Sterling engine+solar= neat powersource - EETimes article

Rxke · 2004-11-23 05:21:43

http://www.eetimes.com/at/news/showArti … 39]EETimes discusses a new old way to generate electricity, combining solar ovens and stirling engines, instead of the typical photovoltaic approach...
Fairly easy to scale, and claims it could rival classic ways of generating electricity.
Mars receives quite a bit less insolation, would this be practical?

John Creighton · 2004-11-23 13:44:06

It's an old idea. I believe they wanted to do this in Austria for quite some time. On mars just build a bigger dish. The big problem is the dust might make it hard to focus the light. Also since mars is cooler the engine may run more efficiently. Use the structure as a heat sink.

Rxke · 2004-11-23 15:11:58

Hm Yes. Stupid of me not having thought of the hazy atmosphere...

How hard would it be to service said contraption with the tools used in awell stocked metal shop? Less hard than servicing a cracked fuel-cell or photovoltaic solar panel, no?

RobS · 2004-11-26 12:44:33

I don't think photovoltaics need any servicing at all. These would need some. On the other hand, a Stirling solar system might be easier to build on Mars from scratch.

Another advantange: the Stirling will produce heat, and Mars bases will need it. When one includes the thermal energy the system produces, efficiency probably rises above fifty percent.

Dust storms will reduce the efficiency of any solar system to as little as 10% of optimum for as much as a third of the year, so any solar-dependent power system will have to store energy in the form of methane and oxygen or something else.

-- RobS

RobS · 2005-03-08 08:34:47

Here's a nifty new solar array technology:

http://www.spacedaily.com/news/solarcel … l-05b.html

"Light foil" is thinner than aluminum foil and is 15.2% efficient converting sunlight to electricity (not bad). The foil produces 1,440 watts per kilogram of mass. Thus a 100 kilowatt foil array would mass 69 kilograms in Earth orbit! On the Martian surface, multiply that by 2 for the weaker sunlight and multiply by pi (3.14) because the sun isn't overhead all the time; you get 433 kilograms. You probably want to double that mass to include cables, transformers, etc, and you want a bigger array because of dust storms (you'll still have to store power during global storms, though). This might be competitive with nuclear power, especially after crews are on Mars, so they can deploy the arrays and clean them.

-- RobS

MarsDog · 2005-10-30 03:47:54

More economical on Earth, but not Mars ?

http://www.stirlingenergy.com/breaking_news_photos.htm

noosfractal · 2005-10-30 04:09:00

More economical on Earth, but not Mars ?

I think in theory, still more economical on Mars, but in practice? In theory, the efficiency of Sterling/solar is 40% vs. 10-30% for solar cells. I saw one claim for 38% with solar cells if you used a concentrator - a lens-like dome over the solar cell.

But, if you bring the Sterling/solar from Earth, it is likely to be heavier than thin film solar. If it is more than twice as heavy, then you have a lower kW/kg

If you make it on Mars, it is likely to be way more complex than thin film solar to manufacture - you have to make a Sterling engine as well as the parabolic mirrors. So higher risk and maybe the additional manufacturing equipment (literally) outweighs the efficiency benefit. But maybe you'd only need to bring hyper-efficient Sterling engines from Earth and you could make the parabolic mirrors in-situ for a higher kW/kg. Worth considering.
.

MarsDog · 2005-10-31 00:54:55

Cost of land on Earth encourages more efficient design.
Ease of manufacture encourages solar panels on Mars.

noosfractal · 2005-10-31 03:05:23

Ease of manufacture encourages solar panels on Mars.

