James will be expecting this ... :-) > I keep hearing about cold fusion, sterling engines, fuel cells, air cars, > bio fuel... Every one of those has /fatal/ flaws. That's a strange mix. Cold fusion: As yet unknown technology that is hoped to be available and viable. A core of serious competent methodical researchers with as yet unproven results after decades surrounded by cloud of unknown magnitude of con men, sincere free-energy people with no grasp of physics and various camp followers > sterling engines Things that run on silver? OR a proprietary cycle engine that uses expansion of metal rods (really) >> Stirling engines No fatal flaws. Various engineering challenges. If you want a very good summary of Stirling engine development from about 1850 on an an utterly superb overview of what's involved in developing and refining small (100W range) Stirling engines with *demonstrated* lifetimes of over 50,000 hours (8+ years) continuous operation by 1999, and probability of survival figures of 13.2 years at 99.99% and 21.5 years at 99.9% by 2006, see *** SUPERB *** =3D=3D=3D> http://gltrs.grc.nasa.gov/reports/2007/TM-2007-214804.pdf These are niche no holds barred, almost cost counted designs with no contacting surfaces and heater head creep being the dominant failure consideration. They will not power your laptop any time soon (unless you are on the first Saturn flyby manned mission) BUT with results like this, trickle down and "look over the shoulder" copying will lead to stunning open market products. (Just reading this paper tells you, amongst many other things, what flexure material works best, and why, what challenges you face in heater head design, how hot the big-boys run and for how long and what happens, and what to use to glue your magnets to the linear alternator and that you can make it work 40% better than the manufacturer claims.) External combustion (like Cyclone engine), runs on most thermodynamically efficient cycle possible (unlike Cyclone), Large number in operation in many applications. Main issues are achieving good power densities at acceptable cost. So far viable mainly where either superior efficiency and performance are more important than cost or where other special attributes make them attractive. eg external combustion, no combustion (molten salt etc), high efficiency, silent operation etc. - Used by NASA for decades for deep space applications where the alternatives are inferior. Has demonstrated - 25 kW grid power delivered dish Stirling engines, the world's most efficient sun to grid efficiencies yet seen, proven in field trials over several decades at Sandia labs, small scale (around 100 units x 25 kW) demonstrations now running with funding being sought for square-mile scale installations in California and elsewhere. - Thousands of Whispergen cogen units (tens of thousands?) in long term field use in domestic marine applications and ongoing "advanced field trial" advice re $300M European CHP contract. (stay tuned). - Used in a small number of submarines for super silent "Air independent propulsion". eg Swedish Kockums. http://www.sesusa.org/submarine.pdf 75 kW, 14 days at 5 knots. NASA are due to trial a 40 KW fission (James HAS to love it) to Stirling Moon / Mars power source in 21012.. http://www.nasa.gov/centers/marshall/news/news/releases/2009/09-069.html More ... > fuel cells Extremely good now. Getting better by the year. Too expensive at present for mainstream use. Used by NASA as main Shuttle electrical power source since inception. Direct Methanol + air cells available now - priced well enough to be viable for niche portable applications. Current requisite fuel purity an issue under very active investigation. Ongoing substantial improvements in PEM membranes continues to improve many versions. Will be a very practical product in many applications in the 0 - 10 year ra= nge. > air cars, Say what? No doubt thrown in there for fun or to confuse. I'd swap my mouldering MR2 Supercharger for a Cyclone powered air car if I could find one. (Finding the MR2 is easy). > bio fuel This from a green tinged one ? :-). [[I'm also "green tinged" but it's not always apparent when pragmatics are being considered.]]. Also essentially orthogonal to the Cyclone. The Cyclone would run on biofue= l. Biofuel has its place and is fully viable as an energy source BUT if it is to be considered competitively it needs to be compared on a fully costed unsubsidised basis. Usually costings are so biased by political considerations as to be unable to be easily compared*, but its clear that biofuel is not a major contender as a petrochemical replacement and faces more than stiff competition from other alternative sources. major issues are available land resources, costing of alternative uses,efficiency of conversion and energy inputs required. * As is the case for 'certain other" "less green" proposed energy sources. > THIS Cyclone Engine is what we should be getting excited about. Efficienc= y > between gas and diesel, burns ANYTHING cleanly and completely. No NOx. No > oil, no transmission, low maintenance. >From their site: It's a steam engine. It has valves. It doesn't need lubricant because it uses water as its lubricant. It can run from waste heat sources down to 500F (many would love waste heat that hot) None of those are disqualifiers per se. But there have been many prior closed fluid steam engines, Rankine engines will be with you always, water as lubricant is a good trick if you can do it (gas with no touching parts is better and NASA have 8++ years of operation to demonstrate that it works). There are many small engine that will save the world wannabees. I will be very pleased when/if one succeeds. So far none have. Stirling is doing as well as anything in the external combustion race, so far. Mr Diesel's fine concept is arguably the market leader in internal combustion so far. Not as good as Mr Stirling's products in efficiency. but vastly cheaper to make. 500F source heat allows about 2;1 temperature ratio or 50% Carnot efficienc= y. Actual overall efficiency will be much lower. Hopefully in the 10%-20% range. Maybe less. A Cyclone engine will hopefully be sold for substantially less than an equivalent output Stirling engine. And will hopefully be more compact. > Most of all: It's REAL! > http://www.cyclonepower.com This was about as real http://green.autoblog.com/2009/07/08/blast-from-the-past-nasas-stirling-pow= ered-amc-spirit/ Very real. I'll have one (if free) http://www.stirlingengines.org.uk/manufact/manf/misc/subm.html http://www.sesusa.org/submarine.pdf 1988 precursor: http://trid.trb.org/view.aspx?id=3D432895 If you EVER get an opportunity to visit this museum do so. THE best technical museum I've ever seen. 1978 precursor Scant on information. But very real. http://www.whispergen.com/ Russell's photos: Model Stirling Engines NOT Russell's models http://bit.ly/StirlingEngineModels Inside a Whispergen (cutaway of real unit - "operates") http://bit.ly/WhispergenCutaway Bonus - StormRider Wind turbine - 14 photos, many similar. Some show closeups of centrifugal pitch control mechanism. http://bit.ly/Stormrider_14photos StormRider home page http://bit.ly/StormRider Russell McMahon --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .