As New Hampshire contemplates its energy future, maybe we should include a bit of energy past that has never quite succeeded.
That’s the idea behind an intriguing proposal from Dean Kamen’s research firm, DEKA. It wants to power a state-owned building with a Stirling engine, a design that has shown great promise for more than a century but hasn’t been truly commercialized.
If the proposal is accepted by lawmakers and if it works, it might save the state a little money on electricity, might help DEKA turn one of Kamen’s dreams into a real business, and would go a long way toward burnishing New Hampshire’s credentials as a place where interesting technology comes to life.
So how likely is it? It’s hard to say, but since this is Granite Geek, we’ll contemplate the tech stuff before we get to the lawmaker stuff.
A Stirling engine (named after Robert Stirling, a Scottish minister who developed one of the prototypes 200 years ago) has two major differences from my car engine.
One is that it uses an external heat source to create energy and move parts around rather than an internal heat source created by a spark plug igniting a mix of gasoline and air. The other is that it is a closed-cycle engine; the internal fluids and gases stay inside, unlike the exhaust that is released by my car.
In theory, these make the Stirling engine more efficient, less polluting and more flexible than internal-combustion engines, since it can use any external heat source. In reality, issues of heat transfer through materials, sealing fluids and other engineering problems have kept it from working efficiently on a useful scale except in a few limited applications.
Enter Kamen, famous for the Segway but more importantly an inventor of medical devices, a major force in the rebirth of Manchester’s millyard tech scene and the creator of the FIRST Robotics Competition. Kamen has long been fascinated with Stirling engines, creating them in various sizes and configurations to power various devices. But they haven’t really worked out – until now, maybe.
“We have done a lot of work at DEKA to make (the Stirling engine) a more viable, a more practical technology,” said Jim Scott, a DEKA representative.
DEKA has built refrigerator-sized Stirling engines, powered by natural gas, that it says can generate 10 kilowatts of electricity and 40 kilowatts of heat. (I didn’t even know you could measure heat in kilowatts; energy units sure are confusing.)
A couple of these units have been helping power DEKA’s millyard building at 100 Commercial St. since late 2013 as part of a test, and the company has several more operating in other buildings hither and yon. It says they are living up to their promise, and now DEKA would like to put one in a state building in Concord to give the project a much higher profile.
A law (Senate Bill 489) has been proposed to allow the project to go ahead, at no cost to the state. “It’s like hooking up a generator and a water heater, that’s all,” Scott said.
Scott showed up at a legislative hearing last Tuesday to answer questions on the proposal, but as it turns out, there weren’t any questions for him. Lawmakers on the Science, Technology and Energy Committee mostly talked about whether the issue should be handled by the Legislature or handled through the Executive Council, which is usually the body that accepts gifts to the state government. They’ll discuss the issue again Thursday.
Sen. Jeb Bradley of Wolfeboro, the prime sponsor, argued that the bill had the potential to give a boost to a well-known state company, above and beyond its energy benefits. “We have nothing to lose by doing this,” he said.
Committee member Herbert Vadney, a state representative from Meredith who is a mechanical engineer, said his familiarity with Stirling engines made him less than optimistic. “I see no reason for the state to get involved in an R&D project at this point – this is a gift to somebody,” he said.
David Murotake of Nashua, another committee representative with tech background, was more supportive. “It might build New Hampshire as a skill center for Sterling engines,” he mused.
Meredith Hatfield, director of the Office of Energy and Planning, said she was interested in the project as the state ponders ways to deal with the fast-changing energy universe, where utilities and power production is being reinvented on the fly.
“We need to be looking at different ways of doing things,” she told the committee. A natural gas-fired electricity-producing engine might not be as cutting edge as fuel cells or solar panels, but adding small-scale power plants could give the state more flexibility to cope with changes coming down the pike.
Plus, she noted, DEKA’s offer is a full-scale pilot project for free. “We don’t have the budget to test it out ourselves,” she said dryly.
(David Brooks can be reached at 369-3313, dbrooks@cmonitor.com or on Twitter @GraniteGeek.)
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David, I always appreciate your articles, but would like the opportunity to share via linkedin where the best tech audience resides. Any thoughts about adding that social link?
Not sure I understand what you’re asking. You mean adding a “share this via Linkedin” button?
A good article, except for this paragraph:
“One is that it uses an external heat source to create energy and move parts around rather than an internal heat source created by a spark plug igniting a mix of gasoline and air. The other is that it is a closed-cycle engine; the internal fluids and gases stay inside, unlike the exhaust that is released by my car.”
No engine creates energy, they convert energy. A Stirling engine’s external heat source is its energy source. The same laws of thermodynamics applies as it converts heat energy to mechanical energy. Those laws require heat be transferred to the “cold” side of the engine, the external heat source (burning natural gas, in this case) means that there will be CO2 and H2O exhaust to be dumped to the environment.
A steam locomotive can be a closed cycle engine – the steam can be recovered, cooled to water, and pumped to the boiler to be turned back into high pressure steam. Its external heat source (typically a coal fired boiler) produces CO2, H2O, S2O, and larger amounts of fly ash that contains traces of all sorts of stuff, including more thorium and uranium than a nuclear power plant is allowed to release.
Yeah, “create energy” is lousy wording, isn’t it? If Kamen *could* create energy, we’d all get really excited!
40,000 watts of heat = 136485.66566 BTU
No other reporter at the Monitor gets reader comments like that (he said proudly),
A watt is a rate of energy consumption or production. To express a given amount of energy in terms of watts you generally use watt-hours. In other words you have to specify the length of time over which that wattage was used or generated, to obtain the energy, which would usually be expressed in terms of Joules.
You are mixing units! Watt is a measure of the rate of energy supply or power. BTU is a measure of energy. A Watt is a Joule per second. A BTU is 1055 Joules. That means that 1 W is ~3.4 BTU/hr. Brian is correct in the numbers, just not the units. 40,000 watts= 136,000 BTU/hr.
Hey, that’s the same output rating as our Tarm wood boiler, combined with thermal storage, and it’s more than enough to provide heat and hotwater for our 2700Sqft house no matter how cold it is outside. All I need is a sterling adapter to my flu and it’ll be a CHP!
It`s not correct this equation because on the left side you are comparing power units and in the right side you have energy units. The relation between these units is that Power is the capacity of producing energy in a time period. For example, a motor with 40,000 watts of power (about 53 horsepower, a power unit used more frequently for motors) in a second de tiempo can produce some 10,000 calories (this are energy units), that are equivalent to 39 BTU.
Unless the quote by Rep Herbert Vadney is incomplete, I do not understand his opposition – after all, this is not going to cost the state a thing. What does he mean by “this is a gift to someone”?
As a physicist who works in the energy conservation field, I too have some doubts about the potential of Stirling engines; that having been said, I am more than willing to encourage research, especially when there is no cost to the public.
His concern is that the state would be indirectly supporting one company via legislation, which leads to the question of why shouldn’t it support any other New Hampshire company that wants the state to do something which will give it publicity? I didn’t go into the argument because I’d rather talk about technology than policy.
Think they are forgetting some one has to pay for the fuel natural gas to run it, unless they are figuring that they had to pay for the energy to do the same thing anyhow? But the cost may be different for the cost of the different systems energies.
If it generates all that heat not only could it be used to help heat the building directly in the winter it could be coupled to an ammonia cycle air conditioner to help cool same
stirling engines work in reverse run one way it provides mechanical movement that is this application apply torque and it pumps heat with proper engineering (not difficult) you can have heat and electricity from nat gas in or cooling from electricity in.
When a prospective product is commercialized, isn’t that when an investment is made by someone who weighs the risks and hopes to make a profit commensurate with those risks? Why are taxpayers asked to do this? Is that really something elected officials should be doing, risking taxpayers’ money? Shouldn’t this stay in the private sector where it belongs or let the DOE get involved? Doesn’t this article seem to simply provide publicity for a private enterprise entity?
Others have touched on this conundrum but maybe there is answer. What is the eternal heat source that is used to “heat” the engine? If it’s carbon based, doesn’t that external heat source create residual waste, i.e. pollution. If so where are the advantages in using such a system.
