Why can't I "just buy" a stirling engine?

[RobinRobin]

I'm literally dreaming of stirling engines since I've been 14 years old - because they're just that cool.
Now I'm a bit older (okay, much much older ;)) and own a house with a fireplace.

I'd love to add a Stirling engine to this fireplace with, lets say 500W or 1KW electrical output which feeds into the solar batteries / grid.
But why isn't there a solution available? Am I just too stupid to google? Could you please help me out? :)

Regards
Robin'Robin

[Administrator]

ebay....search....Stirling engine

[RobinRobin]

That's where I've already checked, but there are only model engines there, no bigger engines?

[Goofy]

Perhaps you can try one of these :
https://coolenergy.com/wp-content/uploa ... 190930.pdf

BR

[tenbitcomb]

I think the OP's point is that there are effectively no consumer-grade Stirling engines commercially available for producing usable electrical power. Every single Stirling engine that can be bought off the shelf right now are curiosities that aren't designed to do something useful like charge a cell phone or a battery. The company for that flyer you linked to probably isn't mass producing engines or prepared to sell them to individuals.

This is a question I'm trying to answer myself. My only guess is that it's perceived that the market just isn't there. Unlike a solar panel, a Stirling engine requires manual start and, though less noisy than an internal combustion engine, still produces noise. Burning things externally to fuel an engine also just isn't in vogue for a variety of reasons.

That said, my gut tells me there actually is practical value to Stirling engines and other heat engines. Maybe most people don't have a need for them, but heat engines are woefully underinvestigated, and there definitely are many examples of them performing really well. I could see off-gridders and folks interested in peparedness being interested in a mass produced Stirling engine. I like the idea of a heat engine being a redundant power source, and in particular I'm interested in taking waste paper and converting it to electrical power. Heat engines are basically the ultimate "flex fuel" engines because you can fuel them with just about anything that burns.

After all, look at what's going on with the fuel crisis in Europe. If things get a lot worse, I imagine the person who finally figures out how to sell a practical Stirling engine could make a pretty penny.

[Tom Booth]

My impression lately is that companies building Stirling engines are already making millions.

It's just that there are much more lucrative markets than some guy (like me) wanting to live off the land and power his off grid cabin.

Take for example:


https://youtu.be/iEnV40GzvD4


These buoys sport 1kw "backup" Stirling engines. Millitary, Aerospace, Offshore Oil and Gas rigs, pipelines etc.

[staska]

Answer is simple - it is much more expensive per watt compared to ic. I know, i tried it. Still have idea to make them in kit form at useful power level. But it is still in a 1000-2000 usd area for mere few hundred watts.

[Tom Booth]

Answer is simple - it is much more expensive per watt compared to ic. I know, i tried it. Still have idea to make them in kit form at useful power level. But it is still in a 1000-2000 usd area for mere few hundred watts.

I don't know, I could be wrong, and it might not work at all, but from what little information I've been able to dig up on the subject, it seems probable, a Ringbom conversion could be quite powerful and very inexpensive.

[staska]

Answer is simple - it is much more expensive per watt compared to ic. I know, i tried it. Still have idea to make them in kit form at useful power level. But it is still in a 1000-2000 usd area for mere few hundred watts.

I don't know, I could be wrong, and it might not work at all, but from what little information I've been able to dig up on the subject, it seems probable, a Ringbom conversion could be quite powerful and very inexpensive.

Ringbom - yes, powerful and inexpensive and unstable. Or working in narrow set of power / temperature area with decent efficiency..

[Tom Booth]

When it comes to Stirling/Heat engines in general, Ringbom type engines are arguably the least understood and most "woefully underinvestigated" of them all.

It is difficult to find even a toy Ringbom.

I think the biggest inherent flaw in Stirling engines is the rather persistent idea that they absolutely require a chiller, or "sink" for removing the heat after it is used to power the engine. An Alpha configuration with a dedicated cold "power piston" (sic) being a case in point. Seems rather like trying to get around by dragging a dead horse.

