
Peter Thiel, Bill Gates, Khosla fund LightSail Energy in $37M Deal - DaniFong
http://blogs.wsj.com/venturecapital/2012/11/05/peter-thiel-bill-gates-khosla-get-behind-energy-storage-start-up-lightsail-in-37m-deal/
======
jacquesm
Congratulations Danielle, that's absolutely awesome. I'm still very sorry that
you didn't get funding for some of your more off the beaten path ideas but
this is as good as it gets.

If there is one person that I wish would find a connection like this it is
you, I'm sure you'll amaze us all with what you're going to achieve now that
your toolbox is filled.

This is really great news!

~~~
DaniFong
:)

Funding isn't the constraint now, it's time. But believe me there are more off
the beaten path ideas where that came from ;-)

~~~
jacquesm
> But believe me there are more off the beaten path ideas where that came from
> ;-)

I wasn't in the least worried about that ;)

Take care!

------
beagle3
Congrats to DaniFong and the rest of the LightSail team.

Large scale energy storage is an unappreciated problem. Our current grid has
to quickly scale up and down with demand, because there is no way store excess
capacity when demand is down (and therefore, no way to reuse previous excess
capacity when demand is up).

When this problem is actually solved (crossing fingers until LightSail
actually ships ...), the grid is going to undergo a serious transformation for
the first time - from a just-in-time economy to an inventory management
economy.

~~~
firemanx
I think there are many more players than you hear about, in this space. The
company I work for builds distributed, large-scale energy storage (I work on
the management and monitoring system that controls the "distributed" part),
though we're relatively unknown right now. There are several other companies
that we're aware of, all shipping products today and beginning to carve out
parts of the market with relatively little fanfare. I chalk it up to their /
our technology not being as "sexy" as something like LightSail, but
nevertheless many are beginning to deliver results right now.

Hopefully I don't sound like I'm disparaging LightSail or any of the other
possible avenues - I think we need continued investment in new methods as we
should always be pursuing improvement, and the LightSail approach sounds very
promising. I hope Thiel and Gates' involvement in this industry will bring
even more visibility to it. However, I do want to make the point that there
are people doing this today, in consumer and commercial applications, and
having real effects.

~~~
DaniFong
Good luck with your company! Management of the systems is a seriously
underappreciated and difficult problem, especially with batteries. To do it
well, you have to really know the chemistry.

I think the difference in fanfare is probably because, unless you change the
levelized _cost_ of stored energy to be less than the _cost_ of producing
power from fossil fuels in the first place, you can have a significant effect,
but you can't really change the way the mainstream grid operates. Existing
technologies can't do that.

The companies that have staked their reputation on trying to climb that
mountain are those which have attracted the likes of Vinod Khosla, Peter
Thiel, Bill Gates -- who are not in it to make a buck or megabuck, but to
change the world.

Management and monitoring is an important part of changing the world, but
whether or not it happens depends on the cost of the system. The suspense,
then, and pressure, is on us. But all players stand to play an important part
-- and make a fortune.

~~~
firemanx
Thanks for the reply, Danielle.

We are indeed a battery-based system for now, though we aren't necessarily
tied to that technology long term. We've focused on building a strength is in
flexibility and ability to distribute storage wherever its needed. It's always
exciting to see new methods of storage being developed, as I agree with you
about the economics of storage. I'm not quite convinced that batteries are an
antiquated option just yet (or aren't feasible financially or environmentally,
long term, especially as R&D continues to move there as well), but I'm just a
lowly software engineer - I'll leave it for the rest of our team to worry
about those problems :)

Congratulations on your successes thus far, and good luck for what the future
holds!

------
tptacek
Congrats, DaniFong!

You're one of those people where 10 years from now it is going to blow my mind
that I got to share an Internet message board with you.

~~~
DaniFong
Back at you tptacek!

~~~
aswanson
Doubling down on that sentiment, Dani. Proud to see you making it happen, on
something so major. I remember seeing an article in Forbes or Fortune last
summer featuring you and a few other up and comers and yelling, "I know her!"
in the bookstore. You're the truth, glad to see things happening for your
vision.

