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Use of Asphalt Paved Surfaces For Solar Heat

timothy posted more than 6 years ago | from the but-it's-a-gross-heat dept.

Power 110

vg30e writes "It seems that a company in the Netherlands has found a way to use asphalt paved surfaces as solar heat collectors. Flexible tubes under the surface of the road collect heat from asphalt pavement using water as the working liquid. The heated water is stored underground for later use in defrosting the road, or heating buildings. With all the miles of highway in the continental US, this might be a viable way of collecting massive amounts of thermal energy."

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Old idea from Universty of Chicago (3, Informative)

2.7182 (819680) | more than 6 years ago | (#21877640)

Physics professor Roland Winston, proposed this 25 years ago.

Re:Old idea from Universty of Chicago (3, Insightful)

madsenj37 (612413) | more than 6 years ago | (#21877732)

The idea is one thing, the implementation another. He may have been a visionary, but the buck stops there.

Re:Old idea from Universty of Chicago (0)

Anonymous Coward | more than 6 years ago | (#21878350)

One mod's "interesting" is another man's gibberish, apparently.

Re:Old idea from Universty of Chicago (0)

Anonymous Coward | more than 6 years ago | (#21878378)

No no! If this first guy put the idea on public record, then these later guys can't patent it. Even if it was never implemented.

Re:Old idea from Universty of Chicago (1)

Entropius (188861) | more than 6 years ago | (#21878930)

So? The later guys can still *do* it.

There's no patent on the screwdriver, but people still make money selling screwdrivers.

Re:Old idea from Universty of Chicago (2, Insightful)

lpangelrob (714473) | more than 6 years ago | (#21878410)

It's an interesting idea. There are a lot of factors to weigh in, and the primary one is cost - odds are pretty good that doubling the initial cost of construction of a freeway this way won't result in nearly that much savings on maintenance (even accounting for less resurfacing, potholes, and salt spraying) down the line.

Then there's the fact that having a pump fail anytime during the cold season would almost certainly result in the destruction of the surface, unless there's some sort of way to engineer around this sort of failure.

Anyways, it's mentioned in the article that this isn't a new idea, and in fact warming a surface from below is commercialized on a smaller scale, only using electric power, and with surfaces about the size of driveways. ([1] [allwarm.com] )

On highways and byways, this particular idea would work well on a larger scale only if there were enough other users to offset the initial costs of building the system, and if that engineering problem could be fixed.

Re:Old idea from Universty of Chicago (1)

afxgrin (208686) | more than 6 years ago | (#21878876)

We need a cheap way to modify asphalt so that it can be used to generate electricity. It really needs to be done chemically. Then any road repairs or new roads can be done using the new asphalt which would have some type of wire mesh laid down that could convert the collected solar energy. Even if it's inefficient, it doesn't matter, there's so much road out there it would make a difference. Again, a key requirement would be making the cost of said "electro-asphalt" low enough that it would attract buyers compared to standard asphalt. Think of parking lots at malls, paved with this shit, collecting power for the mall reducing their overall operating cost. Highways, urban streets, it's everywhere - if we're going to pave over the world, we might as well make the most of the land we're paving, and use it collect electricity.

Pipes and water just sound like a bad idea in general. Sounds like high maintenance costs, not necessarily suitable for all weather environments, high installation cost, specialized labour and more unions, ... it just sounds impractical.

Re:Old idea from Universty of Chicago (2, Funny)

bcattwoo (737354) | more than 6 years ago | (#21881788)

Pipes and water just sound like a bad idea in general. Sounds like high maintenance costs, not necessarily suitable for all weather environments, high installation cost, specialized labour and more unions, ... it just sounds impractical.
Right, certainly not as practical as your apparently low maintenance, all weather, low cost, monkey installed, made from unicorn horns electrical asphalt.

Re:Old idea from Universty of Chicago (1)

afxgrin (208686) | more than 6 years ago | (#21882162)

Well repairing leaky pipes is a serious pain in the ass. Especially when you pull one damaged section out and it leads to breaking another pipe joint that's also buried. I'd much rather replace wiring than pipes. Again - the whole idea I mentioned depends heavily on the magical unicorn horn asphalt. If that can be developed, I think it'd certainly be more practical. There has to be some chemist out there who would lose sleep trying to make it work.

