Translator: Eriko T
Reviewer: Denise RQ My name is Danielle Fong and my mission is
to provide the technology, so that people can have
abundant, sustainable energy everywhere for everyone. So my first message,
and possibly my most important one, is that we are at a critical time because we really see a ray of hope. Technology to produce power
from solar and wind has improved so much that the price of solar power
has fallen like a meteor. It is now competitive with oil,
with liquefied natural gas. It is incredibly cheap. It's not quite the cheapest in areas
where people are producing or burning coal but in many places in the world, in Europe, increasingly
across the world, it is cheap. It's only a matter of time before it is the lowest cost source
of power almost everywhere. And there's a lot of it. There's more than we could possibly need. It's well distributed
in places where people need power, there's a lot of sunlight. But there is one challenge
that must be overcome: renewable energy - solar and wind -
is intermittent. Here's a picture of the Earth and as you can see,
part of it is in shadow. There's no solar power at night. So the problem
that I'm going to speak about is the problem of how do you
store energy economically enough so that it's lower cost
than power from fossil fuels? Before I do that,
a message on how urgent the problem is: because carbon dioxide stays
in the atmosphere for a very long time, you can make a carbon dioxide budget
beyond which if you burn more, you just have increasingly difficult
climate problems you have to deal with. That carbon budget is exceeded
by the amount of carbon dioxide already accounted for in the reserves of the fossil fuel companies
and the countries that ship it out. So, actually if you go through those fossil fuels
already discovered resources. In business as usual, you burn through
the carbon budget in just 17Â years. Just to review, that means flooding:
flooding of Amsterdam, and then New York if we surpass the safe limit of two degrees centigrade
and temperature increase; you have heat waves that kill people, desertification becomes a huge problem, coral reefs are a problem
- they mostly bleach or die - less food, stronger storms,
and species going extinct. So now is a really critical time
to get in front of this. And one way that I put it is that since power plants
last a long time too, the power plants being built now
will define the biosphere for the next 5,000 years. So it's really critical
that we get this right. So how did I get involved?
What's my personal story? And I should get into this,
a word of warning, it's a little unusual, but I think there are lessons
for a lot of different people. The way i like to justify it is I have patience for people,
but I don't have patience for systems. For me personally,
when I went into high school, I felt it was just moving too slowly,
and it wasn't focused enough on teaching people real skills
to make a difference in the world. So when I left, I found
actually to my surprise, I could enter university
at a very young age, 12 years old, and I studied Physics
and Computer Science. Thank you; hold the applause. Starting early I think is something
that a lot of people can do, but the most important thing is that they use their energies and move
as quickly as possible to do something that they find truly important,
that they can make a difference in. When I chose what I needed to do
for graduate school, I knew that I wanted
to make a difference in energy, which I saw as the problem
of my generation, it had to be solved in this generation. And initially, I started working
on nuclear fusion, but again, I felt
it wasn't moving fast enough. This is a picture of the large
nuclear fusion project in France; this is a graduate school student
for scale; it's a huge project. I felt it was too big and moving
too slowly to make a difference. The first power plant
was anticipated in 2050, which, obviously, would be too late to solve the climate problems
that I cared about. So I left again, and I decided to try
to develop my own capacities and to start a company. I moved to Silicon Valley,
where strangely enough, after IÂ started posting essays,
people reached out to me including a lot of extraordinary
inventors and entrepreneurs. I worked odd jobs, and slept on couches, and eventually, I met the people
who would fund and and join my startup. Now what was that on? So I noticed the cost of solar and wind
were coming down so quickly. I'm back to this problem; I knew that there was
a missing technology, and I started focusing on
the energy storage problem. Most people think energy storage is
to store energy so you can use batteries, but the problem is to really best
fossil fuels in terms of cost, batteries are too expensive,
and they don't last long enough. Basically, you dissolve and replay
ions over, and over, and over again; and it grows these strange structures, which reduce efficiency
and reduce capacity. Everybody who has a cell phone knows that they don't last as long
after too short a time; that degradation eats up the batteries,
and you need something else. So I have the idea to store energy
and compressed air. I'm not the only one to have had this,
but the advantages are well-known. You can store energy in tanks
with compressed air very inexpensively, and the tanks last for a very long time. Why hadn't people used compressed air
to store energy all across the world? People said that it must be inefficient. And there's a simple reason for this. When you compress air, it gets hot. And as you know from hot air balloons, hot air wants to expand; it fights you. And if you compress air
to a decent enough pressure to store energy densely, it would increase
in temperature dramatically. So the pressure we use,
200 atmospheres of pressure, it would increase in temperature
more than 2,000Â degree Celsius. All of that extra heat,
unless you can capture that efficiently, that's a loss. So our focus was on increasing
the efficiency of that process. And that's what we've done,
and I'll tell you how. But basically, it's a really
big improvement in efficiency. You can see that red bar there; that's the thermal loss
that we've really shrunk down. That about doubles the efficiency
of the round-trip process. So when compressing, you want
the air to be as cool as possible, and when expanding,
you want it to be as warm as possible. We figured out how to do that
using water spray. Basically, as you compress the air
sprayed directly into the compressor, we inject water, which keeps the air cool, and then you separate
the water from the air - just in this mesh-filter thing -
you store the air in air tanks, you store the heat in hot water tanks - which you can insulate,
and it's really cheap - then you spray the warm water
back in during expansion. So that was the idea. I started a company, "LightSail Energy"
- this was in 2009 - and in 2010, we showed
that this process would actually work - we did a proof of concept - and we proved a vastly improved
thermodynamic efficiency; then we started working on the product. Here are some of the pieces
we put together, and this is what it looks like. In the process actually,
my partner pursued a method of making really low-cost air tanks
using carbon fiber, so those are some people for scale. I should point out the compressor here:
this is enough to power 500 homes. The tank there - if you have 8 of them -
powers the 500 homes for an hour. So, that's the scale.
