Silent thermoelectric Generator?

[StuM]

Originally Posted by redneckrob

Ymake sense. They've sold these things for years to put on top of home wood stoves, for example, so it's nothing new.

But you generally don't have to plumb in a seawater line for your wood stove

[Dsanduril]

Man, I wish someone would come up with something like this - small power, small footprint, easily available fuel - with a decent efficiency number. Still TANSTAAFL.

Another little nugget hidden away in the specs:

less than 30dB(A) at 7mt, ZEUS200 permits to smoothly sleep while it is running

That puts it at something like 45-50dB at 1 meter, which is a much more interesting number to me if I’m going to be sleeping next to it. Being fair, the 7m distance is an ISO standard, but it is geared toward measuring how annoyed people on the next boat over will be if your generator is running, not how loud it will be for you.

[Adelie]

Originally Posted by Pdemajo

Hi All,

An Italian company recently produced what they refer to as an ECO Friendly Thermoelectric Silent Generator.

https://www.mobiltech.it/zeus200-en/

They promise 200W, with hardly any fuel, hardly any noise, and a lot of other good things...
Obviously the output is low, but if its silent and doesn't consume one could leave it o for extended periods...

Has anyone used it, or understand the difference from a normal genset? Any thoughts on it?
thank you..

It will not be nearly as efficient with the fuel as an IC engine. That is an ICE will provide 5-10x as many kW-hr as the TE generator.

The only upside and the reason NASA and other space-probe launching agencies use them is they are dirt simple and require no maintenance. There is a very different cost-benefit analysis for space probes than for cruisers.

[StuM]

Originally Posted by Adelie

The only upside and the reason NASA and other space-probe launching agencies use them is they are dirt simple and require no maintenance.

and have no "moving parts"

[Adelie]

NASA et al is indifferent to whether there are moving parts, it's the no maintenance for something they will never have access to again that is important.

In the case of thermo-electric no maintenance is related to no moving parts.

But there are things like thermionic generation that arguably have moving parts (a flowing gas) that are no-maintenance.

An then there are Stirling engines that definitely have moving parts but the mean time between breakdowns is long enough that NASA would consider them for use as they are effectively no-maintenance for a certain time horizon.

[Jammer]

Originally Posted by Pdemajo

Thank you Jammer....do you think it could be dangerous to have a device such as this on board?

I don't think there's anything dangerous about the electrical side of it.


Whether the burner side of it is safe depends on how well it is designed. Most such systems are carefully engineered and are safe, but not all. It's fire that's inside your boat. Who knows. Lots of heating and generating equipment poses a fire risk.

[NSboatman]

What ever happened to those whisper gens anyway? They seemed like a really good piece of engineering at the time.

Too expensive/too complex? Anyone here ever run one? 5kw of steady heat and 80a continuous dc output @ 12v with only a ‘whisper’ seems pretty ideal!

...full disclosure, I bought one some years ago (a running take out allegedly) and have it in the shed, along with a bucket of parts- but haven’t found the time to try and start it up yet, let alone install it!

...could be a box of rusty bits by now for all I know!

[Jim Cate]

NASA et al is indifferent to whether there are moving parts, it's the no maintenance for something they will never have access to again that is important.

Do NASA or other space operators actually use fuel based generators in spacecraft? I would have thought fuel supply would rule that out.

My (now obsolete) knowledge of such things was that they used isotope decay heat sources for such devices. At least one such used Pu-238 as a heat source and IIRC thermopiles as generators rather than Peltier devices.

Pu-238 has a half life just under 90 years, so fuel replenishment is not an issue. It is, however, a rather dangerous material (much more so than the "deadly Plutonium 239" so beloved by the press) and kinda hazardous to have around the house or boat. Might be a bit too expensive for yottie use, too.

But handy to have around...

Jim

[newhaul]

Originally Posted by Jim Cate

Do NASA or other space operators actually use fuel based generators in spacecraft? I would have thought fuel supply would rule that out.

My (now obsolete) knowledge of such things was that they used isotope decay heat sources for such devices. At least one such used Pu-238 as a heat source and IIRC thermopiles as generators rather than Peltier devices.