Re:Old idea from Universty of Chicago (1)

SQLGuru (980662) | more than 6 years ago | (#21884230)

How about this:
I'm sure each of you have felt the "bounce" of a big truck passing you by....why not create some sort of mechanical compression layer that absorbs the effect of cars going over the road section.....it then converts this into a small amount of electricity.....probably most effective on highways and heavily travelled city streets.

And, on top of that, it would still allow for some thermal collection since it would be a different layer.

Layne

Using bouncing energy usually backwards (2, Insightful)

arete (170676) | more than 6 years ago | (#21885132)

As a rule, this idea is usually backwards. In order to gather significant power from this, you're basically increasing the amount of energy the vehicles expend - because for this to work, you have to keep the pavement bouncy enough to generate the power. (Put another way, the vehicle is most efficient if the pavement is very flat and very rigid)

So you're usually sucking energy FROM poorly maintained oil driven vehicles and putting it TO a grid that at least hypothetically could be powered by nuclear or wind at much lower cost and environmental impact.

The major kinds of places this sort of technique is useful: a) because the main problem is that you NEED to be far away and disconnected from the grid... b) where the bounce energy you're trying to capture is orders of magnitude smaller than the actual bouncing action c) where the initial energy is biomechanical, which is both pretty efficient and otherwise hard to optimize further.

Using this to power small road sensors that didn't need to be wired up would be fine. Using it to power an efficient laptop would be fine - if you're actively looking for a way to easily get more exercise. Using it to power a watch is pretty much ideal, which is why this has been around a long time.

Re:Using bouncing energy usually backwards (1)

IdeaMan (216340) | more than 6 years ago | (#21887136)

So combine A and inverse of B:
Use the heat differential to power a Stirling cycle heat engine that gives energy to the road vehicles.
Benefits:
#1: Decreased stopping distance: Force sensors in the roadway can detect when the vehicle is decelerating, and simply multiply that force * 3.
#2: Decreased emissions. Heat->electricity means no emissions.
#3: Synchronizes vehicle speeds. The system can be set up to only provide power to vehicles that are moving the proper speed.
And no, that wouldn't necessarily be the same speed for all lanes or conditions.

Re:Old idea from Universty of Chicago (1)

afxgrin (208686) | more than 6 years ago | (#21885474)

yeah I was thinking of a way to utilize that energy as well. Maybe with two to three layers of slightly different asphalt. I guess I should do some more research on asphalt. Maybe quartz chunks could be mixed into the centre layer, and can create some sort of piezoelectric charge. That probably won't work because it would be highly dependent on the crystal structure (so if it's ground into chunks, that doesn't leave much of a structure... ), but it's an idea.

Another idea could be mixing iron into the top and bottom layers of asphalt, with a non-ferrous centre layer. When the top layer has pressure applied to it, a current maybe induced. Obviously this would introduce issues of oxides forming, so maybe another metal that's available in large quantities and on the cheap could be used. In addition the conductivity of the asphalt with an iron mix would probably be highly questionable.

heh I guess my reading for the night will be pressure sensors, asphalt, quartz, and random chemistry shit.

Re:Old idea from Universty of Chicago (1)

Hoi Polloi (522990) | more than 6 years ago | (#21882700)

Maybe instead of purpose built pipes you could use semi-porous asphalt or concrete (which already exist) wrapped in a layer of sealed asphalt. Then the small channels in the asphalt act as the pipes. There'd be no pipes to maintain or replace. Force water in from one side and pull it from the other. Just don't try it in freezing temperatures.

Already in place. (1)

ReverendLoki (663861) | more than 6 years ago | (#21883496)

When our business laid down a new concrete parking slab for a dock building, we used a pigmented concrete and did this very same thing. Loops of tubes laid down before the pouring, and now we can run cold city water through it in the summer to heat it up before it hits the boilers, and run excess warm water through them to de-ice it in the winter. It also helps that we're in a business that uses a lot of steam and hot water.

This could help safety also... (2, Interesting)

LWolenczak (10527) | more than 6 years ago | (#21877648)

This could help reduce the overall temperature of blacktop services... which have this side effect in very hot summers of melting.

