>From far off* Ningbo. (* or not, depending where you are.) 1. The first sentence in the article is a lie. Whispergen beat them to it by some years - and there have probably been diesel fueled co-gen grid tied units before that. 2. If you read what was said about 100% and then what Olin said you'll see he just got out of be on the wrong side :-). His statement was essentially correct as the 100% poster neglected to add "efficiency" at the end of thei= r sentence. 3. Similarly Olin was essentially correct and rifle loading again when he swung back the other way - read the words carefully in each case. Olin is b= y no means right all the time, but when he makes apparently ludicrous statements check the semantics. If the semantics are OK he may just be bein= g ludicrous :-) - it happens sometimes. 4. Deciding whether efficiency can be > 100% requires you to define efficiency in advance. Heat pumps can in fact deliver a net gain in available energy wrt energy in= .. This is NOT simply a "steal it from somewhere else and its zero sum all round" - it's a real gain - BUT does not break the laws of physics (as ye canna). It works by piling spare heat energy on top of existing heat energy rather than creating it from another form of energy, as is normally done. If you use electricity to provide electrical resistance heating the energy provided "stands on absolute zero. If you use a heat pump you take packets of energy and stand them on top of energy which is already standing on absolute zero. So tin =3D input temperature degrees Kelvin. tout =3D output temperature Net energy "multiplication ratio" =3D tout/(tout-tin) (E&oe brain says fi= rst to feels more like ti) So for eg a heat pump outputting at 27 C =3D 300K and input at 0C =3D 273 K (freezing point of water) the theoretical max gain =3D 300/(300-273) =3D 30= 0/27 =3D~ 11:1. As the "lift" gets smaller the theoretical gains get even higher= .. In practice much lower gains are achieved - not through any fault in the physics but just because nature hates people getting a free ride and the little losses and inidealities grow rapidly as you get into higher lift ratios. This system could be used to build an APPARENT perpetual motion machine under certain conditions. Given three temperature regions Th Tm Tl with tm not too fat below Th and T= l as far below TH & Tm as possible. An eg Stirling engine could be used to drive a heat pump to deliver heat energy from Tm to TH and the engine could run off the differential from Th to Tl. (And probably also off Tm-Tl but that would spoil the apparent trick). Stirling Carnot efficiency is (Th-Tl)/Th and real world efficiency is seldo= m more than half that unless you are very very good at building Stiling engines. When Th-Tl gets to a certain differential the net gain will allow the system to run itself. But, it's not perpetual motion. 5. Whispergens originated in New Zealand, and are now being built in Spain for sale in the UK as home grid tied cogen systems pretending to be high efficiency boilers. They achieve greater than 100% efficiency where efficiency is defined as Operating_$_out/Operating_$_in by making use of several aberrations. North Sea gas has a much lower cost per energy unit than electricity. IF you own both the gas provider and the electricity provider (as is the case in the UK where this is being done) then you can use gas to run a home base= d Stirling engine, use the waste heat for the boiler and use the electricity in the home or send it to the grid. If your tie in tariff is 100% of normal domestic rates (as is the case in some administrations - and even greater than 1:1 in some others) then you can get a nice overall profit. The catch is the horrendously high price of the Whispergens. Apparently when all the boondoggles are applied the net result is profit positive, but you'd not achieve that simply using one as your own power and heat system. Russell --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .