Naturally Occurring Mineral Could Provide Efficient Thermoelectric Conversion

Since the days of the steam engines many different technologies have been designed to try and efficiently convert heat into electricity. Along with mechanical systems like steam engines and Stirling engines there are also methods of producing electricity directly from heat using thermoelectric materials — but so far these materials have proven to be either too expensive, to inefficient (or both) to be attractive in commercial settings.

Suzanne Jacobs has written an article for the MIT Technology Review reporting that a California company called Alphabet Energy is working on creating products using a naturally occurring mineral with thermoelectric properties called tetrahedrite which is much cheaper than currently used thermolectric materials.

Jacobs writes:

According to data released by Alphabet Energy, tetrahedrite costs about $4 per kilogram, whereas other thermoelectric materials cost between $24 and $146 per kilogram. For now, the company is focusing on stand-alone generators, but founder and CEO Matt Scullin says it’s currently working with car companies to see if tetrahedrite can be used to harness heat from car exhaust.

A news release from Alphabet Energy on July 1 2014 announced that Dr. Douglas Crane, Director of Thermoelectric Engineering would be presenting a report at the International Conference on Thermoelectrics, July 6-11 in Nashville, Tennessee. I haven’t been able to find any reports coming from the conference yet, but the program is available here.

Alphabet Energy has been working in the field of thermolelectic conversion since 2008, and in the past has worked on silicon products. The company seems to be still in the R&D stages and while the MIT Technology Review article says that Alphabet Energy’s tetrahedrite products will be on the market later this year, I can’t find any clear indication of that from the company’s web site or news releases. This could be a company to watch, however, especially if LENR becomes a cheap source of heat. Any way to cheaply convert heat into electricity could be very useful.

  • georgehants

    From Cold Fusion Now
    Ruby does it again
    Radioactivity Decreasing Effect of 4-5 nm Silver Particles on K40
    I report the most interesting experiment result in the above presentations in this article.
    Dr. Abe and Dr. Iwasaki had been announced the experimental results that
    the radiation of the contaminated soil was reduced when they added nano
    sliver solutions to the soil. This presentation showed the new
    experiment that nano silver particles could decrease radiation of
    radioactive potassium (K40).

  • Alain Samoun

    Talking about direct production of electricity without steam, is anyone reading invited to
    the BLP demo tomorrow?

  • Ophelia Rump

    Physics World: New generator creates electricity directly from heat
    A 40% efficiency could be possible

    “Practical thermionic generators have reached efficiencies of about 10%. The theoretical predictions for our thermionic generators reach about 40%,” says Mannhart. This figure also incorporates the energy needed to create the electric field.

  • Gerard McEk

    As long as the efficiency of these materials stays below 30% I do not think these will be used, unless the LENR COP increases a lot.

    • Ophelia Rump

      In truth, we do not even know the COP of LENR when it will first be introduced.
      So the question is increases from what? What is the current COP?

      Low for the potential COP is a much higher number than people conceive.
      A 6 or 7 would be world-changing but a fraction of a percent of the potential. A COP in the tens of thousand would till be fractions of a percent of releasing all the energy at the same time.

      • Gerard McEk

        When I talk about a COP of 10 for LENR, I mean that 10 times more energy (Wh or Joules) goes out than goes in. If you limit it to electrical energy going in and electrical energy coming out, than things change completely mainly because we can not generate electrical energy of heat in a very efficient way. Large power stations can reach the 60% at the best. Additionally, in contrast to fission energy or oil, gas or coal, LENR requires considerable input energy at this moment in time. That is why it is not easy to make a self sustaining LENR system, able to generate electricity efficiently. With two E-cat’s in series, each with COP of 10 (thermally) you can generate about 1 kW electrical and produce 19 kW waste heat.

        • Ophelia Rump

          Yes, I understand what you mean.
          COP is related to working energy, waste energy is no counted as far as the input to the next stage. Yes there are tremendous losses converting energy into work. In the case of the Thermo Electric Device in the article, it would not make sense to combine with LENR. the TED is too inefficient to justify even if the energy was totally free, it would just be a bad choice, unless you are using what is already wasted heat. There are better alternatives, significantly better, but not so much better that they satisfy.

        • Omega Z

          At a Given scale, E-cats with COP>10 with a possible 40% conversion efficiency to electricity is a strong possibility & very economical.

          Issues arise when trying to scale for private home use. Conversion efficiency drops to where the economics are highly questionable. Especially when figuring in the hardware costs.
          Thus, the reason I don’t get to concerned about home units not being available.

          What matters to me is the technology coming to market. Once available, Individuals, Science & Corporations will push technological boundaries to circumvent the efficiencies & cost barriers. None of this will happen until they can get their hands on it.
          NOTE: Some innovative, energetic young dude could build an E-cat emulation. Wouldn’t be that hard. Then start developing products that could make use of it once it becomes available.
          The Size/Shape, Output, & 24/7 operation state is pretty well known. Future improvements are possible even likely, but nothing of consequence. Anything pre-developed would be easy to account for once the basic development is done.

  • GreenWin

    “According to Scullin, Alphabet plans to complete a pilot installation at
    an industrial facility with a large waste heat source next year, with
    an aim of winning commercial customers by 2012.”
    National Geographic, August 2010

    Commercial products usually take longer than their inventors expect.

  • georgehants

    From Cold Fusion Now
    Dr. Edmund Storms Explains LENR — New Interview
    Sunday, July 20, 2014
    A brief description of our dialogue titled Nano-Cracks, Metallic Hydrogen, & Explaining LENR:

    • Bernie777

      Yes, a great interview!

  • Private Citizen

    “Scullin says that other thermoelectric materials have typically achieved
    about 2.5 percent efficiency in cars, but tetrahedrite could reach 5 to
    10 percent efficiency.”

    Prototype is probably less than 2% efficient. Operating temperature range, amount of thermal gradient needed (how cool must the heat sink be?), charge density, durability: all not specified.