle charger might be drawing about one watt, so you'd need 10,000 of those. So that, hopefully, puts 10,000 watts into perspective. That's what each of us is responsible for. Now if you know anything about your electricity bill, you might say 240 kilowatt hours a day is an awful lot. And you'd be right because if you look at a typical American household, the household uses about 35 kilowatt hours per day. Okay. That's not a whole lot compared to 240, but we do have to keep in mind that. The primary energy it takes to come up with 35 kilowatt hours of delivered energy, it requires 95 kilowatt hours of primary energy from coal [INAUDIBLE] nuclear or whatever else. So okay and natural gas it's also about 35 kilowatt hours a day usually the gas bill is in therms. So that looks a little bit different, but, you can always convert units between each other if you need to. A typical household uses about three gallons of gas a day, each gallon has about 36 kilo watt hours, contained in it in energy. So that's a little over 100 kilo watt hours in gasoline. Add all those up you've got about 235 kilo watt hours a day, and it sounds like we've reached our 240, but not so fast because a household contains more than one person. So when you work it all out it comes out to about 95 kWh/day per person spent in the home or personal vehicle. Ok, that's just 40% of the total, so where's all the rest? Well we have a huge infrastructure Supporting our lifestyle. We have industry, we have agriculture growing our food, transportation to move things all around to our stores, to each other. We have the consumer and commercial world. We have defense and government. All those things take energy. All of that happens outside of our household. And, but I think that it's important to realize that it all happens on our behalf. Our standard of living demands that we have these things happening, and so we really have to take responsibility for all that energy. And also realize that almost all of it comes from fossil fuels, which are finite in nature. If you've never looked at it, the Energy Information Agency puts out every year an annual energy review This is from 2011, and they have some nice graphs where you see pictorially how much comes from domestic fossil fuel, how much comes from imported fossil fuel. Here's nuclear and here's renewable, mostly hydroelectric and some burning wood. And then where it goes, residential, commercial, industrial, transportation. They also have some nice diagrams that sort of detail where, which things go to where. So 71% of petroleum goes to transportation, but you can ask the inverse question, say that transportation gets 93% of its energy from petroleum, or nuclear power, 100% of it goes to making electricity, but electricity is pretty diverse, 21% comes from nuclear. So a lot of great information on this kind of spider web. Diagram. So, one point I want to make that's very important to me, is that, we live in a very special time and place, here in America at this age. Prior to now, we used muscle and firewood to get our energy. And then we found fossil fuels, and an incredibly. Ramped up our energy production to a huge level, and we're near the top of the finite. We know fossil fuels are finite. We're near to the top of this curve. What happens out here, nobody knows. Anybody who tells you they know, you can't trust them, because we don't, it's not a scripted future. So, I think it's very important to keep this perspective that we're living in a very special time. All the growth that we've seen is highly dependent on this surge in fossil fuel energy. So now let's put things in perspective globally. We have we've seen in the US 10,000 watts per person, that's ten to the fourth watts. If you multiply by the number of people, 300 million people in the U.S, you get three times ten to the 12 watts. Or three [??]. So, that's the power usage of the US. The US is 20% of the world, global energy demand. So, you multiply by five to get 15 terawatts. And I'll note that US uses 20% of the global energy with less than 5% of the world population, so think about that. So 15 terawatts for the entire world. If our dream, as stated by many, is to have ten billion people, which are coming, live at US or Western standards, that implies something like 100 terrawatts of power necessary to make that happen. And so, that makes the fossil fuel look like an absolute tiny blip. And we have all this energy coming from presumably renewables to last you know, for the millennia. And it's not clear what makes us think we can do this. There's no precedent for it. So, let's just look at some of the renewables and what we can get. So, solar power reaching land comes up to a staggering 20,000 terawatts. And, even if you have all kinds of practical limitations, you could probably easily get hundreds of terawatts out of solar, if you had to. So, that looks pretty promising. But take the next step down and we look at the entire biological activity on Earth, all organisms from plankton to elephants. We're looking at 60 terawatts or there about. And how much of that can we commandeer for our own energy needs? How much of the world can we basically enslave to satisfy our energy needs. Not all of it, presumably. So five or ten terawatts might be reasonable. The wind resources, fairly similar, five or ten terawatts. And then it goes down from there, so if you look at what you need To get 100 terawatt scale. Solar is really the only renewable resource that is obvious, that can do the job. Nuclear is also interesting, but it's not technically renewable. Does mine things out of the ground, and has a finite lifetime. So, but there's more to the story than just the abundance. Because you can look at different aspects of energy resources. You can look at the abundance, the difficulty, the intermittency. Is it a demonstrated technology? Can it fuel electricity? Provide heat? Or fuel transportation, is it publicly acceptable, nuclear has some trouble there. Can you put it in your backyard and how efficient is it. And when you look at all of these things together and score them, red are bad things, and yellow, intermediate and blue are good, aspects across all those. across all those categories for the different types of alternative energies and end up all the scores. You end up with something like, one to five, whereas fossil fuels tend to be eight of ten of these points. So there is a big gap between the the benefits of fossil fuels and if it were for the fact that fossil fuels are finite in creating in creating a lot of greenhouse gases, we wouldn't be worried about this. If you want more detail in this, go to my blog, do the math, look at the alternative energy matrix, you can see lot more detail in how this is constructed. So the lesson for me is that this makes me sit up and pay attention because we're in an all hands on deck situation. We have a, an energy demand that's huge, and continuation of this under alternatives is not guaranteed. We don't know for sure that we can make this work. There are problems and issues in the way. That suggests we need to tackle this with a research effort that dwarfs everything we've ever seen. You know, Apollo-scale project, Manhattan project, Should look tiny compared to what we need to do to respond to this energy crisis of the future. So, but we don't know even if we do a lot of research, we're not going to guarantee that, that's going to work. So, we also are wise to think about ways to trim down, use less energy this way. So personally at home, I've reduced my energy footprint by about four or five times, and I still live a Western lifestyle more or less. And so you can do that, but it's not just at home. Your consumer choices matter. So, how often and where you travel, what you eat, you know, meat for instance, costs a lot of energy How can you buy things or replace things? How can you wash your clothes? All those things matter. And those are choices. So, be a friend to us all, turn off a hair dryer or two and we'll all breath a lot easier.