
Segway Inventor Dean Kamen Thinks New Stirling Engine Will Get You Off the Grid - wglb
http://www.forbes.com/sites/christopherhelman/2014/07/02/dean-kamen-thinks-his-new-stirling-engine-could-power-the-world/?utm_campaign=techtwittersf&utm_source=twitter&utm_medium=social
======
jimmcslim
I'd say its quite inaccurate to say that Stirling engines will get you 'off
the grid'. You are exchanging one grid, electricity generation and
distribution, for another, natural gas production and distribution. Your
engine may be physically connected to a residential gas distribution network,
or practically connected to the gas industry 'grid' if you are expecting large
gas bottles to be trucked to your door every few weeks...

~~~
andrewflnr
To me the cool thing about a Stirling engine in the abstract is that it
doesn't have to run on natural gas, it can run on anything combustible. They
allude to that later on in the article, but it seems like maybe we're not
getting the super-flexible versions in the US. If they were selling that, I
would definitely consider getting one for my house (when I have a house)

~~~
gregpilling
They can be run by any heat source, including solar, geothermal, etc

~~~
sopooneo
That actually confused me. I understand how they can run _off of_ any heat
source, but then why is it touted in this article _as a_ heat source? It
mentioned that it might be a good idea for a laundry that needs a lot of hot
water. But if that's the case, don't you just need an efficient furnace to
heat the water regardless? Or is it that this thing can recapture a lot of the
energy you're already expending heating up the water by some other means?

~~~
axman6
AFAIK, a Stirling engine is basically a heat pump, it mopved heat from the
heat source to some heatsink using the expansion and ocntraction of air. If
you were to run water over the heatsink, you'd probably both heat the water
and increase the efficiency of the machine by giving a greater heat
differential and greater heat conduction rate. S you could use the heat twice
basically; one to move the engine's piston and a second time to heat water.

~~~
Dave778
stirling engines are also known as hot air engines. there are different models
and systems but i have one that already works with the temperature difference
between room temperature and my hand temperature. Awesome. There is a german
manufacturer under www.boehm-stirling.com that makes really nice stirling
motors in different forms like cars, machines and so on.

~~~
axman6
I know, my girlfriend bought me a lovely Boehm stirling engine for my birthday
a few years ago and it's fantastic =)

------
zurn
This is traditionally called "micro CHP". It has potential in places without
district heating infrastructure, otherwise DH CHP is much more efficient.

These aren't really new. Eg here is an article looking at an existing
commercial gas powered Stirling micro CHP that's quiet and designed for your
house: [http://www.f09.fh-
koeln.de/imperia/md/content/personen/somme...](http://www.f09.fh-
koeln.de/imperia/md/content/personen/sommer_klaus/forschung/rehva_micro_chp.pdf)
\- there's also a comparison to an ICE based equivalent and it has much better
electricity generation efficiency.

The total efficiency is going to depend a lot on where you use it. The heating
output is locked to the electrical output so you're always going to generate
the 5 kW of heat per each kW of electricity, so you have to stop the plant
when your hot water tank and house is heated up - or start throwing away all
the heat and just run it as a low efficiency genset.

The large pool case sounds like a fit, but from another perspective it's just
greenwashing the huge energy sink of the pool. The laundries & restaurants
case sounds better here. Or regular houses in climates where a lot of heating
is needed most of the year.

~~~
dredmorbius
If you run the number on based on an assumed 30% efficiency and retail gas
costs of $0.8 - $1.50 a therm (I _think_ that's reasonable), then you come up
with a cost per kWh of electricity within the $0.09 - $0.12 range many US
utilities charge. That is, on a cost-of-electricity basis it's a wash.

Mind: gas delivery networks likely would crumble (hopefully not literally)
under the increased demand.

Depending on system costs, this could be viable as a back-up power generation
option (blackouts, etc.), where electrical service might fail but the gas
supply would still work.

Capturing and making use of waste heat could indeed be useful. I see the
possibility of full grid independence as very slim, and not particularly
compelling (with distributed small, renewable, and intermittent generation,
the grid is a useful way to move surpluses and deficits around). Though being
somewhat immune to major grid disruptions is a possibility.

I'd also keep an eye on natural gas trends. Supplies aren't endless, though
the US EIA's estimates suggest a reference resource case of increasing
extraction through 2040 at least, the less optimistic low resource case
suggesting a peak by 2030. With fracked _oil_ extraction very likely to peak
before 2020, a transfer of fuel and energy uses onto natural gas will change
market dynamics considerably. I've got my doubts as to how long gas will
remain cheap. And suspect that its increased use in transport (EIA sees a
large role in trucking) other uses may be limited.

------
wglb
Dean Kamen is one of my heroes, actually. In particular, his effort to make
water purification machines for poverty-stricken areas is likely to have more
health impact than anything currently doable. Given that some significant
fraction of diseases are water-borne.

This is what we as engineers should be doing.