[Tom Booth]

Another problem is, almost any engine is designed and built around some particular engine/machine combination, as well as the availability of a particular fuel.

There is not just one IC engine, there are thousands all associated with some particular machine and fuel type.

The fact that Stirling engines are "universal" as far as potential fuel source only complicates the issue.

A Stirling generator to run on firewood would be very different from one designed to run on hot waste water or biogas or hydrogen or solar etc.

Which is the idea of my "custom" Stirling engine shop.

The market for any kind of generic stand alone engine is pretty limited.

Even if someone asked for an engine to run on their wood stove...

What kind of stove? Where is the feed door/shoot? Does it take logs or pellets, is it top fed, etc. etc etc.

[CincyD]

Im new here and have no expertise but since we are all interested -why cant we just ...make it ourselves? Create a plan (copy NASAs), find the materials/manufacturer and ...just figure it all out?

[Tom Booth]

I was going to say that after so many years thinking about how to design a Stirling engine, part of the problem is there are potentially dozens of possible heat sources including the various liquid fuels, direct solar, indirect solar, industrial waste heat, geothermal, air source heat pump, a candle, cup of coffee or even cold.

Each different heat source would necessitate a certain modification or an entirely different type engine and different types of heat engine would be more suited for one application or another, compost heat, hydrogen?

Hydrogen gas burns extremely hot and would probably require an engine constructed at least in part from some kind of special high temperature alloy.

Anyway I just checked my email.

I had been corresponding with Sunpower recently in regard to the availability of any Stirling engine, but all they sell right now is Cryocooler, but the representative did recommend another company:

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So I filled out a contact form on the website and just got back a response:

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The same question I would have asked, and have asked.

Now I'M not sure how to respond. First, I'm not really in the market for an engine right now and second, I have a wood/coal stove, but I'd probably use solar if possible, and propane gas could come in handy, - decisions, decisions.

I also cringe at what I imagine might be the cost of a custom built engine.

Anyway, so who has an answer?

Or who has a request for a Stirling using WHAT as a heat source?

[Tom Booth]

I got a letter (email) from Microgen with a PDF illustrating their various engines

Just a small section of the brochure showing the 1 kw engine with various heater head options:

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Looked quite interesting, but when I asked about prices, I got back a rather bizarre email.

She had asked if I was "People's RESOURCE center" and I said no, my YouTube handle is people's research center and sent the link

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When I was just starting to think there was some light at the end of the tunnel.


Why can't I "just buy" a stirling engine?

Anyway, not sure where this is going but I wrote back, I can't "send" my YouTube channel with dozens of videos and it's irrelevant anyway.

I have no specific plans involving IP or NDA's. My plans for any engine would depend largely on the price and the capabilities of the engine itself.

I might run some tests or do a product review and I know a lot of people (Amish) in large communities living off grid who would certainly be interested etc. is what I wrote.

And, why does your company not just have a price list and some method of purchase, like most other products?

[Tom Booth]

Well, I found the same PDF file / brochure Online, on the Sunnytek website (Sweden)

http://www.sunnytek.se/fixarsidan-for-d ... latest.pdf

Search the sitemap for some additional "microgen" product brochures (way down on the page)

http://www.sunnytek.se/site-map/site-map.html

Including a 2kw version Stirling.

There is also an English website (partial at least):

http://sunnytek.se/sunnytek-web-site-in-englis/

The Sunnytek site(s), seem a bit dated possibly (?)

For example, it is mentioned "In 2017, a new model of 2 KW power is coming."

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I'm feeling a kind of vague hopeful skepticism. As I've been through this several times before with a number of other companies apparently selling Stirling engines or Stirling residential CHP systems (combined heat and power).

It all seems legit, until it comes to actually purchasing an engine or a system, then it all begins to look like some sort of facade. No prices, no order forms, contacts/representatives fade away.

I need to divulge my intended use before I can get a price? Non-disclosure agreement?

Is this some kind of elaborate prank? Has anyone in here, or just passing through, ever seen an actual, physical Microgen engine or managed to obtain one or so much as get an actual price quote?