Re:This could help safety also... (1, Insightful)

Anonymous Coward | more than 6 years ago | (#21877852)

The problem we have isn't an availability of energy. We have more energy than we know what to do with. The problem is an economical way of converting it to the desired form, and moving it to the places where it is needed. Oh, and do that without ruining our planet, hopefully.
That said, this is another solution in search of a problem; I can't imagine that it would be even remotely economical to embed tubes in asphalt during construction. Then, remember how roads get cracks in them? That's gonna tear your tubes apart, or at least leave them exposed enough that something else (a passing semi or snowplow) will do the job. Then you've got leaks. Now that's not too bad; you're using water, so it's not a big deal if you leak some. But over time you're going to have to repair the tubes, probably before the roads need to be repaved. And those leaks could, in some cases, lead to destruction of the roads; if you've leaked water into all the tiny little crevices inside the blacktop, and then the temperature drops below freezing, PRESTO! you have a road with tons of little cracks in it. And next time it freezes, there will be tons of larger cracks.
I have a feeling that the numerous drawbacks to this approach will negate the benefits one might get. Bonus points for trying to attack the problem from a relatively unexplored perspective, but there are at least a hundred other alternatives that are probably better than this. I'd be willing to bet that a system designed specifically for focusing the sun's energy and capturing it in water will be both cheaper and more efficient than this chimera.

Just don't let the roads freeze. (1)

Tangent128 (1112197) | more than 6 years ago | (#21878296)

The article mentions that the system can be used as a de-icer, meaning it actually does work on the "moving [energy] to the places where it is needed" problem.

That said, using the roads as solar collectors isn't that bad an idea in general. Roads cover a significant amount of square footage, which is left mostly vacant most of the time (outside of cities). May as well use that space for something the rest of the time.

Re:Just don't let the roads freeze. (1)

sumdumass (711423) | more than 6 years ago | (#21879314)

What do you use as a qualifier for GOOD as in a good idea?

It sounds like an interesting idea to me that should be explored but if it turns out to double or tipples the costs of the road, there there might be a problem. We are having trouble paying to maintain them now. And as for generating energy, if it is three times as expensive as traditional methods, then it would be waisting money again. And by energy, I'm not just talking about electricity or heating large buildings with hot water or something like that. I'm also talking about melting snow and ice and so on.

I would say that a cost analysis needs to happen first in order for it to be a good idea.

Re:Just don't let the roads freeze. (1)

hedwards (940851) | more than 6 years ago | (#21880732)

We don't have trouble paying for road maintenance, we choose not to. Totally different thing. Locally we have a narcissist that gets his jollies by filing anti tax initiatives to see his name and picture in the papers. Then you've got the portion of the populace that doesn't think twice about supporting a bloated runaway military budget, but can't stand the idea of his money going to fund things for the common good.

It isn't an inability to pay, or even a difficult time finding the money, it's that people would rather use the money on frivolous things than actually solving problems. Note I'm not saying that the military should be separated from all its funding, I'm suggesting that it should be budgeted for in the main budget, and that military operations should take into account funding when we're thinking about starting something halfway around the world.

One thing which has been done in some areas is to just contract out the maintenence to a private outfit, and hold them responsible if things don't work right. It does work, as long as the budget is realistic and there are actual penalties for failure or fraud.

Re:Just don't let the roads freeze. (1)

sumdumass (711423) | more than 6 years ago | (#21882486)

Choice or not, we wait until bridges fall down before we get worried about it. There is actually enough taxes collected from the Use taxes associated with roads. The Gas and Diesel taxes, the DOT taxes on tires and so on. The problem is that the money goes to things other then roads. So your right, it is more of a choice then an ability but when you have people robbing the till for social programs and stuff that normal citizens should be providing for themselves, we have trouble maintaining the roads. It is inherent in our political structure. Someone always thinks they have a better use for the funds and some people will always want to throw money at programs that don't work.

As for funding wars in main budgets, That is a very very bad Idea. You don't want to institute a normality with war. You always want it to be a separate venture that is never ingrained in the core of a countries budget and economy. Sure, you think we would be less likely to goto war, but what would happen is that some enterprising politician would see that we didn't spend as much as we budgeted for a year of war and then either cut the budget leaving service member out to die or they would see the surplus as a cue to start another war. The only way to budget a war is to keep it separate from a normal budget, force members of the government to openly debate funding it and keep the funding necessary to keep troops relatively safe when asking them to put their lives on the line. It sounds like you might be happy if we didn't have the war or military but the fact of the matter is, we would be so far worse off it isn't funny. There would be problems from half the economy collapsing that cares for and supplies the military to rampant unemployment when several million jobs are displaced and we are already having problems finding enough work for everyone.