Internal combustion leaves a lot more pollutants in the exhaust than external combustion. The internal combustion engine doesn’t even burn all the fuel, leaving some fuel vapors in the exhaust. By utilizing designs like rocket stoves to heat a Stirling engine, you end up with very few pollutants, mostly CO2 and H2O, and these heater designs are perfect when scavenging waste heat for hot water. Heat and power with fewer pollutants and greater efficiency are the promising goals of Stirling engines.
It’s an interesting idea. But the article leaves me with a lot of questions like: How does it compare to an internal combustion engine? How much of the waste heat can be utilized? Is it heating water for central heating or just for the tap? What happens to the waste heat in the summer? Do they have a website with more information?
This is just another version of CHP (combined heating and power) but using a Stirling engine. It’s hard to see any advantage to this over just burning the NG directly in an internal combustion engine hooked to a generator. Both have moving parts that will degrade over time. The major problem with CHP has been, and always will be, what to do with the heat in the summer. You can not have this unit sit idle all summer and expect any return on investment. To make the numbers come out you need a place to use all the waste heat in the summer like a swimming pool, hot tub or hot water for showers like in a hotel. If you don’t have such a place to dump all the heat generated from power generation, you’re better off purchasing power from the grid. Trust me, I have tried.
The best of both worlds is to run a Sterling engine off the exhaust and cooling heat from an internal combustion engine. If an adiabatic engine is used even more heat is available for the Sterling engine.
An internal combustion engine on natural gas running at a fixed speed can be very clean burning.
Smaller units for the home might be advantageous, especially in many parts of the country that have brutal winters. One of these in a power outage would generate electricity AND heat the house.
If the sterling powered generator is producing 10 KW of electricity that should mean the shaft power is 11.6 kW-10.4 kW depending on the type of generator was being used (induction or permanent magnet), the heat recovery is 40 kW, which argues the shaft energy recovery is 22% – 20.6%, not very good. You can do better with and internal combustion engine (diesel) and get 36%-40% shaft energy recovery (to convert to electrical power and 54%-60% heat energy recovery. ALL co-gen systems have very high system efficiency as you are utilizing most all of the fuel energy for shaft power (to convert to electricity) and the “waste” energy from the cooling and exhaust systems (through heat exchangers) to heat spaces. Conversion energy efficiency for any co-gen system should be 90+ depending on the generator type and the effectiveness of the heat exchangers. Conventional after-treatment systems will “clean-up” the exhaust to be 99.96% free of NMHC, NOx, CO and P.M. (even if it is a Diesel engine) and the exhaust will be H2O (vapor), CO2 (from any carbon based fuel), N2 and very very small amounts of NMHC, CO, NOx and P.M.
The kilowatt is a power unit; not an energy unit, and describes energy change with time. The energy change can be a) work produced, b) energy converted, etc. The metric unit is the Watt which is defined as 1 Watt = 1 Joule(of energy) per sec. or 1 W = 1J/sec. Thus a 60 W light bulb transforms 60 Joules of electrical energy to 60 Joules of light and heat (mostly heat) each second.
Energy is a Universal concept and really describes the ability of an object to exert forces. Anything with energy has the potential to exert a force. But that’s another topic.
Your electrical bill is paid in units of KW-hr; not kW since we pay for energy supplied to our homes. 1 kW-hr is 3.6 million Joules of energy.
DEKA has built refrigerator-sized Stirling engines, powered by natural gas, that it says can generate 10 kilowatts of electricity and 40 kilowatts of heat. (I didn’t even know you could measure heat in kilowatts; energy units sure are confusing.)
kW aren’t energy units. They’re units of power.
There are lots of ways to generate heat to drive one of these things. My favorite by far is Low Energy Nuclear Reaction Devices, which use the Weak Nuclear Force to do the job. But I have been following new energy paradigms for about the last 6 years and I have seen the Nickel Hydride method of used by many LENR researchers turn toward Solid State Generators.
