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  • Will This Work?

    Posted by David Foster on December 17th, 2012 (All posts by )

    Peter Thiel put $300K into this company, which seeks to capture waste heat from power generation facilities (and other forms of low-grade heat) by artificially creating very tall vortices. The system works something like a very tall chimney, but without the expense of constructing such a chimney. Simple explanation here.

    (When I wonder “will this work?”, I don’t mean at a technical level..sounds like experimentation has demonstrated that it will, at least at a small scale…I mean “work” in a commercial sense)

    They cite 35% as a typical efficiency for a thermal power plant (which sounds about right) and estimate that their system could recover 20% of the now-wasted heat, resulting in an overall plant output increase of about 40% with no increase in fuel consumption. However, I’d make the point that new combined-cycle power plants are considerably more efficient–GE is claiming 60% for some of their “H” series machines…which is obviously a good thing but leaves less wasted heat to be recovered. Still, there is a lot of rejected heat even from combined-cycle turbines…and not all power plants are going to be combined-cycle..for one thing, I don’t think CC plants can use coal unless it is first gasified.

    Lots of issues between development and large-scale deployment, of course..costs of large-scale systems are hard to estimate until you actually build one and operate it for a while, and I also wonder about public acceptance (and aviation safety/traffic implications, were these plants to be built out densely.) It’s a very creative concept, and I’m glad to see Thiel putting some money behind it…lots more will be needed to reach a commercial level.

    I’ll be watching this with interest.

     

    15 Responses to “Will This Work?”

    1. JeffC Says:

      cool idea … but they don’t say how they get the power out of this vortex they have created … the spining air may look powerful but it is just spinning air … put a turbine into that flow and lets see if it can sustain power generation … since they make a point of not showing any generating turbines I’m going to go out on a limb and say that the process may break down when you try and extract real power from the vortex … seems like a feasable idea for improved cooling though, not sure how much real power can be generated …

    2. David Foster Says:

      They did show a turbine somewhere in the details on their site.

    3. IGotBupkis, Legally Defined Cyberbully in All 57 States Says:

      Hrmmm… I recall a wind power concept I encountered in, IIRC, a WSJ article about 15-20 years ago… the notion was to use a tall chimney (think “Nuke cooling tower”), then mist water up at the top. Water absorbs heat from the air, which then drops downward due to increased density and “weight”. Place turbines at the bottom to derive power from the outflow.

      It’s the only wind generation scheme I’ve heard of that struck me as potentially functional, since it’s basically making its own wind. I have no idea if the idea was ever taken any further, or if there were problems (several come to mind — it’s clearly water intensive and you have to bring the water “uphill” — but I can think of several possibilities to overcome both of those — a big bore hole in the side of a mountain near a glacial runoff seems potentially effective, for example).

      This scheme sounds vaguely related. One wonders if some combination of the two might work — warm air derived somehow from the power plant at the top, mist, and derive power from the cooled air as it pushes down. The big question is how significant a volume of air you can get moving steadily, and how much real energy there would be in it. I’d think you could get quite the airflow going there.

    4. David Foster Says:

      IGB…you don’t need to add water to the air to cool it if the chimney is tall enough, because air temperature declines with altitude.

      See the company’s writeup on solar chimneys:

      http://vortexengine.ca/AVE_FAQ-solar-chimney.shtml#what_isasolarchimney

    5. setbit Says:

      I’m a strong advocate of substance over style, but a blatant lack of style is often an indicator of a lack of substance.

      The web site and presentation linked are just a mess. This venture has all the classic hallmarks of junk engineering.

      I will practically guarantee that unless this company gets some very talented help very quickly, they will lose every penny invested in them. Even then, I’ll bet they don’t have the engineering side of things thought out well enough to succeed even in a purely technical sense.

      Lack of attention to quality and detail tends to exhibit itself in all aspects of a person’s work, especially engineering.

      (Of course, having gone negative, this comment is almost sure to have an egregious spelling or grammatical mistake.)

    6. David Foster Says:

      Setbit..well, the site certainly doesn’t look to have been done by top-tier marketing people. (The same is sadly true of a lot of much larger companies as well.) Maybe Thiel’s involvement will result in some improvement on this score.

