Solar Thermal Fuel

[RobertM]

Scientists in Sweden have developed a specialised fluid, called a solar thermal fuel, that can store energy from the sun for well over a decade.

 

The fluid is actually a molecule in liquid form that scientists from Chalmers University of Technology, Sweden have been working on improving for over a year.

This molecule is composed of carbon, hydrogen and nitrogen, and when it is hit by sunlight, it does something unusual: the bonds between its atoms are rearranged and it turns into an energised new version of itself, called an isomer.

Like prey caught in a trap, energy from the sun is thus captured between the isomer's strong chemical bonds, and it stays there even when the molecule cools down to room temperature.

When the energy is needed - say at nighttime, or during winter - the fluid is simply drawn through a catalyst that returns the molecule to its original form, releasing energy in the form of heat.

https://www.sciencealert.com/scientists-create-liquid-fuel-that-can-store-the-sun-s-energy-for-up-to-18-years

 

 

[Nilao]

So how would this heat energy be used? It tales an awful lot of sunshine to convert a gallon of water to steam much less enough steam to run a generator. 

[InPhase]

9 minutes ago, Nilao said:

So how would this heat energy be used? It tales an awful lot of sunshine to convert a gallon of water to steam much less enough steam to run a generator. 

For heating. It could heat water or air. It won't release enough energy to make steam but if you use it to heat water and air instead of electricity, you can unburden the electric storage and use it for other things. The article was written in January of 2019. At that time, they claimed 250 watt-hours per kilogram of fluid. The catalyst causes a 63 degree C temperature rise.

[RobertM]

This fluid would flow through tubes exposed to sunlight, something like a solar water heater.  They suggest could be scaled down to be energized, stored, then used to power a single home.

Edited June 22, 2022 by RobertM

[NotMario]

240Wh/kg vs 12800Wh/kg for diesel. (diesel aka heating oil is common fuel for heat)

Such low energy density... useless as a storage for heat.
Maybe as an alternative to typical refrigerants - like for a sun powered heat pump?

Unfortunately, there's usually less sun available when heat is needed. No good for anywhere colder than temperate climate - at best.

More important question is the round trip efficiency of solar energy this way?

[RobertM]

3 hours ago, NotMario said:

Unfortunately, there's usually less sun available when heat is needed. No good for anywhere colder than temperate climate - at best.

 

This isomer can apparently be stored for a decade.

Edited June 23, 2022 by RobertM

[dochubert]

21 hours ago, RobertM said:

This isomer can apparently be stored for a decade.

So, to be useful, you would need a very large storage tank of this stuff.  You would energize it with plentiful summer solar, then sit on it until you need it in winter, then use it to warm up your house.

A very, very large tank I suspect.  Probably not feasible, but at least someone is thinking!

[RobertM]

5 hours ago, dochubert said:

You would energize it with plentiful summer solar, then sit on it until you need it in winter, then use it to warm up your house.

A very, very large tank I suspect.  Probably not feasible, but at least someone is thinking!

Solar panels don't only operate in the summertime. My guess is that you would energize in the daylight, and use the energy as needed, most often in the short term. I probably should research this technology, and see what is new. The article is three years old.

[RobertM]

Even now in 2022, it seems very experimental.

"After previously demonstrating how the energy can be extracted as heat, they have now succeeded in getting the system to produce electricity, by connecting it to a thermoelectric generator. "

“The generator is an ultra-thin chip that could be integrated into electronics such as headphones, smart watches and telephones. So far, we have only generated small amounts of electricity, but the new results show that the concept really works. It looks very promising,” says researcher Zhihang Wang from Chalmers University of Technology.  https://news.cision.com/chalmers/r/converting-solar-energy-to-electricity-on-demand,c3540525

[NotMario]

3 hours ago, RobertM said:

Solar panels don't only operate in the summertime. My guess is that you would energize in the daylight, and use the energy as needed, most often in the short term. I probably should research this technology, and see what is new. The article is three years old.

Clearly inexperienced with high latitudes... I get about 4 hours of twilight during the winter. I'm optimized more than most to gather this power, but i will still only get 2kWh/day at most. Winter requires 10kWh/day electric power at minimum, and an order of magnitude more in actual heating power.

This is one of the conundrums of green energy in the arctic. The winter is a doozey. We don't get enough sun, and wind cannot be relied on. We actually have to store an entire winter worth of heating in advance. Wood is the classic choice, diesel is the modern one - and even diesel requires about 1Kgal for a whole winter in my case.

Hopefully i've done my math correctly... That 1Kgal diesel equates to 40MWh of stored energy, requiring 167 tonnes of this substance at 100% efficiency. For one household. 😕

We have so far to go to crack this nut. But it's progress. I'm actually surprised it's only 167 tonnes. That's actually in the [very distant] realm of possibility if the volume is close to water... at >44Kgal.

[Sid Genetry Solar]

9 hours ago, NotMario said:

and wind cannot be relied on.

I'm in Ohio, and whenever I mention low sun-hours in the winter, people always say, "You need a wind turbine."

Problem is, I've lost track of the number of times I've been looking out the window on a "gloomy cloudy" winter day...and don't see the trees moving at all (i.e. no wind either).

[NotMario]

26 minutes ago, Sid Genetry Solar said:

I'm in Ohio, and whenever I mention low sun-hours in the winter, people always say, "You need a wind turbine."

Problem is, I've lost track of the number of times I've been looking out the window on a "gloomy cloudy" winter day...and don't see the trees moving at all (i.e. no wind either).

Exactly. Even in the most wind-ideal environments, the wind can still fail you. Combine that with insufficient solar, and you're back to good ol' fossil fuels. Boo!
I will say, one nice quirk is that cold weather has higher air density, so less wind can generate more power during the winter. It's just that little matter of when there's simply no wind...

Tidal and Hydroelectric may be our savior if households become efficient enough. Just the 100f+ temperature differentials are difficult to deal with efficiently.

The energy storage problem is a doozy. This thermal-fuel concept is great. Would be really cool if they can get the density way up - and even cooler if they could apply it to a substance with a "warm" melting point for efficient storage.

Oh, as an aside, we have considered jerry rigging an old turbine and put a dog run on it. The dogs like to spin in circles anyway (they want to go). Might as well turn that into power! lol

Edited June 24, 2022 by NotMario

[dochubert]

On 6/24/2022 at 11:34 AM, NotMario said:

we have considered jerry rigging an old turbine and put a dog run on it

If it works, use it!  Or a big hamster wheel for the dogs.

I've been looking into buiding a wood gasifier.  We already use a wood stove for heat, and I split my own firewood, leaving lots of bark and wood chips.  Use the gasifier to power a dc generator for direct battery charging on those gloomy winter days.  Problem is, I don't weld, so looking for someone to do the welding work.

[NotMario]

2 hours ago, dochubert said:

If it works, use it!  Or a big hamster wheel for the dogs.

Haha, well, it's got to be horizontal so as to allow them freedom. Aside from the technical hurdles (gear ratio being my main concern), there are some pragmatic issues. The main reason i would need this kind of generation is winter, and that is when the dogs work the hardest. They wont have the excess energy they have during the summer.

2 hours ago, dochubert said:

I've been looking into buiding a wood gasifier.  We already use a wood stove for heat, and I split my own firewood, leaving lots of bark and wood chips.  Use the gasifier to power a dc generator for direct battery charging on those gloomy winter days.  Problem is, I don't weld, so looking for someone to do the welding work.

I've heard about Those things. But for boilers instead...

What kind of generator would that work with? Propane? Pretty sure it's unsuitable for diesels because of no choke.
Cost of heating oil is over 5$/gal. I'm going to be burning a lot of wood this winter. Would be awesome to utilize that for generation.
What design are you trying to build? Got a schematic?

[dochubert]

7 hours ago, NotMario said:

What kind of generator would that work with? Propane?

Should work with propane or gasoline engines.  Any internal combustion engine, but not diesel.  I'm thinking of connecting a 48v windmill pma to a lawnmower motor, which will run on the gasifier output.  Just for charging my battery bank.

8 hours ago, NotMario said:

What design are you trying to build? Got a schematic?

There are several people on youtube with videos of working gasifiers.  Some more complicated than others.

I like this one best so far...

https://www.youtube.com/watch?v=a6e3CprVTi8

Then there is this one that requires no welding, supposedly...

https://www.youtube.com/watch?v=Bvl5XxVVjDM

Since I plan to use mine quite a lot, (not just to show off on a video), I probably will do a variation on the first one.  With a lot of use, tar will build up in the piping.  So more cleanout points and tar drain off collectors to add.  Also, the first guy used wood pellets.  Will work better and cleaner, but you have to buy them! (not happening!)  I want to burn my piles of bark and wood chips, getting more use out of the wood I split for my wood stove.

