What 14% Efficiency Really Means
On its own, "14%" sounds modest. In thermoelectrics, at 550°C, it is the difference between a laboratory curiosity and a viable power source – and it is the starting point of the roadmap, not the destination.
Why 14% Is Not a Small Number
The figure to watch is not 14% on its own. It is 14% measured against where thermoelectrics have sat for fifty years.
Conversion efficiency is simply the share of the heat passing through a device that comes out as electricity. A rooftop solar panel turns roughly a fifth of the sunlight hitting it into power. A thermoelectric module does the same job with heat instead of light, and with no moving parts at all – a solid slab bolted to a hot surface, quietly producing direct current.
The catch, historically, was efficiency. For decades commercial thermoelectric devices converted under 6% of the heat they saw, and only below about 250°C. That was too little to justify the hardware anywhere except where nothing else would work at all – deep-space probes and remote sensors. Thermoelectrics were real, but commercially beside the point.
Crossing into double digits changes that calculation. At 14% module efficiency at 550°C, the same solid-state simplicity now recovers enough of a hot industrial exhaust to pay for itself in settings where it never could before. The jump from 6% to 14% is not a tweak. In an industry where commercial performance had barely moved since the 1970s, it is the step that moves the technology from interesting to investable.
The 14% figure is a module-level efficiency at a 550°C hot side, extrapolated from chip-level measurements by the US Army Research Laboratory and independently validated by the National Renewable Energy Laboratory. It describes today's first-generation devices.
Why a Like-for-Like Comparison Misleads
The 14% is not a higher score in the same game; it is a number from a different temperature regime.
This is one advantage, not two. It would be double-counting to say MicroPower is both more efficient and able to run hotter. The point is simpler: conventional commercial thermoelectrics are bismuth-telluride devices that stop working much above 250°C, where the best of them reach roughly 5–7%. MicroPower's PbTe/TAGS modules are built for the high-temperature band those devices cannot enter, and 14% is what they deliver there.
Comparing a 250°C part with a 550°C part on efficiency alone is not meaningful. They are made for different heat. The honest claim is not "we score higher in the same test" – it is "we operate, efficiently, in a temperature range conventional thermoelectrics do not reach."
The Alternatives for Waste-Heat Recovery
A turbine converts more heat than a thermoelectric module does. So why does 14% matter?
Thermoelectrics do not win a head-to-head efficiency race against a steam turbine, and MicroPower does not claim they do. The point is that turbines and Organic Rankine Cycle (ORC) systems only pay off at large scale, with water, working fluids, rotating machinery and continuous high-grade heat. A great deal of industrial waste heat does not come in that form. It is distributed, awkwardly shaped, intermittent in grade, or simply too small for a turbine to make sense. That heat is where solid-state conversion lives.
| Technology | Typical efficiency | Moving parts / fluid | Practical scale | Where it fits |
|---|---|---|---|---|
| Steam Rankine turbine | ~25–40% | Yes – turbine, boiler, water | Large (MW+) | Utility and large-process plants with abundant high-grade heat and water |
| Organic Rankine Cycle (ORC) | ~10–20% | Yes – expander, working fluid | Medium–large | Sustained medium-grade heat flows large enough to justify a fluid loop |
| Stirling engine | ~15–30% | Yes – pistons, seals | Small–medium | Niche; low power density (~0.5 W/cm²) and sealing maintenance limit adoption |
| Conventional thermoelectrics | ~3–7% | No | Any | Solid-state, but capped below ~250°C and historically too inefficient to justify at scale |
| MicroPower TEG | 14% at 550°C | No | Any – chip to many m² | High-temperature, distributed, retrofit and complex-geometry heat that turbines and ORC cannot serve economically |
So is 14% a meaningful improvement? On the efficiency axis alone, no – a turbine beats it. On the frontier that actually matters for this hardware – efficiency combined with no moving parts, no water, conformity to any heat-source shape, true retrofit, and operation above 250°C – reaching 14% is what pulls solid-state conversion across the line from unviable to viable. That is the real improvement: not a higher number than everything else, but a viable number in an envelope nothing else can occupy.
Efficiency ranges for turbines, ORC and Stirling systems are approximate and vary widely with source temperature and scale; they are shown to frame the trade-off, not as precise specifications.
Where the Technology Is Going
14% is the first generation. The technical plan targets 25% and beyond.
Solid gold bar is today's validated first-generation figure. The two lighter bars are development targets from MicroPower's technical plans, not current product performance.
The levers that get there
The path from 14% toward 25% and above is not speculative physics. It runs through four engineering levers the company has already characterised:
Chip reconfiguration. Adjusting leg dimensions and geometry to extract more watts from the same temperature difference.
Base-material development. Refining the PbTe/TAGS ingots to lift efficiency and widen the usable temperature range.
Contact and interface structures. Reducing losses at the joints where heat and current enter and leave the chip.
The energy-sorting barrier layer. A patented chip architecture shown to raise power density by up to 1.8× on PbTe at chip level. It is part of the post-funding production roadmap, not a feature of current modules. Power density rises alongside efficiency on the same plan: from 11 W/cm² capability today toward a 20 W/cm² target, meaning less hardware for every watt produced.
These are described in more depth on the How It Works and Materials & Manufacturing pages.
What the roadmap depends on
We are deliberate about the distinction between what is proven and what is planned. The 14% module figure is today's validated reality. The 25% target and the generations beyond it are grounded targets, set out in the company's investment and technical documents and resting on physics and intellectual property that already exist.
What stands between the two is not a scientific unknown. It is execution: assembling the engineering team to do the development work, and the capital to fund it. MicroPower has the materials platform, the patents and two decades of high-temperature thermoelectric experience. Realising the roadmap is a matter of resourcing the work, not discovering whether it can be done.
That is the honest shape of the opportunity: a validated starting point, a mapped path to several times the addressable value, and a clear statement of what it takes to walk it.
What Higher Efficiency Unlocks
Efficiency is not a vanity metric. Each step up opens whole categories of application that were simply uneconomic before.
At 6%, thermoelectrics were a niche for places nothing else could reach. At 14% they become a credible recovery technology for mainstream industrial heat. At 25% and beyond, the picture opens again – and because the same platform spans multiple materials, the gains compound across every temperature bracket at once.
Whole categories of application open up
Each efficiency step moves more of the world's heat into reach: industrial waste heat, behind-the-meter and datacentre power, thermal-storage discharge, bioenergy, off-grid and portable power. Applications that made no economic sense at 6% become viable at 14% – and the list lengthens at 25%.
Efficiency across the temperature spectrum
The platform is material-agnostic. BiTe covers the low-temperature tail and cooling; PbTe/TAGS covers the mid-temperature power band (~300–600°C); HgCdTe and InSb reach into the cryogenic. Lifting efficiency within each material system unlocks higher performance in a different temperature bracket – so progress opens several markets at once, not just one.
Less hardware per watt
Efficiency and power density climb together. Reaching the 20 W/cm² target means fewer modules for the same output – lower installed cost, a smaller footprint, and a stronger economic case on every project.
See how this plays out per sector on the Power Generation and Industrial Waste Heat pages.
The Starting Point, Not the Ceiling
14% today, a mapped path to 25% and beyond, in a high-temperature lane with almost no commercial competition. Explore the science behind it, or the markets it opens.
How It Works Explore Applications