New thermophotovoltaic cell with no moving parts is more efficient than steam turbines

[Shawn Knight]

In brief: Researchers from MIT and the National Renewable Energy Laboratory (NREL) have successfully developed and demonstrated a thermophotovoltaic (TPV) cell capable of converting heat to electricity more efficiently than traditional steam turbines.

As MIT highlights, north of 90 percent of the world's electricity is generated from heat sources like natural gas, coal and concentrated solar energy. For the better part of a century, steam turbines have been used to convert heat from these sources into electricity.

On average, steam turbines are only able to reliably convert about 35 percent of a heat source into electricity. Even the most efficient heat engines ever made top out at around 60 percent efficiency. Worse yet, steam turbines rely on moving parts that must operate under a certain temperature threshold.

This new design aims to capture higher-energy photons from higher-temperature sources thanks to its use of higher-bandgap materials and multiple junctions. In testing between 1,900 degrees Celsius and 2,400 degrees Celsius, the new TPV cell maintained an efficiency of around 40 percent.

Earlier TPV cells average around 20 percent efficiency, with the most efficient ever hitting 32 percent.

"Thermophotovoltaic cells were the last key step toward demonstrating that thermal batteries are a viable concept," said Asegun Henry, the Robert N. Noyce Career Development Professor in MIT's Department of Mechanical Engineering and one of the researchers on the project. "This is an absolutely critical step on the path to proliferate renewable energy and get to a fully decarbonized grid."

There's still a lot of work to be done to reach that goal. The TPV cell used in the experiment measured about a square centimeter. According to Henry, they'll need to be scaled up to around 10,000 square feet (roughly a quarter of a football field) to be viable. Fortunately, he believes existing infrastructure used to make large-scale photovoltaic cells could be adapted for TPV manufacturing.

Image credit GE

Permalink to story.

https://www.techspot.com/news/94207-new-thermophotovoltaic-cell-no-moving-parts-more-efficient.html

 

[passwordistaco]

"fully decarbonized grid"

So, what will be their "decarbonized" heat source?

 

[Squid Surprise]

"fully decarbonized grid"

So, what will be their "decarbonized" heat source?

I'm gonna hazard: Nuclear or Solar?

 

[wiyosaya]

I'm gonna hazard: Nuclear or Solar?

IMO, solar would be more practical and is implied by "photo" in the name of this, however, there are lots of completely natural biological processes that might also be harvested given an efficient enough conversion process. If they were to separate the "thermo" part from the "photo" part, so that only heat is needed as an input instead of both heat and light, many natural sources might be used - such as volcanic sources like in Iceland.

 

[passwordistaco]

IMO, solar would be more practical and is implied by "photo" in the name of this, however, there are lots of completely natural biological processes that might also be harvested given an efficient enough conversion process. If they were to separate the "thermo" part from the "photo" part, so that only heat is needed as an input instead of both heat and light, many natural sources might be used - such as volcanic sources like in Iceland.

"between 1,900 degrees Celsius and 2,400 degrees Celsius"

Mirrors and lenses might get that in a small area from solar, but I don't think it would be practical for solar to apply that much heat to "10,000 square feet".

I'm reading "thermophoto" as radiant heat - photons in the IR spectrum.

Geothermal could do it in limited locations, if you had a stable enough environment with temps that high. The problem with volcanically active areas is that they tend to be volcanically active.

Nuclear would be the best option, but it's already the best option to run steam turbines and it's not doing us any good because we can't get reactors built.

 

[dualkelly]

"between 1,900 degrees Celsius and 2,400 degrees Celsius"

Mirrors and lenses might get that in a small area from solar, but I don't think it would be practical for solar to apply that much heat to "10,000 square feet".

I'm reading "thermophoto" as radiant heat - photons in the IR spectrum.

Geothermal could do it in limited locations, if you had a stable enough environment with temps that high. The problem with volcanically active areas is that they tend to be volcanically active.

Nuclear would be the best option, but it's already the best option to run steam turbines and it's not doing us any good because we can't get reactors built.

Nuclear powerplants heat water to produce steam to run turbines though.
This type of material would be best used in conjunction with the steam turbines. Perhapes as coating to the steam pipes so they can produce electricity from the already used heat once.

 

[Alfatawi Mendel]

Nuclear powerplants heat water to produce steam to run turbines though.
This type of material would be best used in conjunction with the steam turbines. Perhapes as coating to the steam pipes so they can produce electricity from the already used heat once.

Only problem with that, is steam cannot get anywhere near 1900 degrees.

 

[dualkelly]

Only problem with that, is steam cannot get anywhere near 1900 degrees.

Yeah not sure what the application is going to be for... steel melts at around 1425c.

 

[kiwigraeme]

Yeah not sure what the application is going to be for... steel melts at around 1425c.

I skim the article once - to really understand it would probably need to print out and read again and chew on. here's my 30 second skim

You find a non -carbon friendly energy source
You use that energy to do joule heating to make this device work TVP - it then produces electricity you store in for the thermal energy grid storage (TEGS) application1,17. TEGS is a low-cost, grid-scale energy storage technology that uses TPVs to convert heat to electricity above 2,000 °C.

Now I glanced at Joule Heating - but that was 3 second skim - anyway seems a std thing .
So don't think melting point of steel is relevant

To be pedantic temperature is just fast moving things - you put a lot together you gets a lot of heat ( ouch ) - ie one photon hitting you is unnoticeable ( not sure of 1 gamma ray )- but lots & lots concentrated can cut, burn you up .
Arc welders get super hot and they can be super small - and not very damaging
Anyway don't think temperature here is a problem - plasma in a plasma TV hits 1200 degrees Celsius

 

[B5S46M]

Only problem with that, is steam cannot get anywhere near 1900 degrees.

Only problem with that, is steam cannot get anywhere near 1900 degrees.

Tell me you've never taken a thermodynamics course without telling me you've never taken a thermodynamics course. Go look up a superheated steam stable and you'll see, even low pressure like 1 bar.

 

[scavengerspc]

*SIGH*

Another tech that I don't understand and will have to read up on.
I don't even know where to start.

 

[KenkaOni]

"between 1,900 degrees Celsius and 2,400 degrees Celsius"

Mirrors and lenses might get that in a small area from solar, but I don't think it would be practical for solar to apply that much heat to "10,000 square feet".

I'm reading "thermophoto" as radiant heat - photons in the IR spectrum.

Geothermal could do it in limited locations, if you had a stable enough environment with temps that high. The problem with volcanically active areas is that they tend to be volcanically active.

Nuclear would be the best option, but it's already the best option to run steam turbines and it's not doing us any good because we can't get reactors built.

This is a cell that will convert the solar panel's heat into electricity. It will not receive the solar light directly.

 

[quadibloc]

Energy storage is vital to making wind and solar power viable as energy sources. These cells are supposed to go inside some kind of thermal storage battery, so the primary energy source won't be providing heat at 1900 degrees Celsius.
That still doesn't quite answer the question of why you would need temperatures hot enough to melt steel inside an energy storage device (although the hotter the temperature, the higher the Carnot efficiency) but there isn't enough detail in the article to begin to work on that one.

 

[Roderek]

Try 90% efficient per the EPA. Also, the level of energy capture and boosting in powerplants makes them extremely efficient.

 

[Arbie]

Another tech that I don't understand and will have to read up on.

It can make pickups go faster. Does that raise the interest level?

;-)

 

[Theinsanegamer]

So this will be arriving shortly after fusion reactors and batteries with 10,000 recharge cycles. And it STILL wont work int he winter if you live above the 45th parallels.

 

[scavengerspc]

So this will be arriving shortly after fusion reactors and batteries with 10,000 recharge cycles. And it STILL wont work int he winter if you live above the 45th parallels.

And without even one reason a steam turbine would be outside in the cold.