Sterling Heat Engines

Has anyone ever considered using a Sterling Engine powering a generator using hot water from a boiler or flue gases as a heat source? I can only find model engines or very expensive ones not readily adaptable or affordable to the average homeowner. Steam engines are not safe to leave unattended. From what little I've learned the Sterling would be much safer and almost automatic.

They are pretty sophisticated pieces. While their theoretical efficiency is very high, they are rarely practical and I'm not sure why, it could be the cost. They do have to be fairly large for a small power output and run best at a fixed rate. They will run on almost any heat source though. What did you have in mind?

Hi Ian, The pie in the sky idea is operate the Sterling generating about 20 amps of heat from my boiler with the waste heat from the Sterling helping to heat the house. Why just make heat if you can have electricity too. In theory it sounds good but without mass produced hardware that is affordable it probally isn't practical. Who knows, maybe there is someone out there that has worked it out. Maybe you could use a grid interface like they use for solar panels and sell any excess power to the power company. I don't have an in depth knowledge of the Sterlings to know it it would be feasible.

Here's one that runs on wood pellets. Don't know how much it costs, but I'd say it's pretty expensive.

Thanks for the link. I checked it out and sent them an e-mail. I bet it would be out of my reach finacially but if you don't ask you'll never know.

Would you let us know what you find out? I found some plans online for making a sterling engine from tin cans... probably not what you're looking for

This is very interesting stuff!

Wikipedia has a great article on Sterlings. Sounds like hot water wouldn't create enough heat differental between the sides of the engine to do useful work. Off the cuff I'd say it would take fire box temps on the hot side. Needs a serious heat source to put out useful power.https://en.wikipedia.org/wiki/Stirling_engine

Use the coal fire as the high side and cool off the low side with your heating water. Seems that a differential of 2500 degrees far. should be a big enough difference. By the way, the pricetag on these engines are astronomical. Have you found a cheap source? Scott

Did you see how much even the little display engines or DIY project ($150), the Brass one is like $2000.
http://www.stirlingengine.com/

stokerscot wrote:Use the coal fire as the high side and cool off the low side with your heating water. Seems that a differential of 2500 degrees far. should be a big enough difference. By the way, the pricetag on these engines are astronomical. Have you found a cheap source? Scott

I found this on a stirling site.
"A good general guideline is that if the hot side of the engine is not at least 500 deg. F. (260 deg. C) the engine will be too bulky for the amount of power it puts out."

I think one could be built fairly cheap from scavenged parts. It isn't as complex as a steam or ICE

We need more info, plans and drawings.

This looks like an interesting book:

http://www.stirlingengine.com/ecommerce/product.t ... duct_id=84

Chapter 6 for a taste of how it reads:
**Broken Link(s) Removed**Based on a quick scan of the pictures, looks like this particular science project determined that the size of a Stirling Engine for 5 HP is almost 15:1 bigger when compared to a normal 4 stroke internal combustion engine.

I'm impressed by what I read here. Time will tell if they can deliver at prices that work. They seem focused on solar but the technology could turn any heat source into electicity.
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This is a very interesting topic to me. I have been doing a lot of reading about steam electric generation and some of the best steam engines were made in the early 1900s.
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Just some other reading material. http://www.mikebrownsolutions.com/stmpwr.htm

One more link and I'll be quiet for the night.
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