Collecting parts for it.  I have a drum and two old propane tanks saved so far.  Looking for something for the big filter box.

[InPhase]

15 minutes ago, dochubert said:

Should work with propane or gasoline engines.  Any internal combustion engine, but not diesel.  I'm thinking of connecting a 48v windmill pma to a lawnmower motor, which will run on the gasifier output.  Just for charging my battery bank.

There are several people on youtube with videos of working gasifiers.  Some more complicated than others.

I like this one best so far...

https://www.youtube.com/watch?v=a6e3CprVTi8

Then there is this one that requires no welding, supposedly...

https://www.youtube.com/watch?v=Bvl5XxVVjDM

Since I plan to use mine quite a lot, (not just to show off on a video), I probably will do a variation on the first one.  With a lot of use, tar will build up in the piping.  So more cleanout points and tar drain off collectors to add.  Also, the first guy used wood pellets.  Will work better and cleaner, but you have to buy them! (not happening!)  I want to burn my piles of bark and wood chips, getting more use out of the wood I split for my wood stove.

Collecting parts for it.  I have a drum and two old propane tanks saved so far.  Looking for something for the big filter box.

I've built several gasifiers and I can tell you that both of those gasifiers in the links suck. My first gasifier was like the one in the first link, a FEMA gasifier. It will work but it is very inefficient and very dirty. The tar it produces not only clogs an engine, but it is lost energy. The FEMA doesn't get hot enough to "crack" the tar and get the useable energy out. What you want is something along the lines of the restricted throat inverted V type gasifier. Checkout Flash001USA on YouTube. His gasifier is a good start. It can be improved. I based my second one on it but went heavier duty with stainless steel throat. Also look into "The Drizzler" gasifier. If I ever get the itch to start messing with gasifiers again, I might try that approach. But for now, my Flash gasifier works pretty good. It is almost entirely tar free and still works well after three years.

[dochubert]

5 hours ago, InPhase said:

my Flash gasifier works pretty good. It is almost entirely tar free and still works well after three years.

I looked at some of the video for the flash gasifier and it does look much better than the fema style from the other video.  I still need to watch all his contruction process videos but it;s looking like my best choice at this point.  Thanks for pointing me to it!

Now if I can just find someone local to do welding/fabrication without costing me a fortune....

[RobertM]

In the 1940's gasifiers were sold commercially and installed on cars. Some were remarkably clean burning, but they needed very dry wood to fuel them.

[InPhase]

1 hour ago, dochubert said:

I looked at some of the video for the flash gasifier and it does look much better than the fema style from the other video.  I still need to watch all his contruction process videos but it;s looking like my best choice at this point.  Thanks for pointing me to it!

Now if I can just find someone local to do welding/fabrication without costing me a fortune....

I'm sure you can buy a cheap Amazon wire feed welder, welding helmet and gloves for less than $300 and learn to weld. The ability to melt and stick pieces of metal together is well worth the effort and it becomes so handy that you will wonder how you ever did anything without it.

[TheButcher]

On 6/24/2022 at 1:55 PM, RobertM said:

"After previously demonstrating how the energy can be extracted as heat, they have now succeeded in getting the system to produce electricity, by connecting it to a thermoelectric generator. "

A TEG (think TEC or peltier device being driven the other way) is about the worst way to do this.  Yes it does work but pretty terribly.  If the objective was to produce electricity a gas cycle would be far more sensible (think refrigeration running in reverse).  This sort of thing is already in use using lakes as a heat source with the heat transfer straddling the thermocline in the lake / pond.

[dochubert]

On 6/27/2022 at 4:30 PM, RobertM said:

In the 1940's gasifiers were sold commercially

Wish I could jump in my time machine and zip back to 1940 and buy one!

[RobertM]

During the oil crisis of the 1980’s, the US Government produced and distributed plans for wood fuel gasifiers that could be made at home.

Although the technology is not new, Vendel has added his own improvements to create a very effective fuel product unit. On the first run, it successfully ran a 2.5 kW generator with a 1000 watt load for 2.5 hours on two 5-gallon buckets of wood scraps (the generator was a typical small gasoline utility generator. No special modifications were needed to make the generator run on wood fuel).