58. Lanthanum Aluminate/Strontium Titanate Interface
The interface between lanthanum aluminate (LaAlO3) and strontium titanate (SrTiO3) is a notable materials interface because it exhibits properties not found in its constituent materials. Individually, LaAlO3 and SrTiO3 are non-magnetic insulators, yet LaAlO3/SrTiO3 interfaces exhibit electrical conductivity,[1] superconductivity,[2] ferromagnetism,[3] large negative in-plane magnetoresistance,[4] and giant persistent photoconductivity.[5] The study of how these properties emerge at the LaAlO3/SrTiO3 interface is a growing area of research in condensed matter physics.
We are not short on ways to extract energy from the environment. Another favorite is 2 dimensional approaches to Photovoltaic devices. They forecast an efficiency of 33% for these devices and they can be layered, or even printed in amazing new configurations. Twitter at @pmaher_art and see 59 21st century energy paradigm contenders.
Re: “We are not short on ways to extract energy from the environment.”
I agree. We are short on banks willing to fund these projects.
Why wall street turn down a Brillouin attempt to raise capital.
Brillouin exec Robert W. George II, said: “When we took it to Wall Street they looked at the upside potential of this kind of technology and said it is worth $Trillions. Your only trying to raise $15-20 million. It makes no sense, we can’t do that.” So ask for more. The solution is to offer Wall Street a larger piece of the pie. Ask to raise more and Wall Street will fund, since they get more. As for as Wall Street funding new energy technologies, the lesson learned is: think big or go home.
Source: Youtube video G09LRbDXGy8 at time 42:39 mm:ss
It might be baffling as to why the state wouldn’t just allow it to go forward. After all, it’s free. Besides the obvious liability concerns, any snake oil salesman could push bogus technology by using the state as a cover and offering their services or technology for free.
Good point: I hadn’t thought of that.
I get approached once every year or two by somebody who has invented a perpetual-motion machine (although they know enough not to use that term). They would love to be validated by a state building testing them.
40,000 watts of heat = 136485.66566 BTU is incorrect. The left side is power and the right side is energy. It should be
40,000 watts of heat = 136485.66566 BTU per hour
or
40,000 watt hours = 136485 BTUs
There are a number of ways to convert solar radiation into concentrated heat, negating some (potentially all) “fuel source” necessary, depending on the use of the generator. Fresnel lenses have the potential to concentrate sunlight to the point of melting softer metals. Parabolic reflectors concentrate light to very high temperatures. These are but two possibilities, and I’m not an engineer (my father was). The issue, as with all solar projects, is that they require the sun to be shining to be operational. If a large enough mass of converted solar high temperature could operate a Sterling, it would be worth trying.
It might be interesting to tie this to a Rossi E-Cat. Lots of heat in a small package.
But if you burn natural gas, instead of coal, no ash, and reduce co2.
sterlings are very good at turning heat from ANY source to power. hey would be used for cars but are slow to speed up and slow down. as constant load generators they are as clean as open air or forced air combustion can be made. when hooked up to elon musk’s teck they could run a garbage truck on hunks of wood found in the trash. running at optimum speed all the time charging batteries. imagine waste cooking oil running the garbage trucks. the roads would smell like mcdonalds. screw the saudies who needs oil
The Stirling Engine is ideally suited to duel fuel applications. With the correct modifications you could use Solar Energy through Parabolic reflectors when the sun is available and the proposed gas heat source when it is night or bad weather.
This would eliminate one of the disadvantages of present solar and wind driven generators in the when the Green energy source is not available you have a lot of expensive equipment standing idle.
I suspect the generation of electricity is secondary. If I have a hot water tank that is 70% efficient, generating 136,000 btus of hot water in an hour means that ~194,000 btu worth of natural gas went into the unit. With CHP/Sterling Engine Unit, the same 194,000 btu of natural gas into the unit. However, the output is 136,000 btus of hot water AND 34,000 btu (10kw) worth of electricity. The efficiency of the system is now 87%.
If you look in co-generation the idea is not new. The new part is doing it with a Sterling cycle engine.
Back in the 1980s I worked at Xerox in Los Angeles metro. The campus used an oil fired co-generation system. I don’t know if the engines were diesel internal combustion or turbine at the time.