Pu-238 has a half life just under 90 years, so fuel replenishment is not an issue. It is, however, a rather dangerous material (much more so than the "deadly Plutonium 239" so beloved by the press) and kinda hazardous to have around the house or boat. Might be a bit too expensive for yottie use, too.

But handy to have around...

Jim

Nope they are still using Pu238 and thermal piles on satellites

[Adelie]

Originally Posted by Jim Cate

Do NASA or other space operators actually use fuel based generators in spacecraft? I would have thought fuel supply would rule that out.

My (now obsolete) knowledge of such things was that they used isotope decay heat sources for such devices. At least one such used Pu-238 as a heat source and IIRC thermopiles as generators rather than Peltier devices.

Pu-238 has a half life just under 90 years, so fuel replenishment is not an issue. It is, however, a rather dangerous material (much more so than the "deadly Plutonium 239" so beloved by the press) and kinda hazardous to have around the house or boat. Might be a bit too expensive for yottie use, too.

But handy to have around...

Jim

Using any kind of chemical fuel on a space craft doesn't work except in the very short term.

To the best of my knowledge the closest NASA came to chemically fueled generators was the fuel cells that were aboard the Gemini & Apollo missions and the shuttle. Mercury relied on batteries.

Anything that went interplanetary relied on solar cells or radio isotope generators long term with batteries for short and medium term storage.

With radio isotope there is a very high energy to weight ratio over the long term which is why space folks like them.

The question then is how to convert the heat energy into electricity. Thermocouples were a reasonably well established technology and had sufficiently long life times when planetary missions started so that's what was used.

There are other conversion technologies that might work if they ever mature such as Thermionics and Stirling.

Thermionics has a working gas/fluid but otherwise no moving parts. I believe the efficiency is better than thermocouples but there are various problems that haven't been worked out such that it can be lighter per Whr. I haven't looked at it recently so I don't know what the exact problems are.
The space folks are interested in Stirling because it can be built with one moving part, the piston which cycles back and forth in a cylinder. To make that work there is a magnet in the piston and a coil around the cylinder which then generates the electricity. Efficiency is much better than thermocouples. The development price tag is what's keeping it from gaining traction.

Other conversion methods such as turbines and various other external heat source engines have so many closely machined parts needing lubrication and maintenance that they are non-starters for space use.

Going back to the OP's question. Thermocouples aren't a economical electrical generation source for terrestrial applications except a very few special applications, they just aren't very efficient.

[StuM]

Originally Posted by Jim Cat3274126

My (now obsolete) knowledge of such things was that they used isotope decay heat sources for such devices. At least one such used Pu-238 as a heat source and IIRC thermopiles as generators rather than Peltier devices.

Thermopiles are essentially compound "Peltier devices".

Seebeck/Peltier effects are two sides of the same coin. One is heat differential generated by electricity the other is electricity generated by heat differential but it's all the same physics in reality.

https://en.wikipedia.org/wiki/Radioi...tric_generator
A radioisotope thermoelectric generator (RTG, RITEG) is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect. This type of generator has no moving parts.

And yes,NASA did and do use isotope decay as the heat source. (as per my post #2)
Voyager 1 has three radioisotope thermoelectric generators (RTGs) mounted on a boom. Each MHW-RTG contains 24 pressed plutonium-238 oxide spheres.[25] The RTGs generated about 470 W of electric power at the time of launch, with the remainder being dissipated as waste heat.[26] The power output of the RTGs declines over time due to the 87.7-year half-life of the fuel and degradation of the thermocouples, but the craft's RTGs will continue to support some of its operations until 2025.[

[HopCar]

I built one of those for a junior high science fair. I managed to generate enough electricity to make a flash light bulb glow. I used a propane torch as a heat source. I’m sure theirs has to be more efficient than mine was.

[Pete7]

Suddenly a little Honda generator looks remarkably efficient. From their website:

ZEUS200 thermoelectric generator is installed in fixed mode inside the boat, without occupying any useful space within the living area.

Installation can also be carried out on small boats. Find the ideal position for ZEUS200 together with your authorized dealer.

It weighs 36 kgs so won't be finding a place on my small yacht. The Efoy weighs 7kg by comparison for 960Wh a day.

Pete