MarkG:  Am not sure I follow your thoughts here regarding the claim that "the OSE guys seem to be emphasizing high thermal efficiency". The 'bump' valve piston steam engine design that is currently the only design on the OSE Wiki, is any thing but efficient thermally or mechanically. The same thing holds true for the single-axis electronic tracking strip solar collector design. Higher temperatures may translate to higher operational efficiencies for the specific engine they feed, but they are also always associated with the potential for much higher systemic thermal losses as that is just the nature of the heat energy beast.

Translation of mechanical reciprocating motion into rotary via wrist pins and cranks is inherently fraught with friction and parasitic power losses with their attendant increased maintenance demands, not to mention all the resources required to manufacture the needless mess to begin with. Why cranks were even included in the design when the OSE emphasis is on hydraulic interfaces is an interesting insight into group mentality. On the solar side, while cheap electronic tracking controllers may now be available the problems associated with maintenance of an electro-mechanical tracking system which now requires an electrical power sub-system still exist, especially ones exposed to all weather conditions such as extreme wind gusts, not to mention tornadoes, which can simply rip such mechanisms apart or just toss trees on them. And when things are going well and the system is producing temps up to 500 degree C, what are the thermal losses going to be from the transport system and/or the called for 3 day storage system? Large delta-Ts create very large problems, which like the fabled Sword of Damocles, are a threat constantly dangling over your head.

In regards to your concept of putting waste heat to use, this seems to be part of holistic or integrated farming or whatever the term is. Although this term doesn't seem to be specifically used by OSE it is definitely implied in statements such as: "The most important feature of the Global Village Construction Set is its nature as an integrated tool-set or ecology of products that fit together like a Lego set or jigsaw puzzle for building real infrastructures of communities.", "Imagine that now we could transcend this game – by using modern technology to convert sunlight to sustainable energy (solar, wind, biomass, water, others) to process the abundant “dirt and twigs” under our feet into the substance of modern civilization."

Your concept is certainly valid but the specific means to accomplish it of course depends on what avenues OSE finally chooses to follow in regards to energy collection/generation/distribution. For instance instead of using a dual system of oil and an OCR which is somewhat complicated, there is a 'proven' option to just use air which provides for exactly the low temperature thermal system you seem to be after.

The fullest expression of this concept is the liquid air system referenced, although not discussed, in this Energy section by Beluga. This is not new technology, but rather can be traced back to the 1890s when air was first liquefied by Linde, I believe, and in a few years Germany had a huge industrial stockpile of liquefied air that supposedly no one understood the reason for. Today of course large liquid air based electrical generation facilities have been the focus of much construction activity supposedly as grid backup installations. The minimal press coverage this activity has received is related to the fact that they are efficient durable scalable environmental energy extraction plants. If the public ever understood exactly what that means, then the old tired argument against compressed air power systems being nonviable because the heat of compression is always lost and that the air freezes when released from the pressure vessels, would die the idiotic death it deserves.

For instance, lets say that in your scenario instead of using an OCR for heat recovery from a steam engine a system is implemented using a compressed air power system. To generate power the expansion engine of your choice is set between the great out doors and the compressed air tanks. Up-stream of the engine is a heat exchanger through which the hot air produced by the waste heat from the steam engine gives up its excess heat to the compressed air which allows it to recoup its pre-compression energy. The re-energized compressed air then powers through the expansion engine without freezing the poor thing allowing it to run a multitude of applications.

Simple reliable scalable expansion air engines of the basic piston design everyone seems to love, can be manufactured at a much lower cost than steam engines and can be used for almost any application. Air conditioning and cold storage needs are directly addressed, and work shop tools can be compressed air based which is pretty much the norm anyway. Passive hot water flat panel systems can be backed up by heat pump air-to-water heat exchangers. And speaking of water, the most economical, low maintenance, dependable DIY water pumping system known is the air lift system, which in conjunction with water aeration makes a very desirable package.

This is all simple proven standard compressed air / refrigeration / heat pump design minus proprietary exotic refrigeration fluids.

The sweetener with a low temperature energy collection heat pump system that no other system can match is that the storage vessels themselves, not to mention any return lines, are un-insulated energy collection devices as well. Instead of a high temperature energy system subject to continual heat losses, a low temperature system collects environmental energy continuously 24/7. Paint it black, put it in a green house enclosure, and step back. If you wish to augment it with flat plate solar collector panels or under-ground piping, have at it. And to top it all off, industrial systems don't even use mechanical compressors but rather venturi systems with no moving parts and almost zero maintenance.

Air, like sunlight, costs nothing, it can't be broken, it isn't toxic, and our atmosphere is the largest most accessible solar energy storage medium on the planet.

The question then is what to use for producing the initial energy to power the air compressors to begin with. I probably shouldn't give in to humorous impulses but what the hay - if it isn't fun why bother. Here is another OSE quote: "All wealth comes from sunlight, rocks, soil, plants, and water - the abundant feedstocks of modern civilization. We are creating an open source toolkit that allows people to convert these resources directly to a modern standard of living - at a cost of no more than 2 hours of work per day. This is an ultimate standard of human potential.... (OSE: Strategic_Plan_2_Ambitious.htm)"

In the spirit of that vision of excess leisure time and zealous dedicated community members, one option could be summed up by a cartoon of two lines of OSE staffers facing each other over extended handles similar to the old fashion see-saw like fire department water pumpers. The compressor handles are blurred with the flying effort, and the caption reads: "Marcin, get your butt down here, the induction furnace is coming on line and we need another erg!!"

Well, if that doesn't get me kicked off the forum nothing will.

MarkG:


My apologies for seemingly going somewhat off topic in my previous comment. It seemed, as I mentioned, that you were attempting to look at steam engine design from a more holistic perspective, which I agree with. However my perspective was apparently a step or two even further back, which perhaps made my comments rather irrelevant to your concerns.