Using Sterling cycle would have more advantages than just better efficiency. Sterling cycle are much easier to run flex-fuel. It could run on powdered coal, heavy oil, gasoline, natural gas or combinations.
No, Dean Kannot.
Here’s perfect application for Sterling Engines, install one in the Senate and another in the House. Then the Senate and House can create their own energy by converting all the hot air produced in those venues. Just think, using Sterling Engines the House and Senate may be produce enough energy to power their respective buildings.
Don’t know why they want to call this something new. Combine Heat Power generator is relatively common.
Using a Stirling engine to do it on a building scale is not common, however.
should work good at Yellowstone park.
“Committee member Herbert Vadney, a state representative from Meredith who is a mechanical engineer, said his familiarity with Stirling engines made him less than optimistic. “I see no reason for the state to get involved in an R&D project at this point – this is a gift to somebody,” he said.”
I agree with his assessment. I’m also a mechanical engineer and licensed professional engineer. This engine is 20% efficient and runs on natural gas. A gas turbine power plant is more efficient.
If any level of U.S. government is going to partner up with a corporation for developing new energy concepts (or perfecting old ones in this case), by volunteering to be proof of concept guinea pigs, and PERHAPS potentially benefit from such projects, the risk versus rewards aspects must first be clearly delineated.
I do not see much potential for dramatic rewards in the reducing carbon footprint department, or reducing costs department.
I suggest that governments would do much better by partnering with companies working in the revolutionary breakthrough field of power generation from LENR (low energy nuclear reactions) – especially Leonardo Corp., whose initially sold commercial 1 megawatt generator has recently, SUCCESSFULLY finished its first year of use operating at a full scale testing level in an industrial environment. The 29-page report documenting this breakthrough is due to be published any day. This LENR generator produces energy at a cost near TEN TIMES lower than fossil fuel power generators can offer.
http://www.e-catworld.com/
Italian scientist Andrea Rossi years ago invented the E-CAT cold fusion module, and has since been steadily perfecting this “cold fusion” technology, a totally non polluting LENR technology method for energy generation. His success at scaling devices up to the size of this 1MW level generator, and now having run this LENR generator for a full year means this technology is ready for prime time. This is probably the greatest scientific breakthrough in the history of humankind, and modernizing a Sterling engine is really not going to cut it for solving the problems of our sick planet.
1W-Hr = 3.412141633 BTU/hr. Inherent in this equation is the fact that you must
keep the heat ON for one Hour if you want to get your full 3.4BTUs of ENERGY in one hour.
1BTU will raise the temperature of 1Lb (1pint) of water by 1.0 degree F.
So an example of 10,000 Watt-Hrs (10KW-Hr) goes like this:
Say you have a 50 Gallon water tank (400 pints or 400 lbs)
Say you apply the 10KW of heat for one hour (10KW-Hr). How hot is your water now?
First divide the 10,000W-Hr by 400lbs = 25 W-Hr/Tank of water.
Each Watt-Hr will give you 3.412BTUs of Energy/Hour. So..
25 Watts-Hr /Tank X 3.412 BTUs /Watt-Hr = 85 Degree Water Temp Rise/Hr.
A water cooled propane powered Motor-Generator might give you the 10KW-Hr of Electricity while
WASTING 30Kw-Hr of HEAT, this wasted heat could power the Sterling engine AND a water heater.
This would make a Triple-level use of the energy in the Propane.
if one were to have a heat exchanger that would put the heat from both engines into the water tank.
Now your sort of comparing apples to apples with the proposed DEKA product. Is this an exciting breakthrough?
Maybe, maybe not. Can they compound the heat use into the Sterling AND a hot water tank? Don’t know.
Stirling engines have been the technology about to succeed all my life.
They’ve never made it for a simple, if frustrating, reason.
About the time the Stirling is proven, clever Engineers improve Internal Combustion and catch up with something not as good as a Stirling, but close enough nobody will take the risk to take the leap.
With adiabatic diesels, we have reached the theoretical limit. They aren’t widely commercial, but they will be. Fortunately, the same ceramics will help Stirling to THIS TIME obtain an efficiency lead the IC engines CANNOT match.
Of course, then someone will put a small Stirling on the exhaust gasses of an IC diesel, and we are back to quare one.
Thank your for the great article Mr. Brooks and I wish Mr. Kamen much success with his efforts at bringing stirling engines to the distributed generation space. Bringing such a prestigious presence to the field can only benefit all, the spotlight is welcome. (enough with the rooftop solar panels !) I’ve been in the power generation industry for over 25 years and have a start up company providing hybrid concentrating solar equipment that incorporates, among other technologies stirling engines into our distributed energy strategies. While there may be many pro’s and cons to this particular technology, there is tremendous opportunity in this rapidly growing segment of the energy marketplace and if we are ever going to make meaningful progress in moving from the centralized, fossil fuel consuming power structure, it has to start with public awareness and you’ve provided just such an article. Great read and comments.
hi how can ibuy 25 kw stirling engine?
This is the most up-to-date information I’ve found on the Beacon 10 from DEKA. I am eager to know the status of manufacture (as a consumer, not a producer). Are they running into quality problems while ramping up production? Or has it stalled? We have grid-tied residential solar, but haven’t invested in battery storage yet, and even a 2.5KW DEKA would be a great back up to weeks of rainy winter weather.
I would like to know more about this. Is there a Sterling engine that can be used there is a grid down. I live in South Florida. We get the Hurricanes from time to time. Gasoline, LP Gas, and other types of fuel isn’t easy to get. The one thing we do have is Wood! Broke trees, broken homes, but lots of wood. From what I know about the Sterling engine can run on wood. I know that running on wood would not be easy to control the speed, and the 60Hz. But making low voltage that can be changed to 120V AC by inverters to use for things. Just like to know if there is some place I can get a sterling engine that can really do something. I have found some toy ones but nothing that can really do any work. If you can just tell me where I can get the engine the rest I may be able do the rest.
Hello David…like others above, I also would love to get updates about the DEKA engine. Specifically if they still plan to make a residential one as well.
I appreciate any and all information you have!
Thanks for the write-up and pictures.
Subscribe to my newsletter and you’ll be sure to get the news. bit.ly/monitornewsletters … I noted a couple months ago that the state will be launching an RFP and hopes to install the engine in a state building somewhere this summer.
Have watched many smart individuals miss the point, in the simplest of questions a simple answer is lurking, if the thought is deemed too difficult, so must be the reality.
Clearly the burning of any resource to achieve any power as a by- product is an negative application, Firstly, many desert areas are consistent in weather patterns & don’t experience winters, to say, but they do have extremely hot daylight hours, & frosty cold nights due to the open landscape & broad clear skylines.
Considering the potential use of Solar energy to super heat collected sands & enabling power creation via old methods, steam engines.
Stirling engines could use the same concept in areas of low water collections, or of limited reserves tangible for use as a resource to be wasted on industry.
Mining data would indicate sites perfect for facilities in Geo-thermal Stirling power creation. The heat found underground can be used effectively & constantly with
little environmental damage.
Usage of non-profitable previous exploration sites that could sustain the requirements needed for a long term power facility capable of 24/7 clean energy using one of the earths by-products opposed to the many of it’s precious resources.
Instead of “needing” to burn a resource use something that’s burning.
So many years of development, so many simple applications, too many closed minds, heard of thermal springs.
Someone give me a job or some cash to get in on this, the science crew are stuck for ideas, or stalling….?
Who Or Where would a Beacon 10 be purchased? The co-generation feature would make it a hot (pardon pun) in Alberta, Canada where there is massive amounts of Natural Gas as well as Siberia like winters in the Central Part of the Province, this is a more reliable power solution that the Current Socialist Regeim that is busy lining the pockets of there buddies. What would the cost be and and shipping to Canada. If there is any demonstration projects, would be very interested and a working unit keeping my house warm and lit would attract the attention of many farm and ranch operations around here as they can have upto 11 days without power in winter. I am in Hanna, Alberta, Canada, P.O. box 2075