DIY CHP

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Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Fri Jan 17, 25 9:52 pm Post subject:

https://youtu.be/QH8RBcyFDe4?si=lBK8oL4gZ9AH_V_e

It says in this video that the special Flexure springs are patented, but that is a bit misleading. Such springs are nothing new and there are dozens of variations. The engine I have was developed using taxpayer funds as part of a government program so cannot be patented by law.

Qenergy, I suppose, developed a slightly different style spring so they could claim a patent but the basic Stirling Engine technology goes back to the 1800's

Probably it is obvious it infuriates me that these engines could have been available and mass produced back around 2009 when the one I have came off the production line but now we still have to buy the gas and oil while these engines are only used on gas and oil pipelines!!!

I don't think the government program that spent hundreds of millions of dollars developing these engines was intended to simply further enrich the Oil and Gas companies.

Mistress Rose

Joined: 21 Jul 2011
Posts: 16070

Posted: Sat Jan 18, 25 8:30 am Post subject:

It sounds fairly typical of government contracts I am afraid. It was probably decided that it was too expensive for the results obtained so far.

You might be able to get the thing started using charcoal and bellows as iron used to be melted using charcoal, but you will need to add plenty of air. By the sounds of things you will also need to use plenty of cooling water too. Doesn't sound practical for home use though I am afraid.

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Sat Jan 18, 25 5:10 pm Post subject:

Mistress Rose wrote:

It sounds fairly typical of government contracts I am afraid. It was probably decided that it was too expensive for the results obtained so far.

That is pretty obviously not true IMO.

While INFINIA publicly declared bankruptcy they continued producing the engines under gov. contract for military use, then later re-emerged as Qnergy as already seen, producing nearly identical engines for use by the oil and gas industry for remote power applications.

One company, a competitor with INFINIA for government contracts Microgen : https://www.microgen-engine.com/
also produces units for the oil and gas industry and CHP units in countries that allow it. I was told by a representative that there are, or were, until very recently, import restrictions that have prevented US sales.

IMO, the cost is being kept artificially inflated and the use restricted.to areas that do not threaten the economic and political status quo.

Qnergy talks about how their engine can run on biogas from pig manure, while absolutely true, you don't actually see them marketing any systems to farmers, it's just hype.

These engines are fundamentally so simple, you can find dozens and dozens of people on YouTube building models out of tin cans and rubber gloves and coat hangers.

https://youtu.be/r9lYsW0Df08?si=M0hC5aFFIPRztkii

https://youtu.be/CXsFNPmjluo?si=GvC7n0Q_cvBc4TYE

There is no real justification for one of these engines costing hundreds of thousands or millions of dollars.

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Sat Jan 18, 25 6:16 pm Post subject:

Another company producing Stirling CHP units was Sunpower. But they were acquired by a multinational conglomerate Ametek in 2013

https://en.m.wikipedia.org/wiki/Ametek

and were afterward directed to only produce their engines for NASA/space applications or as cryocoolers, but not for domestic power production.

The reason is obvious and openly confessed, as seen in the previously posted video clip.

If you can sell the same engine to NASA, the military or the oil and gas industry for hundreds or thousands of dollars each, you have little incentive to sell the same engine to homeowners or farmers or individuals for any kind of fair and reasonable price.

Most if not all of these companies started out with high ideals and were actively producing engines for domestic CHP use for a short time before, they sold out.

This was around 2007, a pretty fancy CHP was going to market for a few thousand dollars, about the same cost as a higher end refrigerator.

https://youtu.be/p-6hOOjxmNw?si=hYjysQsT1XyzVEvy

And years ago from Qnergy:

https://youtu.be/iKxRwJgo0d4?si=F548k5JHkfGCfgL_

But no more.

Mistress Rose

Joined: 21 Jul 2011
Posts: 16070

Posted: Sun Jan 19, 25 9:55 am Post subject:

Having worked in the defence industry for years, I have seen the cancellation of projects fairly frequently. It can be for a variety of reasons; we didn't always know why, but politics, price and availability of cheaper alternatives (not always ones that worked as well) were the reasons we were aware of.

In this case it seems that politics/ greed may have combined. However, the fact this particular one needs a very high temperature to get it going suggests this particular model is not of the tin can in the kitchen type or the sort that can be of a great deal of use at home.

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Sun Jan 19, 25 6:16 pm Post subject:

Mistress Rose wrote:

Having worked in the defence industry for years

Sorry, but appeals to ones own authority by anonymous posters on a forum carries no weight.

Quote:

, I have seen the cancellation of projects fairly frequently. It can be for a variety of reasons; we didn't always know why, but politics, price and availability of cheaper alternatives (not always ones that worked as well) were the reasons we were aware of.

For example?

Actually never mind. Unless you know something specific to this project (INFINIA Power Dish) your speculations regarding other alleged projects you've allegedly seen are largely irrelevant.

Quote:

In this case] it seems that politics/ greed may have combined. However, the fact this particular one needs a very high temperature to get it going suggests this particular model is not of the tin can in the kitchen type or the sort that can be of a great deal of use at home.

It is fundamentally identical to the "tin can in the kitchen", if the tin can model is of the "free piston" type. A free piston Stirling engine is a free piston Stirling engine.

Friction free flexure bearings can be made out of balloons, rubber bands or latex gloves as well as some space age alloy and serve the same purpose. Just as you can have wheels on a toy car or a semi tractor trailer. A wheel is a wheel.

Those type of solar dish Stirling generators could be planted in the ground anywhere like trees. Produced in various sizes with various power output. INFINIA also produced a smaller 1000 watt model.

INFINIA was attacked on many fronts. The withdrawing of funding is a matter of congressional record. INFINIA representatives appeared in Congress to explain the consequences of the cancellation of that funding and how it would ruin them.

Some supposed Native American tribe came out of the woodwork and sued them on the grounds that the proposed installation site in the desert was some sacred tribal land, the Railroad sued them on the grounds that the parabolic dish would blind train conductors causing train accidents.

Anyway, I'm with the OP: DIY CHP

Build your own.

It doesn't have to be built to NASA/Military specifications like the INFINIA models. Those were built to deflect bullets and survive bomb blast and/or withstand extremely harsh or unusual environments, including deep space.

https://youtu.be/4AsnE9kwyDw?si=A7BH1BIpm_rtYbf6

A functional Stirling engine can be made from scrap to run at various temperature ranges and doesn't necessarily need to be "free piston".

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Mon Jan 20, 25 3:39 am Post subject:

Mistress Rose wrote:

Having worked in the defence industry for years, I have seen the cancellation of projects fairly frequently...,.

The "project" BTW was not cancelled, as far as it's military contracts were concerned, INFINIA fulfilled their obligations and a large array was installed at Tooele Army Depot in Utah. Still visible via Google Earth:

https://youtube.com/shorts/ziMYKGWl9Tk?si=gK1sWOrin-z-ntUN

Judging by the visible tire tracks all around the facility, and between all the Power Dish units, apparently still maintained.

It was only INFINIA's ambition to branch out into the mass production of domestic CHP units that was "cancelled".

The automakers were understandably infuriated as they had already renovated their factories and tooled up, and infact were begining production. The funding that was pulled, to assist the automakers was unrelated to INFINIA's military contracts. It simply would have made the engines available to everyone to stick in their back yard like a satellite dish to power their own homes or businesses at a reasonable cost.

There is no reason one of these engines could not power a home just as well as providing remote power on an oil or gas pipeline or on a space station.

The problem with CHP is in the old Carnot theory of heat engines, where it is imagined that heat passes through the engine like water powering a mill wheel so the heat, or water, comes out the other side.

Stirling engines don't actually work like that. They do not produce "waste heat", they convert the heat into other forms; mechanical "work" and/or electricity, so that there is no "waste heat" left over to make hot water for CHP.

The design would have to focus on heat storage, such as in a sand battery, then take heat from there to heat hot water, OR to run the Stirling engine for electricity.

Trying to get heat from a Stirling heat engines is like trying to get gasoline from a car engine. It doesn't work. The heat is "consumed" as "fuel" in the Stirling engine, the heat does not pass through the engine and out the other side.

The INFINIA receptor was originally designed for electrical production only. (As in the Tooele installation). The larger engine I have has a kind of duel receptor, for direct solar heating of the water as well as powering the engine.

The problem is, the water jacket surrounding the receptor tends to rob heat away from the engine before it can even get started. A conventional heat source is too diffused, spread out, not concentrated to a point as is possible with sunlight via a parabolic dish.

Probably a small gas torch flame confined to the center of the receptor area would work better than a spread out stove top type burner so as to heat the internal engine rather than the surrounding water cooling jacket.

Unlike the above illustration, in reality, for solar use, there is a secondary cone in front of the receptor plate that reflects the sunlight into an even more concentrated area while blocking or shading the peripheral area where the liquid cooling jacket is located.

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Mon Jan 20, 25 6:40 pm Post subject:

Hairyloon wrote:

It would be better with a Stirling engine, but I can't simply pull one of those out of a handy scrap car.

Does anyone know what has become of "Hairyloon"?

It was his interest in Stirling engines that lead me to this thread.

Hairyloon

Joined: 20 Nov 2008
Posts: 15428
Location: Today I are mostly being in Yorkshire.

Posted: Fri Feb 07, 25 10:04 am Post subject:

Tom Booth wrote:

Hairyloon wrote:

It would be better with a Stirling engine, but I can't simply pull one of those out of a handy scrap car.

Does anyone know what has become of "Hairyloon"?

He drops in occasionally...

Hairyloon

Joined: 20 Nov 2008
Posts: 15428
Location: Today I are mostly being in Yorkshire.

Posted: Fri Feb 07, 25 10:18 am Post subject:

Tom Booth wrote:

I found this solar Stirling engine for sale on eBay.

How much did it go for?

dpack

Joined: 02 Jul 2005
Posts: 46302
Location: yes

Posted: Fri Feb 07, 25 12:23 pm Post subject:

hi there mr H, good to see you here

re a decent use for the thing, rather than a huge mirror in a desert a rocket stove in an arctic forest might be a good energy harvester

if it is sunny PV etc works well with modern kit, a Swedish winter is not PV friendly and gasifying wood to run an ice genny or cutting enough wood for steam engine is a pita without it being -30Cand dark 23 hrs a day
dragging the kit around is a problem with steam or gas/distillate production

ps the huge mirror things are huge and impractical for small scale or mobile but you do get a constant supply of semi cooked birds

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Fri Feb 07, 25 4:33 pm Post subject:

Hairyloon wrote:

How much did it go for?

Actually, I misspoke. I did not buy it on eBay directly myself. Someone posted to the Stirling engine forum that they had bought it on eBay but never did anything with it after having it in storage for 3 years. He never said exactly what he paid, he just thought I should have it. (I think he may have said he paid about $3,000)

My main expense was the long road trip from New York to Colorado with my wife to pick it up. The guy did not want to ship it and the shipping would have likely cost more than the trip, so we made a vacation out of it.

I believe, from the model number "Y" something, it had been manufactured for a large milk processing plant in Yuma Arizona.

https://www.encapdevelopment.com/gh-dairy.html

A few (or at least one) were sent to various universities for testing and were never installed for actual use at the dairy, I have one or those "Test" engines.

Hairyloon

Joined: 20 Nov 2008
Posts: 15428
Location: Today I are mostly being in Yorkshire.

Posted: Fri Feb 07, 25 8:56 pm Post subject:
What is it rated for?

tahir

Joined: 28 Oct 2004
Posts: 45695
Location: Essex

Posted: Fri Feb 07, 25 9:55 pm Post subject:
Bloody hell, how you doing?

Tom Booth

Joined: 06 Jan 2025
Posts: 11

Posted: Sat Feb 08, 25 1:03 am Post subject:

Hairyloon wrote:

What is it rated for?

The electrical output is supposed to be 3000 watts.

I believe the voltage is quite high. Probably around 400 volts high frequency alternating current. The output needs to be rectified and put through an inverter to be usable.

I just picked up a new propane burner with a compact nozzle, like this:

that might concentrate the heat to a small enough area to get it running, so maybe I'll be able to get some actual output readings soon.

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