> Russell, et all, will now argue the point. No arguments. I'll just point out a few 'facts' and be on my way to the church AGM :-) > Notice the date. It didn't happen. Again, stirlings are not > reliable. That, of course, very much depends. Their siameses twin, Stirling cycle coolers can be and are made as reliable as all get out. When your are being designed to live in a ComSat you have t be. > They are either A) inefficient and long lasting or B) efficient and > wear out > quickly. ... You seem to be, surprisingly, so I may still be asleep, which is entirly possible, confusing efficiency with power density. Properly designed and built built Stirling engines, ie not the numerous model ones whose designers have no idea about the absolute need for a decent regenerator for real purposes, are as about as efficint as anything around. What they are generally not, and what you may mean, is that they are not "power dense". ie they tend to be large in volume and possibly in mass for their power output. There are reasons for this, which is no excuse when comparing them against alternatives. But in an "alternative energy" world and for non-nobile applications this is often no big deal. Lifetime is an increasing issue as you attempt to improve volumetric power density. > They don't even have a C) option with high cost and both efficiency > and long life as far as I can tell. And yet people keep throwing > money into > them. I'm sorry, but at what point is that stupid? Something / one is stupid if you don't like its face. There are several good reasons to keep trying. But I'll not expand at length now, except to say that > How much money do we need > to waste on something that has been around for just about forever > and has > NEVER been cost effective? *WHEN* the big boys (or the little girls) finally crack the problems it will rule the world (tm) and replace many alternative systems BECAUSE the external heating feature allows any heat sourcem use of low grade and "waste" heat, better efificency in any give case than any alternative and ... . The mighty Philips organisation threw in the towel - but that was due to accountants and other issues. They estimated it would cost (AFAIR) 60 BILLION dollars to get it truly right. And that the payback period would be under 6 months once someone did. At that point nothing is stupid :-) ie once you achieve this holy grail it will be the biggest cash cow ever known. Which is not why the little guys do it. They have other motivations. Many are at least as sensible ones as James' drive to ride electric bike/car thingies, grow chickens, use solar panels etc. An interesting data point. NZ mborn and made Whispergen whose ad I posted recently are THE most succesful Stirling maker ever (depending on your metric) and in the process of gearing up to fill orders for AFAIR 100,000 or so Stirling engines. Why doesn't that count? (special circumstances notwithstanding) Russell. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist