Instead of solar roadways.... - Page 1
Forum section: electronics / general

author: SpectrHz
author_rank: Contributor
timestamp: June 21, 2014, 11:48:44 am
content: Since these solar roadways area bitunfeasible, I thought I would share something I have thought of in the past, thermoelectric roadways! Now, this is just conjecture, I have put little research into this, and it will undoubtedly have caveats making it not worthwhile, since TEGs are not that efficient... However I figured, what if in new road construction or repaving projects a network of thermoelectric generators were embedded into the asphalt or concrete, and as the roads were heated by the sun, the thermal energy could be used? You still have trusty old rock roads, and its relatively simple and would not compromise already laid out methodology of road construction.I have looked around a bit for this but have been unable to find anything that describes anything like this, and the idea was spawned after I thought of the curiosity rover, and how it utilizes an RTG, or radioisotope thermoelectric generator.I certainly do not expect this to work as i think, nor do I plan it to, I was just amused at the thought of roads with TEGs buried in them, and figured some might also be

author: Psi
author_rank: Super Contributor
timestamp: June 21, 2014, 12:17:39 pm
content: You'd need some sort of heatsink protruding down into the ground somewhat to give the peltier a good temperature difference to work from.

author: SeanB
author_rank: Super Contributor
timestamp: June 21, 2014, 03:06:50 pm
content: I was watching the building of the railroad to Tibet, and how they did a design that was floating on permafrost and used a passive radiator system using an ammonia refrigerant to cool the lower sections of the rail bed so that the permafrost would not melt with the conducted heat through the rail bed. They came up with a design that is both simple, easy to manufacture and maintain and yet which is an active heat pump which uses no external power source. Basically a thermal diode that dumps heat during the night to keep the bed cool during the day.

author: rollatorwieltje
author_rank: Unknown
timestamp: June 21, 2014, 04:13:48 pm
content: The office building I work at has a heated parking deck and ramp using (partially I think) geothermal energy. In the summer heat is pumped into the ground, in the winter heat is recovered again (afaik it's also connected to the climate control of the building).It required drilling a pipe almost 200 meters down into the ground and probably around 25 square meters of control equipment. Even with those additional costs it was still cheaper (in the long run of course) than to actually heat it with electricity or gas.Parking decks? Yes. Thousands of miles of road...Also this is the Netherlands, it doesn't really get really that cold here.If you really want to use thermoelectric generators, why not skip the conversion to electricity and use the heat directly? Just mix in some plutonium with the asphalt and it will stay warm

author: rob77
author_rank: Super Contributor
timestamp: June 21, 2014, 04:36:28 pm
content: Quote from: rollatorwieltje on June 21, 2014, 04:13:48 pmlet me refine your idea... just mix in some plutonium to the base of the road (the layers below the asphalt/tarmac).

author: Prime73
author_rank: Regular Contributor
timestamp: June 21, 2014, 04:38:50 pm
content: Quote from: rollatorwieltje on June 21, 2014, 04:13:48 pmNow that's something feasibleI think we should kickstart it

author: Artlav
author_rank: Frequent Contributor
timestamp: June 21, 2014, 05:57:14 pm
content: Hm, that might be a touch more practical than Solar Roadways.Don't forget that you have the ultimate heatsink - bedrock - just below the road.I have a summer house on Adriatic coast, half-embedded into the mountainside, and even be it +36*C outside, the back wall is always cold.So, use the rock as your cold side, tarmac as the hot side, and a layer of TEG sandwitched in-between.Sounds like a plan.Now, can someone do the math and pop it?Quote from: rob77 on June 21, 2014, 04:36:28 pmRadium, actually.And yes, that was seriously proposed in the 50s.

author: gildasd
author_rank: Frequent Contributor
timestamp: June 21, 2014, 06:48:10 pm
content: Quote from: Prime73 on June 21, 2014, 04:38:50 pmCareful with the choice of Isotope. Some of them will melt the car on top of it.

author: nctnico
author_rank: Super Contributor
timestamp: June 21, 2014, 09:50:27 pm
content: Quote from: rollatorwieltje on June 21, 2014, 04:13:48 pmThey actually heat the roads in Iceland using geothermic energy.

author: rob77
author_rank: Super Contributor
timestamp: June 21, 2014, 11:00:04 pm
content: Quote from: gildasd on June 21, 2014, 06:48:10 pmno worries.. we'll just make some public statements how safe it is and we'll make some fancy charts based on pseudo science.... and.... profit !!!

author: Wytnucls
author_rank: Super Contributor
timestamp: June 21, 2014, 11:07:21 pm
content: Quote from: Prime73 on June 21, 2014, 04:38:50 pmI think you meant 'fissible'

author: EEVblog
author_rank: Unknown
timestamp: June 21, 2014, 11:08:32 pm
content: Quote from: Prime73 on June 21, 2014, 04:38:50 pmAnd there is countless TONS of this stuff sitting unused. And in all those nukes, wow, you could recycle it and save the world from nuclear armageddon at the same time!This projects totally has legs!Forget Kickstarter, Indiegogo and flexible funding is the crowd funding choice of champion out-of-the-box stick-it-to-the-man projects!

author: rob77
author_rank: Super Contributor
timestamp: June 21, 2014, 11:20:45 pm
content: Quote from: EEVblog on June 21, 2014, 11:08:32 pmnot just saving the world from nuclear Armageddon... we could recycle all the waste from nuclear power plants ! that would be awesome !

author: gildasd
author_rank: Frequent Contributor
timestamp: June 21, 2014, 11:43:01 pm
content: Quote from: rob77 on June 21, 2014, 11:20:45 pmPlutonium silicosis - no problem - a rounding error at best! Can't have an omelet without shooting a few chicken.Let's crowd fund this thermonuclear bastard!

author: David Hess
author_rank: Super Contributor
timestamp: June 22, 2014, 09:46:49 pm
content: Quote from: gildasd on June 21, 2014, 06:48:10 pmChoose the right isotope and it will discourage traffic congestion just like minting coins out of radioactive waste will encourage spending and discourage hording:http://www.larryniven.net/stories/roentgen.shtml

author: dannyf
author_rank: Super Contributor
timestamp: June 22, 2014, 11:42:12 pm
content: QuoteTEG itself is all fine but why bury it in the roads? It can see it potentially on the roaf, or in the desert, or even on top of the roads. But why in the roads?Brainstorming is good. But this sounds like one of those poorly executed brainstorming ideas.

author: rob77
author_rank: Super Contributor
timestamp: June 23, 2014, 09:13:22 am
content: Quote from: dannyf on June 22, 2014, 11:42:12 pmTEG needs a temperature drop in order to workburying one onto the road would make senseblack tarmac/asphalt absorbs the sun energy while the substrate under the tarmac is colderin the desert you would have to bury the TEG's cold-side deeper and equip it with a black surface on top - solar panels would be better on deserts

author: Hypernova
author_rank: Unknown
timestamp: June 23, 2014, 03:54:04 pm
content: Using the ground as a heat sink is a pretty mature idea, I've seen builds at computer forums with guy laying down pipes in a ditch in his back yard to cool several computers at once.

author: rob77
author_rank: Super Contributor
timestamp: June 23, 2014, 04:57:43 pm
content: Quote from: Hypernova on June 23, 2014, 03:54:04 pmthat's a pretty common concept for heating new houses here - it's called "heat pump". basically it's a same thing like the refrigerator or air-conditioning machine - just operated in "reverse" for heating and eventually "forward" for cooling. the benefit is the ratio between the power consumption of the device and the amount of heat being pumped from the ground - it's somewhere in the 1:4 (or maybe 1:5) range.