Steven Chu (Stanford University): Renewable Energy: Generation, Transmission, and Storage

Last Updated on June 20, 2021 by Matthew Donnelly

Hi I’m Steve Chu and I am back at Stanford University having spent a four and a quarter year sabbatical as US Secretary of Energy I’m here to talk about some renewable technologies that can actually give us clean sustainable energy and to mitigate the changes of climate change where are we today well wind has made dramatic progress in the last 30 plus years from 1980 to today we see the cause of wind plummeting and now long-term contracts are being signed today which are agreeing to sell wind electrical energy at two-and-a-half to three cents a kilowatt hour two utility companies if you compare that to new natural gas or coal if you build a new natural gas plant today and assume that natural gas over the lifetime of the plant is $4 million Btu which is historically very very low you’ll find that natural gas without wind subsidy is comparable wind is already cheaper than a new coal plant what about solar energy this is what’s called a learning curve as you go and you ship more and more solar modules out the price gets lower and lower due to a series of technological innovations the slide was made in 2008 where they showed where the price of solar modules was at that time with a prediction by 2015 it’s beginning to approach wholesale cost of electricity SMA perhaps to be 15 10 cents a kilowatt hour that projection was incorrect what we see is that we’ve already by 2015 actually reached grid parity how do I notice look again at the contracts being signed in 2008 the contracts being signed were pricing solar at 18 20 cents a kilowatt hour four years later 2014 contracts being signed in Texas pricing solar at five cents and four point eight cents a kilowatt hour grid parity amazing and so solar energy is going to become lower and lower as well as when so as I came into the parm of energy we said those are technologies they’re well on their path we will continue to find research in them because they’re going to get better but we are also seeking other disruptive technologies and by that let me tell you about first existing technology going into the 20th century that existing technology was a horse and buggy there were innovations a steam-powered car actually introduced before in the 1700s didn’t work that well never took on by the mid late 1800s the Benz motovlog using a diesel internal combustion engine it was a great car but it wasn’t disruptive because it cost too much the disruptive technology was technologically good and it met the price and it was the actual Ford Model T affordable by a large fraction of Americans that actually began to replace the horse and buggy is another example we call this a transformational technology and so the Tesla has won a wonderful gray car but it costs $100,000 it will not be a mass marketed car we need something like a Tesla that cost twenty twenty-five thousand dollars and that’s what we’re looking for and to that end we’re doing research and batteries for example the Tesla battery has about 250 watt hours per kilogram it weighs 1,200 pounds and cost $30,000 that’s a lot of money but there’s a lot of weight and we need a battery that has five times higher energy density so it weighs two or three hundred pounds and then it has ten times faster charging rate and my motto was we need a battery that could be charged faster and could last longer than the bladder that means no one really drives 400 miles in one sitting or very few people do they will stop after 200 miles if they can charge their car to go another 200 miles in five minutes that’s good enough what we have today are batteries at this energy density that weighs 1,200 pounds the next generation battery is being investigated by a number of companies are with a silicon anode they could maybe double the capacity and the third generation would combine lithium with sulfur which could again double it so then we could have a battery instead of weighing 1,200 pounds could wait a couple hundred pounds 200 pounds same weight as an internal combustion engine and transmission and it could charge we need a battery that can charge ten times faster so that would be very exciting another thing we began to think about in the Department of Energy is as you see the technology developing are you prepared for the next thing so that is for inexpensive renewable energy and instead of being passive about this we began to actively examine what happens as the technology gets better and better would it be self-limiting and let me give you an example as we transition from 10 or 15 percent renewable energy which is where we are today 10 percent to 50 percent you’ll actually need a much more flexible transmission and distribution model I should also point out when you’re 50 percent intermittent renewable energy you need backup power so the cost of renewable energy actually has to include that backup power which is standby just in case the wind doesn’t blow the Sun doesn’t shine therefore renewable energy has to get actually significantly less expensive than new natural gas it is already significantly less expensive than coal but it’s going to happen 10 and certainly 20 years from today it will happen so what else do we need we need long distance transmission we begin to need energy storage but the good news is when we have 50% intermittent energy there are days where you will have lots of surplus energy and indeed at night you can buy electricity for example in California at 1/4 the usual rate you buy electricity each cells from somewhere between a half a cent to two cents a kilowatt hour and two decades from today I am confident that we will be generating renewable energy at two cents a kilowatt hour or less so we have very inexpensive electricity we can power and replace a lot of fossil fuel but what else do we need we need and this is a challenge we need a new technology we need to be able to take water and split it into hydrogen and oxygen and then we need to capture carbon dioxide very inexpensively again we don’t have the technology today but there are a number of laboratories and a number of companies that are developing trying to develop technology that would be four times less expensive at their target price and the splitting of water into hydrogen you then have the ingredients for a real sustainable energy that is to say you take water you recycle carbon dioxide and what do you do you take the water you split it into hydrogen and oxygen you take the carbon captured carbon dioxide you have it undergo catalytic transformation to build linear hydrocarbon chains these hydrocarbon chains are the molecules we use in jet fuel and diesel fuel and in gasoline a long distance transmission line is an oil tanker we know that oil ships around the world for a couple bucks a barrel and so if we had this technology and a very inexpensive electricity the energy problem would be well on the way to getting to true sustainability as I went to Washington I confronted a embedded established economy it’s sort of like the horse and buggy whip Lobby really trying to tell Congress not to support the development of automobiles that they were dangerous and they would disrupt the American Way of life similarly there is this issue with the embedded fossil fuel companies but as a scientist in Washington it was my duty my mission to dispassionately and calmly try to inform people in as well as others in government that this is necessary it’s going to take decades we’ve got to do this but it will ultimately be the low-cost option so let me conclude of a picture one of my favorites taking Christmas Eve 1968 it was an Apollo 8 the first mission that orbited the moon and the last orbit the astronauts turned the capsule earthward and they one of the astronauts took this picture at which he called Earthrise and Bill Anders the astronaut took the pictures said we came all this way to explore the moon and the most important thing is we discovered the earth now if you look at that picture it doesn’t take too much imagination to realize the moon is not a good place to live from this vantage point Earth looks very inviting and guess what there’s nowhere else to go since 1968 we’ve discovered that the climate is changing there is very compelling evidence that a large part of it is due to humans and we have to get into a better position because really we have to take care of the earth because of us and our people and our grandchildren and there’s nowhere else to go and so that’s why I went to Washington thank you

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