~~~
keehun
Yes and his work in FIRST. It may not be as philanthropic, but I've seen it
save lives in the US. Kids who otherwise would turn to substance
abuse/vandalism/crime, FIRST teams (at least my team) provided a safe, loving,
and an actually exciting/engaging/educational experience to kids in not-so-
nice homes and families. That man is doing something really great.

------
cjbenedikt
The approach is not entirely new. A company called Sunmachine in Germany built
a similar device producing 3KW and fed by wood pellets made from saw dust - so
even more carbon friendly. Sunmachine had to file for bankruptcy as it
couldn't find the working capital to produce the neccessary machines it had in
its order books to bridge the gap before getting paid after installation of
the units. It was aimed at the residential property market.

~~~
Lost_BiomedE
Surprising that they could not get a loan given their order backlog. Were the
margins terribly small or something?

~~~
cjbenedikt
it was during the 2008/2009 credit crunch - banks just wouldn't loan. It was
eventually auctioned off. They also had a technology to run the stirling
engine via a solar dish that tracked the course of the sun...pretty cool stuff

------
richardc12345
A similar product called WhisperGen was around a number of years ago:
[http://www.whispergen-
europe.com/productspec_en.php?fm=whisp...](http://www.whispergen-
europe.com/productspec_en.php?fm=whispergen&fp=Product%20Specs)

Stirling Engine combined heat and power appliance the size of a dishwasher.
About 10,000 Euros for 1KW of electricity output. I don't think it made it in
the marketplace.

------
uptown
Tangentially related - Anybody know anything about the progress or success of
the BloomBox from Bloom Energy? They were billed as a close-to-magical way to
produce energy when they were first announced, but I haven't heard much about
them since then.

~~~
hedgehog
Sounds like they're making progress:

[http://gigaom.com/2013/11/18/apple-solar-farm-fuel-cell-
farm...](http://gigaom.com/2013/11/18/apple-solar-farm-fuel-cell-farms-
exclusive-photos-investigative-report/)

------
Sanddancer
Maybe I'm just failing at finding the info, but does anyone know how much
natural gas is used to create that 10kw of power? As the Stirling engine is a
heat engine, my first thought is that one could potentially have a dual-mode
generator here, using solar thermal, etc, to help generate power in those
areas where it's amenable to do so.

~~~
dredmorbius
Stirling (and other thermal-cycle engines) are about 30-35% in converting heat
energy to useful work. In this case electricity. So dividing 10 kW by 30% will
give you the rough energy input. Casting that in therms/hr. (usual natural gas
billing unit in the US is therms), it's about 1.14. Residential price is on
the order of around $0.80 - $1.50/therm, so you're looking at about $25/day
for 10 kW of continuous power. Which isn't far from what you'd be paying for
electricity: $21 - 29 at $0.09 - $0.12 per kWh.

In terms of volume, 1 ft^3 is about 1025 btu, a therm is 10,000 btu, so you're
looking at 97.5, let's call it 100 ft^3 of natural gas consumption per day.

As for running a Stirling engine on solar energy, or another heat source, yes,
you could do that. Again, you need 33 kW of input power, which means a 33m^3
collecter surface -- that's 5.8m on a side, or 19 feet.

Because the Stirling's hot end is a point, you'd need tracking systems or a
working fluid to deliver heat to it from your mirrors.

Incidentally, you can answer a lot of these questions using GNU units, written
by Adrian Mariano. The great thing about it is conversion between different
units and relationships, e.g., energy per hour per unit area. I find it
invaluable in looking at energy, renewable, and related issues.

------
joncp
Does this seem like a step backward to anyone else? We want to generate
electricity with renewable sources instead of fossil fuels. Also, I'm
skeptical that a small in-home generator of any type could compete with the
efficiency of a commercial power plant, even if that plant burns natural gas.

~~~
Lagged2Death
_I 'm skeptical that a small in-home generator of any type could compete with
the efficiency of a commercial power plant, even if that plant burns natural
gas._

A small local _generator_ will certainly be behind what a big commercial
_generator_ will do, but if the waste heat is also being harnessed ("Combined
Heat and Power," or CHP), combined efficiencies of 60%-80% are possible.
Commercial electrical generation is typically around 40% efficient, so CHP
really can offer very big benefits.

Of course, there's nothing fundamentally efficient about a single family
living in a huge mansion with a 10KW energy demand and a big heated swimming
pool.

I would have guessed these things would be most attractive to hotels,
universities, airports, truck stops, apartments and condos, and other
institutional-scale places that have a significant round-the-clock demand for
electricity and hot water.

I wonder what it says about the device and the market that they're planning to
sell to well-heeled homeowners first.

~~~
regularfry
> I wonder what it says about the device and the market that they're planning
> to sell to well-heeled homeowners first.

I think the key is in where he says a unit with a fifth the output wouldn't be
a fifth the cost. If he can use the luxury end of the market to drive the
manufacturing costs down, I'm sure general retail won't be far behind.

------
chris_va
> So in 10 years will everyone have one? > “I’d say yes. Ten years from today
> the probability that you are depending on wires hanging on tree branches is
> as likely as that you’ll still be installing land lines for telephones.
> Close to zero.”

Well this seems out of touch with reality. This is how I read it: "Why
maintain 1 power plant when you can instead ship and maintain 100000 instead?"

~~~
tsotha
Remember, this is the same guy that was telling us the Segway would
revolutionize travel.

~~~
johnpowell
I remember when Kamen was going on all the morning shows saying that he was
going to change the world and transportation. Many speculated that it was a
Sterling Engine. It was the Segway.

~~~
tsotha
But the Sterling engine is 200 years old. It's hard to imagine he's going to
be able to do something spectacular with it.

------
andrewflnr
Why do they keep talking about pool heating? If I just want to heat up
something up and have natural gas on hand, I'm just going to burn the gas, not
run it through some engine and use the electricity.

~~~
kinofcain
Cogeneration is a great way to increase the efficiency of these systems. It's
not that you would buy one to heat your pool, it's that you can heat your pool
from the waste heat of the power generator. The power plant that generates
your grid-delivered electricity also generates waste heat, but it's many miles
away so that heat is discarded.

A sterling engine isn't the only type of generation that works for co-gen.
Most of these micro generation proposals involve some form of waste heat
recovery in the form of warm water.

~~~
yxhuvud
> The power plant that generates your grid-delivered electricity also
> generates waste heat, but it's many miles away so that heat is discarded.

Not necessarily. Some areas have central heating and can use both the
electricity and the waste heat.

~~~
lilsunnybee
They can't use the waste heat from the actual power generation though, just
excess heat from electrical appliance inefficiencies.

------
regularfry
An interstitial, a popover to explain the site's navigation, then an ad which
scrolls over the content? You've got to be keen to want to read this stuff.

~~~
hrjet
Didn't notice any of that. I use
[httpsb]([https://github.com/gorhill/httpswitchboard/](https://github.com/gorhill/httpswitchboard/)).
For Firefox, NoScript should do the job.

------
Crito
> _" Kamen believes that aside from mansion owners, the Beacon 10 is just
> right for businesses like laundries or restaurants that use a lot of hot
> water. With commercialization partner NRG Energy, he’s so far deployed
> roughly 20 of the machines."_

If the primary use for a potential customer is going to be heating water,
essentially doing _heat- >generator->electricity->heat->water_, how is this a
good idea? Surely people who want to heat lots of water would do better if
they cut out the middlemen and just did _heat- >water_.

Of course electricity is more versatile than hot water, but if your primary
focus is on heating lots of water and you are already committed to making heat
yourself, it seems senseless to me to not just apply the heat directly to the
water.