~~~
aswanson
Here we go:

[http://www.forbes.com/special-
report/2011/30-under30-12/30-u...](http://www.forbes.com/special-
report/2011/30-under30-12/30-under-30-12_energy.html)

------
foobarqux
Can you explain in detail what problem this solves and how it works to someone
with a basic background in physics?

Below is what my understanding: Current energy storage mechanisms (batteries)
are inefficient. In theory one way to store energy that would be more
efficient (why?) is to use the energy to compress air (with a conventional air
compressor?). The air is stored in a container until it is converted to
electrical energy through some inverse process (powering rotary screws?).
Unfortunately compressed air is very hot and difficult to store. Instead water
droplets can be injected into the compressed air container. These droplets
will absorb most of the energy of the compressed air. The vapour is separated
from the compressed air and stored in other containers (still as vapour?). How
is the vapour then converted back to electrical energy? Isn't the vapour just
as hot as the compressed air? Is it easier to deal with because it can be
stored in a larger volume?

~~~
DaniFong
Hopefully our website might be more enlightening... lightsail.com

I give a 3 minute TR35 award talk on the concept at the emTech conference this
year.

Starts at 5:27

[http://www.livestream.com/emtech2012/video?clipId=pla_cdd4c6...](http://www.livestream.com/emtech2012/video?clipId=pla_cdd4c6d8-00a8-4b73-8469-34b0951efe56)

~~~
Gravityloss
Very concisely laid out. I want to believe.

Stupid question: why can't you store all the energy in warm water, eliminating
the problematic (big, dangerous) pressure vessel altogether?

I envision a compressor, a heat exchanger (mist or otherwise) and an expander.
The expander and compressor are connected mechanically (they can be the same
device like in a piston engine or can be rotating machinery connected via
shaft like in a turbine).

During storing, or water warming, the expander produces less power than the
compressor so you need electrical energy to spin the system.

During energy release, or water cooling, the expander produces more power than
the compressor needs and you can use a generator to extract that.

This is pretty much a standard heat pump or refrigerator arrangement.

I assume this is not efficient because of some not at first sight obvious
quality of thermodynamics. It'd be cool to get a little bit insight into that.

By the way, your diagram's first picture with the piston is off: either the
shaft should be thicker or it should depict sealing between piston edge and
cylinder, now the volume of the pressure vessel changes very little when the
piston moves.

~~~
DaniFong
The trouble with your arrangement is that if there ∆T is low, there must be
very many cycles between mechanical and heat energy into order to store an
equivalent unit of energy. This gives very many opportunities to lose
efficiency.

There's a company out there, Isentropic Systems, that's trying this. A steep
mountain to climb.

------
tryitnow
What I find really intriguing about this is Thiel's participation - it's one
thing to get funding from Khosla, who is a cleantech cheerleader, it's really
amazing to get funding from Thiel, who is a cleanteach skeptic.

~~~
guelo
The Thiel quote made it sound like he invested in it because DoE rejected it.
I'm not sure if having such an ideologue as an investor is a good idea,
especially in the heavily regulated energy sector.

~~~
pjscott
You trust a short quote in a news article to be an accurate indication of
anything? Have you ever read an article reporting on something that you know
first-hand?

~~~
jbooth
I'm willing to trust that he said it to the reporter who then printed it.

And for the record, silly rhetoric about boots on the backs of the taxpayer is
completely out of place in an article where he should be pimping his
investment. It _does_ make it look like he invested for negative sentiment
towards the gov't rather than positive sentiment towards the company.

~~~
firemanx
To be fair - you end up having to make statements like that a lot in this
industry. Like it or not, there have been some very large, high profile
failures lately (Solyndra being one of the more prominent, but certainly not
the first or last). There is a stigma developing regarding "clean / green
tech" that we continually have to fight because of these failures, both in
terms of the general industry, but even more so if you have any connection to
public money, and often even if you don't.

------
kirpekar
Congratulations Danielle!

~~~
DaniFong
Thanks!

------
bbuffone
An old bad idea -> Many years ago i thought up an idea of creating a FEC - A
self contained unit that would convert heat from a forest fires, etc... into
energy. The units would be taken by helicopter and dropped into forest fires.
Once the fire was over move the units into a grid that could supply energy to
millions of homes.

This technology is one missing piece.

~~~
jacquesm
I'm sorry but that does not sound feasible. Large scale forest fires are
accidents and not energy generation stations. The logistics would be
prohibitive and absent any forest fires (usually considered a good thing)
you'd be babysitting a pile of rust. Also, the heat produced by a forest fire
would handily destroy your equipment.

Forest fires at scale tend to be pretty much unmanageable, people are more
than happy just to put them out without having to think about extracting
energy from them.

10 points for out of the box thinking, minus several for a lack of
feasibility. But keep at it, maybe one day you'll hit the jackpot!

------
rdl
Why did DoE reject them?

~~~
DaniFong
A knee-jerk reaction by poorly informed and motivated reviewers, which
included a fear of:

\- Hydrolock (solved by default) \- Corrosion (solved) \- Inability to
separate water and air (easy to solve and quickly solved) \- a lack of
understanding that water could provide heat to air on expansion (proven...)

We actually disproved all of their claims within 2 weeks of their decision.
The problem, however, is that you don't get a conversation when talking with
grant agencies. So most things are misunderstood and they default to funding
based on seniority.

At the time, our competitors were not taking the water based approach...

The advantage of world class investors is that, even if they disagree with
you, they think for themselves, so you can actually talk to them.

~~~
rdl
I am curious how you solve corrosion in a high pressure thermal cycling
environment for what are presumably very tiny water fog nozzles. But maybe
that is trade secret or whatever.

Naively I'd just switch out the air for N2, since it's mechanically the same
and cheap. But then, once you're using special gas, I'd look at using low and
high molecular weight (say, He and maybe some long chain which isn't going to
detonate under the working pressure?), and maybe other stuff, to see if it
would improve the product.

But maybe corrosion isn't a big problem -- there are some awesome alloys out
there. I want to get into firearm sound suppressor design and manufacture
(custom, tuned for a given weapon and load) just to justify an HPC/CFD
capability and a bunch of awesome Inconel and other alloy samples.

~~~
Mvandenbergh
The problem with low molecular weight gasses is that they lead to
embrittlement of any metal in contact with them and that they leak past your
seals something fierce. Both due to their small size.

He2 is also very expensive and H2 is very reactive which is not good either..

~~~
rdl
I want to build one of these: <http://en.wikipedia.org/wiki/Ram_accelerator>

Fortunately there's very little H2 involved (mainly I think in the later
stages), it's mainly CH4.

------
robomartin
How much air would you need to supply all the power required by all the homes
in California?

Here's my attempt to answer that question:

The first stop is to get a sense of what the realistic energy density of these
approaches might be. A quick search lands you here:

[http://en.wikipedia.org/wiki/Compressed_air_energy_storage#E...](http://en.wikipedia.org/wiki/Compressed_air_energy_storage#Energy_density_and_efficiency)

My take-away: 1 m3 of air = about 300,000 J

How much energy does a typical house in the US use per day?

[http://wiki.answers.com/Q/How_much_electricity_does_an_avera...](http://wiki.answers.com/Q/How_much_electricity_does_an_average_2-story_3-bedroom_house_use_per_day_per_month_or_per_year)

I'll use 50KWh per day

1kWh = 1,000W x 3,600s = 3,600,000J

This typical house, then, consumes 180,000,000J per day

How much air do we need to compress to provide all of the energy needs of this
one house (per day)?

180,000,000J / 300,000J = 600 m3

How many homes in California?

<http://quickfacts.census.gov/qfd/states/06/06037.html>

Let's say it's about 14,000,000 homes

How much air do we have to compress every day to service these homes:

600 m3 x 14,000,000 homes = 8,400,000,000 m3

OK, there's a number, whatever it means.

Hmmm. How much of the available air are we using?

What's the volume of air of the atmosphere?

Tough question to answer. I think the number we'd want would be that of the
Troposphere.

<http://en.wikipedia.org/wiki/Atmosphere_of_Earth>

I am going to use an over-simplification (you know, "assume a cow is a uniform
sphere of milk" type stuff) to try to get a number. Sphere within a sphere to
get the volume of the troposphere.

Average Earth diameter: 12,742km

<http://www.universetoday.com/15055/diameter-of-earth/>

Troposphere thickness: 17km

<http://en.wikipedia.org/wiki/Troposphere>

Troposphere volume: 4,341,334,943,758,290,000 m3

That means that California would use 0.00000019% of the troposphere per day if
every single home was powered using compressed air energy storage.

Put a different way: It would take nearly 1.5 million years to process all of
the air in the troposphere.

I'm not sure if the above is complete nonsense or not. The problem is far more
complex than these quickie calculations might suggest. On first inspection it
sounds like we have plenty of air to go around.

Would there be any environmental and/or air quality issues stemming from this
approach? Do we end-up with cleaner air locally because of the process?

Interesting stuff.

.

EDIT: A few more data points.

How big of a container is required to store all of this air?

The original assumption was that 1 m3 of air would compress into a 5L bottle,
or 0.005 m3.

Storage cube side length: 348m

Storage sphere diameter: 431m

How much would this much air weigh?

1 m3 of air at 20C = 1.204 kg

8,400,000,000 m3 = 10,113,600,000 kg

The question, for me, begins to be about how realistic it might be to
construct enough smaller storage vessels to capture this volume safely.

The article mentions something about 40ft standard shipping containers.
Assuming that the storage vessel has the internal dimensions of a standard
40ft container:

<http://en.wikipedia.org/wiki/Intermodal_container>

Container volume: ~ 67 m3

Containers required to store enough compressed air to supply homes in
California: ~627,000 units.

That's a lot of containers, even if the calculations are off by 100%.

~~~
DaniFong
Your calculations appear be within an order of magnitude of correct :-)

One other way to think of the number of shipping containers needed: actually
the average american home uses 30 kwh/day. At our target energy density and
efficiency we've been attempting to reach 30 kwh per m^3. 1 m^3 is
approximately the internal volume of a refrigerator. So each home gets 1
fridge worth of storage. Not so bad ;-)

~~~
robomartin
> Your calculations appear be within an order of magnitude of correct

Being within an order of magnitude is absolutely fantastic for a quick set of
calcs with unverified data pulled out of various 'net sites!

So, about 6,000psi for 1m^3 ?

I was just looking at this:

<http://www.nuvair.com/storage-storagetank.shtml>

Their NUVT6000 tanks will do it. Specs:

    
    
      Outside diameter: 9.4in
      Height: 52in
      Weight (empty): 195lbs.
      Air capacity at pressure: 510.5 ft^3
      Internal volume: 2640 in^3
    

The 30kWh you are are aiming for would require about 360 m^3 of air (perm my
prior calcs). This would require 25 of these tanks.

To double check, the internal volume of these tanks is given at 2640 in^3. 25
tanks come in at 66,000 in^3, which is just over 1 m^3.

What this highlights for me is just how large a vessel might be required to
store such a volume of air at 6,000psi due to how strong it has to be. The
external volume of these 25 tanks is approximately 1.5 m^3. Not too bad. We
are taking about a 5 x 5 tank layout; about 4 ft x 4 ft and, say, 6 ft high
with hoses, fittings and other hardware. They would weigh-in at about
5,000lbs, which might require some accommodations for a typical home garage.

Do these numbers describe what you are trying to accomplish to a reasonable
approximation?

How noisy is the process of getting the energy back out of this storage
system?

I had to look at a comparison with the energy density of current Lithium-Ion
batteries:

<http://en.wikipedia.org/wiki/Lithium-ion_battery>

    
    
      Volumetric energy density: 900 to 1,900 J/cm^3
    

We need about 108,000,000 J per house, per day.

If I assume 1,000 J/cm^3, that would require about 108,000 cm^3 in Lithium-Ion
batteries or 0.108 m^3. Yikes! On first inspection, a 1 m^3 bank of Lithium-
Ion batteries would allow you to run a house for ten days!

Not sure what that conclusion means, but Lithium-Ion, cost and other issues
aside, looks very interesting.

How about gasoline? I know, horrible, but I have to ask.

<http://en.wikipedia.org/wiki/Energy_density>

    
    
      Volumetric energy density: 34,000,000,000 J/m^3
    

Assuming 100% energy conversion we would need 0.0318 m^3 of gasoline to power
a house for an entire day. Assuming a generator is 10% efficient that number
becomes 0.3176 m^3 (317.6 liters or 83 US Gallons).

I won't do the numbers, but Liquid Propane looks very interesting.

Clearly your long term competition might very well be electrochemical battery
or graphene supercapacitor technology.

I realize you are working on a method to be used in storing excess energy for
later delivery (or smoothing out the spikes in infrastructure demands). If I
was looking for emergency power backup today I think I might have a very
serious look at Liquid Propane. I has none of the storage problems of gasoline
(namely that it degrades if not attended to) and it is very easy to use for
cooking as well as lighting, if required.

Would I want every house in my neighborhood to have LP tanks, gasoline tanks,
compressed air tanks or huge banks of Lithium-Ion batteries? Probably not.

All of these options are scary in one way or another. Imagine Hurricane Sandy,
Katrina or a good size earthquake here in CA in a scenario where every home
has one of these technologies. Could get scary very fast.

Same issues as with electric cars. Very interesting until you have an incident
involving several cars. Formula 1 teams had to make special accommodations to
use their electrical KERS systems, some of which run at 375V.

Because of this I would think that your technology (or any other high-
duration, high energy-density storage solution) might be best deployed at the
substation or generation point rather than installed in every home. Most
people are not really equipped to intelligently deal with electricity.
Sometimes it is a good idea for power to go out.

~~~
DaniFong
We get a higher energy density per m^3 of air at higher pressures. We were
aiming at 4500 psi eventually.

We aim for it not to be noisy -- any noise from high pressure air rushing out
represents wasted energy. Sonic booms from exhaust have this problem in
automobile engines, we avoid it.

Lithium ion is indeed much more dense :-)

Consider that every car has a gasoline tank, many houses have fuel oil, and we
undergird our streets with natural gas pipes, which burned down San Francisco.
I submit that air has its safety issues, but that most of these can be
avoided, and in particular, chain reactions, which threaten flammable energy
storage, can be made a non-issue.

~~~
robomartin
> Consider that every car has a gasoline tank, many houses have fuel oil

Just guessing that this could be a gating issue once you have something to
deploy. People can be irrational, even when faced with facts. I know people
that will not go into the water at the beach for fear of being attacked by a
shark. Yet, the same people don't think twice about getting into their cars in
the morning and driving on Los Angeles freeways.

Here industrial design might be the key. If the unit looks, almost literally,
like the typical freezer or refrigerator lots of people have in their garage
it might mitigate irrational first impressions.

Good luck! I'll keep an eye on developments.

------
creamyhorror
Great news, congratulations on the deal! I dare say you're a big inspiration
to a lot of young inventors out there, and we here are all awaiting big things
from you and LightSail in the near future (no pressure!).

------
ck2
Why not use excess energy to lift millions of tons of worthless rock off the
ground and then when power source fails, use the winding down via gravity to
turn generators?

Gravity is never going away and never going to run out.

~~~
technotony
I believe that the problem with this is that it's very weak, ie you need to
lift a large amount of weight to a great height to store much energy.

More details: [http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-
stor...](http://physics.ucsd.edu/do-the-math/2011/11/pump-up-the-storage/)

------
tjmc
Awesome news congratulations Dani! I've just finished 6 exams in 3rd year
mechanical engineering and it's visionary companies like Lightsail and SpaceX
that inspire all of us to keep going.

~~~
DaniFong
Thanks!

------
tylerlh
Congrats! The ideas behind this are amazing, and I'm happy to see some folks
really trying to make a difference in this market even in the wake of some
nasty history (albeit not your own).

------
tocomment
I'm confused why this technique is better than just compressing air?

~~~
Gravityloss
Air heats as it compresses. If you cool it, you lose pressure and thus energy.
So you would have to keep it hot. It's problematic because it's less dense
then and because you'd have to insulate it.

Water stores much much more heat per volume and you don't have to handle the
pressure if you keep the heat modest.