I think that's how it might work out, although solar panel manufacture on Mars isn't as easy as it is on the Moon - no free vacuum - in fact lots of dust to dim and scratch

Still, the Sterling engines are complex in comparison. Here is a report on the solar dishes that Sterling Energy is using (they were developed by Sandia) ...

http://www.energylan.sandia.gov/sunlab/ … r_dish.pdf

A 25 kW dish is 40 ft tall and weighs 7 tons (0.003 kW/kg - don't think we're going to be shipping those to Mars). Apparently they cost $150,000 each right now, but Sterling Energy is hoping to get that down to $50,000 a piece fairly quickly.
_

noosfractal · 2005-11-02 01:49:08

Here are some papers (brochures, really) describing some light-weight concentrators.

Ultra-light stretched Fresnel lens solar concentrator for space power applications (2003)
http://www.entechsolar.com/SpacePaper5.pdf

^ Made of 140 micron thick silcon rubber, stows flat, has pictures of it unfolding, adds 11% efficiency to give 27% efficiency overall, promises 0.5 kW/kg within 10 years.

Stretched-Lens Photovoltaic Concentrator Arrays for NASA's Moon/Mars Exploration Missions (2004)
http://www.entechsolar.com/IECEC04.pdf

^ Predicts 1.0 kW/kg by 2025
_

SpaceNut · 2019-12-11 07:21:48

more discusion on solar thermal, concentration and lenses

https://en.wikipedia.org/wiki/Solar-pow … ing_engine

https://rimstar.org/science_electronics … resnel.htm

SpaceNut · 2021-04-03 17:05:54

As I post this link to a 3d print units video I can see we have missed some active users for quite sometime now.

https://youtu.be/eZUteOLEKz8

Part 2
https://youtu.be/viEu5FYeKgI

https://hackaday.com/2021/03/31/spinnin … ng-engine/

tahanson43206 · 2021-04-03 19:13:20

For SpaceNut re #13

Thanks for bringing this topic back into view, and for the link to that (to me impressive) video of the 3D Printer project!

There was a Lot to that Project that was NOT 3D printed, but the critical moving parts (except for rod and bearings) seems to have been.

(th)

SpaceNut · 2021-04-03 19:19:31

Found the video when I was on the cell phone and now that the computer is back up will need to see it on a much larger screen to sse if I could make it or buy pieces that could be assembled into one.

The metal 3D printing as well.

I have solar that could be concentrated to the head and well water to do the cooling with all that is needed would be a generator head for power.

http://www.reprap-windturbine.com/index.php?id=16&L=1

https://www.athensjournals.gr/technolog … Clucas.pdf
3D Printed Stirling Engines for Education of Machine Design and Analysis

https://www.hilarispublisher.com/open-a … 000248.pdf

http://diystirlingengine.com/3d-stirling-engine-kit/

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#1 2004-11-23 05:21:43

Re: Sterling engine+solar= neat powersource - EETimes article

#2 2004-11-23 13:44:06

Re: Sterling engine+solar= neat powersource - EETimes article

#3 2004-11-23 15:11:58

Re: Sterling engine+solar= neat powersource - EETimes article

#4 2004-11-26 12:44:33

Re: Sterling engine+solar= neat powersource - EETimes article

#5 2005-03-08 08:34:47

Re: Sterling engine+solar= neat powersource - EETimes article

#6 2005-10-30 03:47:54

Re: Sterling engine+solar= neat powersource - EETimes article

#7 2005-10-30 04:09:00

Re: Sterling engine+solar= neat powersource - EETimes article

#8 2005-10-31 00:54:55

Re: Sterling engine+solar= neat powersource - EETimes article

#9 2005-10-31 03:05:23

Re: Sterling engine+solar= neat powersource - EETimes article

#10 2005-11-02 01:49:08

Re: Sterling engine+solar= neat powersource - EETimes article

#11 2019-12-11 07:21:48

Re: Sterling engine+solar= neat powersource - EETimes article

#12 2021-04-03 17:05:54

Re: Sterling engine+solar= neat powersource - EETimes article

#13 2021-04-03 19:13:20

Re: Sterling engine+solar= neat powersource - EETimes article

#14 2021-04-03 19:19:31

Re: Sterling engine+solar= neat powersource - EETimes article

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