    7. Bill Waddell Says:

      Generating energy from waste heat is not new. My brother works for these guys (an Israeli company)

      http://www.ormat.com/recovered-energy

      They have been doing is successfully (and very profitably) for years.

      Setbit – you will have more respect for Ormat – they have a nice web site

    8. setbit Says:

      Bill,

      Setbit – you will have more respect for Ormat – they have a nice web site

      Attention to the basics of communication is a necessary, but by no means sufficient, indicator of competence.

      The main thing I see operating in Ormat’s favor is that their stated goals appear to be in line with their talent and experience. No promises to “make history!” like AVE, just a claim to have better mastery of the technology than the other players.

    9. Joe Wooten Says:

      I would bet the power conversion efficiencies will be low when scaled up for commercial applications. The fans used to capture the energy from the vortex will have to leave enough velocity in the vortex to enable flow to continue through the chimney. I would also bet the capital costs of building the system would be prohibitive and maintenance costs would be high.

      I have seen several methods over the years to capture the heat from a power plant condenser, including one scaled up to commercial size. That one was the campus power plant at the University of Texas and was built back in the early 1970′s. They had a combined cycle gas/steam turbine system and the neck of the steam turbine condenser was a freon boiler. The roughly 1000 BTU/lb steam exiting the turbine boiled the freon which was used to run several small freon turbines. Those turbines did not generate power, but were used to run pumps through reduction gears that pumped hot/cold water all over the campus for heating/cooling. It was a very efficient system, but the ME professor who was instrumental in building it told us in the Power Systems class that the capital costs for the freon system was too high for commercial applications. The payback was too long, and maintenance costs were high. At that time (1978), Freon was also becoming a big target of the enviro-whacko movement, but he told us other gasses, like propane or butane would work also, but understandably, the flammability of those gasses would be a problem.

      Also, the efficiency of an older nuke plant is about 33%-35%, a modern coal/gas fired steam plant is about 42%, and the newer nukes being built now will be about 36%-37%. There is a lot of latent heat in the exhaust steam of any steam plant, but the capital costs to extract that energy is very high, and is higher on a per kW basis than wind and solar, which is why no one is really pursuing these methods, as unlike wind/solar/biomass, there are no extensive federal subsidies for it. The one thing ALL these alternate energy schemes have in common is a prohibitive cost per kW generated.

    10. Joe Wooten Says:

      Bill,

      I would almost bet that the profitable plants Ormat has built involves processes that leave a lot of sensible heat to be extracted from the processes. A steam power plant uses all the sensible heat available in the steam, which is only about 35-40% of the total heat.

      For those who are not thermal engineers, snesible heat is the heat added/subtracted that will cause a temperature change, latent heat is heat that is needed to get to a phase change. In a nuclear plant, steam comes in from the reactor/steam generator at about 1200 BTU/lb and goes into the condenser at about 1000 BTU/lb, and the temperature drops from ~ 560F to about 90-120 F depending upon the season. A fossil plant has steam coming out of the boiler ~1400 BTU/lb and exits at about 1000 Btu/lb.

    11. David Foster Says:

      One approach to taking advantage of rejected heat is to use it for home & commercial heating purposes…”district heating”..see this link

      http://chicagoboyz.net/archives/6821.html

      …requires that the power plant and the places being heated are reasonable close to one another.

    12. Joe Wooten Says:

      Tough to do with a nuke plant. Not many folks would want one in downtown Chicago……

    13. Joe Wooten Says:

      Heck, these days, the enviro-whackos don’t want ANY power plants in the city. The last coal fired plant in the city boundaries was closed down, and there was nothing to replace it there.

    14. PenGun Says:

      I have about 1000 meters of mountain some 3 Km from my door. I walk up it once a year. You could lay a big pipe from the bottom to the top and get substantial temperature difference and stuff a turbine in it. Pretty simple and the mountain holds up the pipe.

    15. Vader Says:

      So they’re investing in artificial tornadoes? Too bad I already invested all my money in the locust hatchery.

      Jokes aside, so long as the exhaust is significantly warmer than its surroundings, yes — it’s waste heat and there is no Third Law prohibition on trying to extract more energy from it. The smaller the temperature difference, though, the less energy can be extracted from it.