This way your air pressure vessel can be smaller and probably uninsulated.

~~~
D_Alex
As I read it, in the proposed system the heat generated during compression is
stored, and then recovered, hence the advantage over the plain old air
compression.

But I'm going to be that guy who says it will not work, and cannot work, based
on fundamental thermodynamic theory. Here goes:

1\. The best efficiency of a thermodynamic cycle is 1-TL/TH, where TL is the
temperature of heat rejection from the cycle, and TH is the temperature of
heat addition to the cycle. TL and TH are ABSOLUTE scale temperatures.

2\. In the proposed system, TH is necessarily low, no higher than the
temperature generated during compression. Efficient compressors work at low
temperatures, usually no higher than 450 K (certain INEFFICIENT compressors,
eg gas turbine compressors go as high as 700 K, the mechanical inefficiency
gets converted into heat).

3\. If <450 K assumption is correct... and if TL is the local ambient
temperature (what else?) of around 300 K the MAXIMUM efficiency of the heat
recovery cycle is 1-300/450, or about 33%. At least 67% of the heat energy
would be lost, leading to a very low overall cycle efficiency, far less than
you would get with say pumped water storage, or batteries.

Dani Fong, please comment on the above. I would be most happy if there was
something wrong in my analysis, and the new technology was a success.

~~~
DaniFong
Consider a big Carnot cycle. It's 100% reversible -- as efficient as you can
get. No losses. And it's 100% reversible no matter what temperature it
operates at.

The Carnot cycle is:

1\. Isothermal compression (T_c) 2\. Adiabatic compression (T_c -> T_h) 3\.
Isothermal expansion (T_h) 4\. Adiabatic expansion. (T_h -> T_c)

The adiabatic compression and expansion processes are just to get between the
two temperatures, T_hot and T_cold.

Suppose T_hot = T_cold.

Then there's no adiabatic section, and it's just

1\. Isothermal compression (T) 2\. Isothermal expansion (T)

The amount of energy out/energy in is T_h/T_c = 1.

This is a 100% efficient energy storage system. It is also our idealized cycle
-- a gigantic, single Carnot cycle, storing energy in heat and in low entropy,
highly compressed air.

Now, the Carnot efficiency, or the efficiency of a heat engine, is a
completely different kind of efficiency. It's the TOTAL energy out divided by
the heat in. This is

(W_out-W_in)/Q_in

In our case, the _Carnot_ efficiency is zero, even though the cycle is
reversible, and the energy storage process is completely reversible.

Interesting, no?

~~~
D_Alex
Interesting indeed, and thanks for the reply. I almost understand it,
unfortunately I just returned from our Melbourne Cup party, where lots of wine
was consumed. For now, I concede that your concept seems theoretically
possible, best of luck!

------
codex
This looks very promising. Can anyone compare and contrast with
supercapacitors, flywheels, and/or simply pumping water uphill and running it
through a generator when needed?

------
socratees
Congrats Danielle.

~~~
DaniFong
Thank you!

------
rms
:D

~~~
DaniFong
;)

~~~
sharpshoot
Been watching this develop for a while. Congrats

~~~
mindblink
Yup, me too. Great to see a big-idea tech outfit gain traction. Congrats.

------
mhartl
Congrats, Dani & co.!

~~~
DaniFong
Thanks Michael!

------
jpdoctor
Series D and they don't have a product? :eyeroll:

~~~
akiselev
Yes because only in magic software wonderland can you have millions of users
before you have any money.

Once you exit the software bubble, almost everything, especially new
technology, becomes a lot "harder" and takes a lot longer.

~~~
jpdoctor
> _Once you exit the software bubble, almost everything, especially new
> technology, becomes a lot "harder" and takes a lot longer._

I've done hardware in spades, so I'm well aware of the differences. In
hardware, Series D was either a Mezzanine round or a something-has-gone-wrong
= inside/major-dilution round

Maybe the world has changed, but having no product at D is not a sign that
things are going well on the biz side.

~~~
DaniFong
You might be overfitting the data. The initial series A, and B were
essentially a seed round. I can tell you, this was certainly an upround!

~~~
jpdoctor
Congratulations. Was it led by outsiders?

~~~
DaniFong
Lead by Peter Thiel, an outside investor.

~~~
jpdoctor
Good. Now go build some product and stop reading HN. :)

------
levlandau
Awesome! Fingers crossed for a 2014 ship date!

~~~
DaniFong
Our fingers would be crossed too, were we not using them for engineering ;-)