It's a pretty large scale. Here's some of the data - I don't know if I should really
go through all of this - but basically, the process is
as you draw air in, the volume increases - this is pressure and volume - as you draw air in, it fills up
the cylinder - a valve closes - and it compresses as it goes up here, and increases the pressure
all the way up to 200Â atmospheres. Then the valve opens,
you push that air out, and the process repeats. Then, to get energy back
from the compressed air, the whole process runs in reverse, and it turns into mechanical energy
and then electrical energy, right to the socket. This is the graph that shows
the process actually working. So basically, how to describe this
is that the red line here is how efficient it was before, and how far it moves up is how efficiently we compress
without it heating up. The green is the absolute
thermodynamic ideal. The blue is the water spray,
the yellow is our efficiency following it. So the compression process occurs; as soon as the water sprays in,
the efficiency dramatically improves. So that's how the process is working. What does this mean? Remember this formula that I showed? On the left here, this is up top. This is the cost of energy
from renewable sources plus the cost of energy storage. Then on the right, that's the cost
of energy conventionally. So if I just compare this here, this is roughly the cost of energy
from conventional sources during times when it is most needed. And on the left is previous batteries, and you may have heard of Tesla Motors that released a dramatic improvement
in battery cost and that's on the right here. All of the different costs
are added up here, and you have the cost initially; the fact that you're paying
a little more for energy usage from inefficiency, and so on,
degradation over time, and that's added up. As you can see,
it's a serious improvement, but it is not quite competitive yet. So I'm looking forward
to them improving that. But right now, we have a method that we believe
will be able to produce power at a lower cost than power
from conventional sources. So basically, what that means is that people can go on to our website, ask for energy from solar power
whenever they like it, and we will go and install it; it will save them money
and provide power sustainably. We'll split the savings with them. So that's basically our story
and our progress so far. We will be releasing a product
in 2017, piloting in 2016. (Applause)
Unfortunately, this seems like a bit of baloney. Greentech media did a bit of an exposĂŠ on the firm. Unformtunately the article is behind a paywall. I was able to read it by stopping the page loader before the blocking screen appeared. Bottom line, they've done a lot of shady things, and appeared to have lied about their current accomplishments.
We looked at this in Shell in 1982, one Roger Morgan running the project. Hi, Roger, if you're there. Problem with the cycle is that if you let the hot compressed steam cool, it condenses, and it won't then be a part of the expansion cycle. Eventually, your compression chamber fills up with water, so you have to stop and pump it down. To avoid that and to keep the efficiency up, you have to lag the chamber to keep it hot, as that heat is a part of the energy that you will recover on the expansion cycle. What you won't recover is the heat in the pressure chamber walls, so you have a strength-mass problem that goes down with the volume. Roger was looking at old salt mines as the compression chamber, or perhaps exhausted gas wells. That is, it's a very large scale tech.
Note, too, her figure on costs. Solar all in is considerably more expensive than peak power, which is usually diesel standby generators and four to five times the cost of baseload. The technology still has a way to go, whatever Reddit may say.
When I see that little x next to the TED I start to get a pseudo-scientific rash. TEDx can be decent like when a good university organizes it but it can be awful too. I'm not discrediting it but I wouldn't just believe it.
As a maintainer, i love it when simplicity trumps intricate in efficiency. To clarify, it seems like the compressed air drives water across a generator which is recycled, right?
Bring on 2017! With all the work being done it is only a matter of time until a storage solar system makes economic sense for a lot of people but I really hope it is next year.
TL,DW: They are using compressed air as an energy storage. Usually there are large thermal losses because the air heats up as it is compressed and cools down while expanding. Their innovation is using water to store the heat until reexpansion thereby greatly increasing efficiency.
This is old news they closed up shop already. Batteries won out just like PV killed solar thermal.
Nice idea, I wonder why it was not build yet.
It goes into the same category as a large fly wheel. We can have a spinning fly wheel, that can store the energy in terms of motion in a large vacuum chamber.
Batteries win on practicality and speed of available power.