Waste Heat = Free Energy: First-ever thermoelectric generator for industrial waste heat recovery making inroads in energy sector
- Published: Thursday, 22 October 2015
- Author: Lynda Harrison
Technologies to convert waste heat to energy have existed for some time, but only recently has a young scientist found a way to make it economic using platform silicon thermoelectric technology in a modular, scalable approach, and he’s initially targeting it for the oil and gas industry.
His company, Hayward, Calif.–based Alphabet Energy, rolled out the E1, the first industrial thermoelectric generator to convert waste heat into electricity, in 2014. The company says its core thermoelectric materials are third-party verified to be the most efficient thermoelectric materials ever made for waste heat recovery.
WASTE NOT Alphabet Energy’s E1 thermoelectric generator was designed to meet the needs of the oil and gas industry. It uses the company’s PowerModules, which contain patented thermoelectric materials that are solid state and have zero moving parts. (PHOTO: ALPHABET ENERGY)
“We’re just starting out,” says Matt Scullin, Alphabet’s co-founder and chief executive officer. “We only launched the product a few months ago, so this is a brand new product and we’re seeing good uptake so far and think that the growth will be very strong.”
The E1 attaches to an exhaust stack and uses Alphabet’s patented thermoelectric materials. It generates up to 25 kilowatts per 1,000-kilowatt engine, saving an estimated 52,500 litres of diesel fuel per year, per engine, says Alphabet.
Thermoelectrics use a temperature differential to generate electricity in the solid state, meaning the E1 operates with technology that has no moving parts and no working fluids and that requires little maintenance.
Last March, the company received $16 million in financing, led by its first customer, Calgary-based Encana Corporation.
The financing enabled Alphabet to launch the E1 commercially, though Encana has been piloting the technology on a one-megawatt midstream compression engine for about a year, says Scullin.
The company is addressing key industry pain points and helping energy-intensive industries generate reliable, remote power while reducing fuel consumption, operating costs and carbon emissions, says Kristian Bode, chair of IHS CERA Week Energy Innovation Pioneers.
IHS Energy, a global consultancy, named Alphabet an Energy Innovation Pioneer. The Energy Innovation Pioneers program recognizes companies that are developing technologies and delivering products that transform energy’s future.
NASA and the oil and gas industry have been using thermoelectric technology since the 1950s, but the needed materials, including rare elements, were extremely expensive, costing about $30–$60 per watt, so no one else could afford them, says Scullin.
But recently, Alphabet has made strides in developing silicon and the mineral tetrahedrite.
“NASA and the oil and gas industry have always used very expensive thermoelectrics in these smaller generators, and that’s why this sort of technology, while it’s good because it’s simple and reliable—solid state—never made it to large scale because it was too expensive,” he says.
(PHOTO: ALPHABET ENERGY)
Thermoelectric materials that generate electricity while in a temperature gradient must have the unique combination of high electrical conductivity and low thermal conductivity. Nanotechnology can now be used to lower the thermal conductivity of semiconductors whose electrical properties are excellent, the company says. Nanoscale features lower the thermal conductivity of the semiconductor and do not affect their strong electrical properties.
“The real breakthrough came in this tetrahedrite material that we’re using, which is out of Michigan State University, and this is really the first thermoelectric that’s been invented that’s both efficient and very inexpensive and very abundant. This has enabled us to think about these larger applications and delivering very useful amounts of power, on the order of tens of kilowatts, at a relatively low cost into a wide range of industries, including oil and gas.”
Tetrahedrite, an alloy of copper, sulphur and antimony, is a naturally occurring mineral, but it’s also the name given to any class of minerals that is similar to it that has the tetrahedrite crystal structure, so it is a material that was invented specifically for thermoelectrics, says Scullin.
“Thermoelectrics have actually been used in the oil and gas industry for many decades and are interesting because they’re so reliable, because they’re solid state, simple and therefore meet the sort of requirements that an oil and gas company demands for a piece of equipment in the field when it comes to strength, safety, reliability and simplicity,” he says.
Historically, the thermoelectric generators used by the oil and gas industry have been small, delivering only about 500 watts using a small propane burner to power things like supervisory control and data acquisitions systems and remote telemetry in areas where a high degree of redundancy was needed or there was no access to the grid.
“Generally speaking, there is a need for remote power, and unfortunately, those 500-watt generators don’t really provide enough to fully power the sites,” he says.
“Furthermore, at remote locations and midstream compression you have high costs associated with either running the grid—line power to the site—or in bringing in a diesel generator to generate electricity. So there is really a need to generate power at the site in order to improve safety and address environmental health and safety concerns in general, like lowering carbon emissions, reducing site traffic and implementing safety systems that are electrical.”
Over the past few years, Sullivan’s company has developed a full turnkey system. E1s are packed into 20-foot shipping containers to make them easy to transport and install. “We’re only using a fraction of the space inside of the container, but our customers like it containerized, so that’s what we offer,” Scullin says.
“The E1s have been field tested—thoroughly put through the wringer—in order to ensure a high degree of reliability and predictability of performance for our oil and gas customers.”
The technology is applicable wherever there is waste heat in the form of exhaust, says Scullin.
“There are certainly a lot of applications on vehicles and then there are a lot of applications in processing, as well, where you have waste heat. The E1 is our first turnkey product that we’re delivering to any industry and we’ve chosen the midstream compression industry because of the high value that waste heat has in that application. But our core technology, which is called the PowerModule, of which there are 32 inside the E1, is widely applicable on anything from cars to industrial facilities.”
The application in which Alphabet is seeing the most traction is midstream compression, at gathering-line stations that usually employ one-megawatt engines to compress natural gas, in Canada, in the Eagle Ford shale in Texas and in China.
The E1 installs in just a couple of hours and then doesn’t require any human interaction after that, so it’s virtually zero maintenance and operation-free, says Scullin.
By Lynda Harrison
CONTACT FOR MORE INFORMATION
Matt Scullin, Alphabet Energy Inc., Tel: 415-813-1201, Email: [email protected]
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