On Tue, 27 Sep 2005, Russell McMahon wrote:

>> ... Anyway it would cost less than half to build, compared to what a 500 
>> Watt Stirling costs (5000 EUR).
>
> Why? People seem to want to dismiss Stirling engines for all sorts of 
> reasons but most seem to be based on false impressions or uncertain 
> assumptions. What it costs to BUILD a 500 watt Stirling engine is 
> quite different from what it presently costs to buy one. The 
> difference between cost and selling prices

I don't want to dismiss anything but the turbo has a potential of 20:1 
Watts/$. My reference price and power was from here:

http://www.geocities.com/Viebachstirling/

Pages are in German.

> includes such factors as marketing, suitability for niche markets which will 
> tolerate higher profit margins and the consequent "what the market will bear" 
> costings. If you are making say 10% profit then if you double the selling 
> price you can afford to sell somewhere around only 10% as much before you 
> lose money. Fixed costs, volume sensitive costs, size of plant and many other 
> factors apply but as a general rule, for a niche market product the true cost 
> of production is quite different from the selling cost. It's only when you 
> get a highly competitive commodity market that the two approach each other 
> closely. (The invisible hand at work :-) ).

I agree 100% but getting things done implies not disregarding the W/$ 
ratio. I was unable to find a better deal for a Stirling on the Internet 
(better than $10/W, as in the Vierbach linked to above). It may well 
turn out that the turbine will cost more. A better figure of merit would 
be Wh/$ considering engine life. E.g. a new Vierback will be EUR5000 but 
a new turbine once everything else is in place will be $300.

It is clear to me that at this time this is a wasteful experiment. But 
someone has to start somewhere and who knows where it will lead.

Peter
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