~~~
tsotha
They wouldn't be using electricity to heat the water. Of course you would end
up using less gas if you just heated the water directly like most of us
already do for our morning shower.

The efficiency of any heat engine depends on the gradient between the input
and output temperature. So if you have a constant supply of cold water the
Stirling engine can operate very efficiently, and the cold water becomes hot
water which you can use for other things.

Of course, like I said, this is true of _any_ heat engine. You can do the same
thing by heating a boiler and using the steam to drive a turbine, which also
generates waste heat for other things.

------
secondForty
Kamen has demonstrated a great talent for generating media coverage of his
products - think back to the incredible level of media attention around launch
of "It"... which turned out to be the segway. If he's working on a new
product, expect a similar level of media engagement.

There's a good book about development and launch of the segway "CODE NAME
GINGER: The Story Behind Ginger and Dean Kamen's Quest to Invent a New
World"[1]. It's in paperback as "Reinventing the Wheel: A Story of Genius,
Innovation, and Grand Ambition"[2]. It also has some interesting coverage of
what happened inside the company during that time.

[1] [http://www.stevekemper.net/disc.htm](http://www.stevekemper.net/disc.htm)

[2] [http://www.amazon.com/Reinventing-Wheel-Genius-Innovation-
Am...](http://www.amazon.com/Reinventing-Wheel-Genius-Innovation-
Ambition/dp/0060761385)

------
ChaoticGood
Sterling Engines are cool. Here is one being used in combination with a
Fresnel lens.
[https://www.youtube.com/watch?v=A_AFnW1bZL8](https://www.youtube.com/watch?v=A_AFnW1bZL8)

------
YZF
There's a Canadian startup that I think is doing something pretty similar:
[http://www.etalim.com/](http://www.etalim.com/)

------
driverdan
I'd love to see someone make a smaller, inexpensive stirling engine that can
be used to recapture waste energy, eg turn some AC heat into electricity.

------
orillian
As cool as this is. Even with the fact that in the US it's decided you'd hook
it up to a gas line. There is still the issue of "leasing it" to the
homeowner.

Seriously, why would anyone lease a home generator. Maybe I'm old school, but
I can't see the benefits to the homeowner if you're undercutting your savings
from installing one of these devices by paying "RENT" on the generator?

------
mkoryak
This article reminded me of a very log blog by some guy in south america who
detailed building his own hydroelectric power plant. I wanted to find it so I
could link it here but I cant. Help?

~~~
AceJohnny2
Was this it?
[http://ludens.cl/paradise/turbine/turbine.html](http://ludens.cl/paradise/turbine/turbine.html)

