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Kender Solar Engine

PostPosted: Sun Aug 30, 2009 12:17 am
by mikedmonds
Dear Forum,
Is anyone familiar with this one? It is a Stirling engine that uses a
turbine instead of pistons. Here is their website:
Do you think this is feasible? How likely do you think is it that they
can make it work as advertised?
They claim that the energy extracted by the solar panel produces more
energy than what it takes to drive the compressor to circulate the
helium, and results in: "The system produces 39 kW of power (47 kW by
the turbine, less 8 kW for the compressor). That is equivalent to 53
horse power, or enough energy to supply energy for 12 homes."

Kender Solar Engine

PostPosted: Sun Aug 30, 2009 11:22 am
by stan.hornbaker
"It is a Stirling engine that uses a turbine instead of pistons." Simply NOT true.

From their own home page they say "Similar to a heat pump or a Stirling engine." They do not claim it to be one! Take note that it is in development and they are looking for investment capital.

Response to Kender Solar Engine

PostPosted: Sun Aug 30, 2009 12:13 pm
by mikedmonds
I apologize. I am no expert on the technology. That's why I am looking for opinions!
Best regards,

Response to Kender Solar Engine

PostPosted: Sun Aug 30, 2009 2:23 pm
by stan.hornbaker
If you will do a little research on Stirling engines you will find that they operate on a gas, usually air but sometimes on helium or hydrogen. Never on a liquid/gas via phase transition. Follows is a link to Dr. Izz's online text book information on thermodynamics and Stirling engines.

Another is

Lastly try subject searches using the Yahoo search engine.

Response to Kender Solar Engine

PostPosted: Fri Jan 29, 2010 8:06 pm
by thomas_a_booth
You might be interested in this;

For the past few years I've been trying to design a Solar Powered Stirling Engine and kind of developed a "Stirling Turbine" by accident when trying to incorporate an "Air Cycle" cooling system (Which uses a Turbine to create your temperature differential). I came up with a couple designs I THINK might actually work.

Technically speaking, I guess it isn't a Stirling Engine, I don't know, but it does incorporate the Stirling principle, i.e. it has a displacer and displacer chamber of sorts to expand and contract air - acting as a "compressor" for the Air-Cycle heat exchanger.

I would very much like to hear anyones comments or criticisms on the theory and design.



I'm also discussing this on another Stirling Engine forum:

Response to Kender Solar Engine

PostPosted: Fri Jan 29, 2010 8:51 pm
by mikedmonds
Hi Tom,
Sounds interesting. Does it look like the Kender engine?

Response to Kender Solar Engine

PostPosted: Fri Jan 29, 2010 9:39 pm
by thomas_a_booth
"Does it look like the Kender engine?"

Not really at all.

It looks like the Kender engine there uses an electrically driven compressor. Mine uses a Stirling type heat driven displacer chamber as the compressor. The Kender engine uses a closed gas-cycle with compressed helium as a refrigerant. Mine uses an open air-cycle using plain old air as a refrigerant. The Kender engine prototype looks wildly complicated. My engine is relatively simple by comparison.

The key elements and the theory however appear to be the same. i.e. compress a gas (Helium or Air) remove the heat via a turbine (I use some of the heat in the compression phase to run the "compressor" since my compressor runs on a temperature differential, more like a Stirling Engine. Kender uses an electrical compressor) And use the cold produced to get your temperature differential between the extreme cold from the turbine and ambient air temperature.

All in all, my engine is simple enough that any model builder should be able to make a working prototype. (If the concept works that is)

The Kender engine has been in development for years, though, they are shooting for much higher energy outputs by using a compressed gas and extremely low temperatures which presents a lot of problems - like material issues.

So, in short, no, there is no visible resemblance but there is a similarity in principle. (i.e using a turbine to create a heat sink so as to extract energy from ambient air temperatures - like a Stirling Engine running on ice with the Stirling engine being used to run an "ice maker" that is used to keep the Stirling engine running on ice...

Sounds like, but isn't "perpetual motion". It uses indirect solar energy trapped in the atmosphere.

I tried uploading a drawing I made of my engine but it wouldn't upload for some reason, but you can view it here:

Response to Kender Solar Engine

PostPosted: Sat Jan 30, 2010 5:54 am
by stan.hornbaker
Since the Kender engine is NOT a Stirling engine it is NOT an appropriate subject or topic for discussion in these forums.

Any and all future posts are subject to removal.