~~~
mkoryak
Yes! Thank you

------
mhb
No mention of the cost of the output electricity?

~~~
alex_duf
No mention of how much more efficient is it compare to any other generator
either...

------
Istof
I thought he died using a Segway, but it was the owner of the company, Jimi
Heselden [1].

[http://www.dailymail.co.uk/news/article-1315518/Segway-
tycoo...](http://www.dailymail.co.uk/news/article-1315518/Segway-tycoon-Jimi-
Heselden-dies-cliff-plunge-scooters.html)

------
EEGuy
Let's look at who's behind it, what it is, how it can be used, and where the
benefits accrue:

* Who: NRG, while not a utility, is an owner of utility-scale generation capacity. They wholesale electricity to utilities for distribution and resale. Their portfolio is largely fossil-fuel but increasingly renewables [1]. They see themselves in the "death spiral" some other generation suppliers do [3][4].

* What: Per [2], it's a combined natural-gas-in ( 50KW Th ) heat-out / grid-power-in / gas-to-electrical-power-out (Stirling engine, 10 KW max ) / grid-and-home-power-out (15KW max) / solar-power-in / battery-power-both-ways (15KW max) / inverter system, tech specs subject to change.

More per [2]:

    
    
      "A single unit can integrate natural gas, solar panels, 
      wind turbines and batteries for storage," NRG says. "The 
      device is connected to the grid, which allows the two to 
      work seamlessly together. But if the grid's power goes 
      down, the engine's energy stays up. Any excess generated 
      energy can be sent back to the grid and may be credited 
      for your benefit."
      .
      Aside from the 15 kW maximum electrical output, output 
      can be used for space heating (35 kW or 0.12 MMBTU) or
      hot water (200 gallons per hour at 70° rise). Additional 
      uses include snow melt and spa and pool heating.
      .
      The technical specifications are subject to change.
      .
      When necessary, the unit seamlessly transitions to a
      backup power system, to maintain continuous operations, 
      NRG says.
      .
      The Beacon 10 unit's dimensions are 3 ft. 8 in. long by 2 
      ft. 6 in. wide by 4 ft.high, which NRG says is slightly 
      larger than a washing machine.
      .
      The unit weighs 1,500 lbs. 
    

* How it can be used: Disrupt the utility's business by selling or leasing equipment directly to end users, and by doing energy arbitrage with the utility.

The whole business of solar integration and battery integration is optional,
and smells of "greenwashing-by-association" to me: The cheapest install of
this machine would not include a solar component nor battery, each of which
might be very expensive in addition to this machine. Who could afford all
that? Certainly not everyone.

* Where benefits accrue: See [5] for the long story, but it looks like NRG mainly. If you lease it from NRG, you may not get as much of the benefit of energy arbitrage.

* What I think of it: Regulators should insist on a "connection charge" for this and accept energy sold at wholesale prices, while selling to the user at retail prices. Disclosure: I own a solar system with net metering, but believe a "connection charge" is entirely reasonable /for those who have their own generation capability/ and thus use the grid for sale of distributed generation, but /not/ for those who don't.

=======

[1] [http://www.nrg.com/renew/renewable-
generation/](http://www.nrg.com/renew/renewable-generation/)

[2]
[http://www.energychoicematters.com/stories/20131022a.html](http://www.energychoicematters.com/stories/20131022a.html)

[3] [http://www.utilitydive.com/news/facing-decline-nrg-energy-
fo...](http://www.utilitydive.com/news/facing-decline-nrg-energy-forges-new-
business-models/234896/)

[4] www.greentechmedia.com/articles/read/NRG-Energy-Deploying-Dean-Kamens-
Solar-Smart-In-Home-Generator

[5] [http://www.theatlantic.com/technology/archive/2013/11/who-
wi...](http://www.theatlantic.com/technology/archive/2013/11/who-will-compete-
with-energy-companies-in-the-future-apple-comcast-and-you/281109/)

~~~
EdwardDiego
> The cheapest install of this machine would not include a solar component nor
> battery, each of which might be very expensive in addition to this machine.
> Who could afford all that? Certainly not everyone.

I've seen German stirling engines that use a fresnel lens focusing sunlight to
supply the heat - and the most expensive part is the sun-tracking software and
equipment.

~~~
omegant
Do you have a link?

~~~
Fundlab
[https://www.youtube.com/watch?v=HXl8DJdrsuc](https://www.youtube.com/watch?v=HXl8DJdrsuc)

------
rbanffy
I have serious objections to anything that increases reliance on fossil fuels.
Or anything that releases more carbon to the atmosphere for that matter.

There are clean ways to get you off the grid. This is not one of them. At
least not entirely.

------
menubar
Oh, it's Mr. Ultra-Hype again.

------
mattdeboard
Wait, I thought Segway inventor died after driving a Segway off a cliff. Not
trolling.

~~~
AceJohnny2
Not the inventor, the new CEO who had bought the company:
[http://en.wikipedia.org/wiki/Jimi_Heselden#Death](http://en.wikipedia.org/wiki/Jimi_Heselden#Death)

------
chadpaulson
Andrea Rossi's Energy Catalyzer, which uses LENR (Low Energy Nuclear
Reaction), is far more interesting and will actually get you off the grid.

[http://ecat.com/](http://ecat.com/)

~~~
rosser
I'll believe in ECAT when Rossi lets _anyone but himself_ test the thing, and
those tests demonstrate the things he's claiming.