Budget the normal military in the regular budget. Allow some secrecy for weapons and weapons systems development but keep funding for wars completely separate. Force the constant debate and make then know that when choosing to enter a war, they will have to confront people to fund it. IF they aren't willing to do that, they probably aren't willing to take us to war so easily. You wouldn't want a rider on some crime bill increasing the war budget to allow the military to invade some other country. It needs to be separate.

Re:Just don't let the roads freeze. (0)

Anonymous Coward | more than 6 years ago | (#21883076)

Bombs and bullets are sexy and make politicians feel tough and important. Pavement and public health are boring, complicated and make politicians feel dumb and invisible.

Re:Just don't let the roads freeze. (1)

budgenator (254554) | more than 6 years ago | (#21881036)

We just did a rebuild of a strech of our expressway, first they laid down rebar, reinforcing bars. I don't see where installing some plastic tubing in with the rebar would make a huge difference in costs. Did you know that when they build the Hoover dam, they laid in pipes to cool the concrete as it cured [wikipedia.org] , if they didn't it would be hot enough to burn you still today. Next they laid down concrete, not the ususal concrete but a drier concrete that was spread over the rebar with a machine that looked like an asphalt spreader and was then compacter with rollers, after that had cured a while a veneer of asphalt was laid on top. The biggest expense would come from either connecting the section to a manifold or the actual wells that the manifold connect to the aquifers with. Life of the of the roadbed would be greatly incresed because thermal expansion and contract would be reduced and that is a major killer of our roads.

Re:Just don't let the roads freeze. (1)

sumdumass (711423) | more than 6 years ago | (#21882692)

A couple of things, first, it isn't necessary to use concrete for roads in every place. In places where there is extreme heat or cold, concrete works best, in places with already firm bases (the types of dirt used for foundations) for the roads, moderate temperatures, Asphalt works great. So while in the places with concrete already, it probably wouldn't be too much more to put the pipes in unless your talking about destroying repairable roads to redo them with piping. Then it just doesn't make sense at all. But changing from an asphalt road to a concrete road signifies a major increase in costs for some areas. Not to mention that Asphalt has been used in places where concrete would probably work better because there isn't a local source of concrete and is would need to be trucked in.

As for the Hoover dam, times are different now. When the Hoover dam was built, wages were a lot cheaper, people worked longer hours and so on. The costs associated with the Hoover dam was enormous compared to other damns of similar scope of the time too. Most of the workers on the dam were attempting to escape the depression and could be had dirt cheap. That was one of the reasons for building the dam, to employ people. It was cheaper to put up housing and keep them on site in company towns then it was to pay a good wage and let them travel back and forth. We just couldn't do something like that today. I saw a thing a while ago with prevailing wage and scale and all, to do the Hoover dam in the with period methods, in the 1990's, it would cost trillions where the inflation value (cost adjusted for inflation) costs of the dam only reached billions.

It is an impressive feat of engineering but the times something like that could be built are gone. It could be done still but the costs make it somewhat unreachable. Instead, today they would do it differently with cheaper materials, automation to some extent and probable scale the size back quite a bit. The question becomes do we have the money to spend that someone wouldn't think would or could be better spent somewhere else.

Lets see some cost analysis of fitting new roads with and reworking repaired roads before jumping on the You need to do it band wagon. I have seen traffic accident where a vehicle caught fire and burnt the road surface down to the base. This is something else that needs to be looked at.

Re:This could help safety also... (1)

chawly (750383) | more than 6 years ago | (#21882008)

To say nothing of the effects of very hot winters

Cement (1)

russ1337 (938915) | more than 6 years ago | (#21877716)

Here in Texas, most of the roads are cement*, but I guess you could apply the same principle. Why would you store heat in Texas, it's here in abundance. Come take some.

*Here, they use asphalt to fill in potholes.

Re:Cement (0, Troll)

dltaylor (7510) | more than 6 years ago | (#21877882)

It snows in El Paso in January/February, and in Amarillo more than that. Texas is a hell of a lot bigger than Austin, or whatever small part of it you're familiar with. Even in the winter, the road surface is usually enough warmer than the snow-covered ground to provide some useful energy.

There's another source of heat in addition to the solar input. Passing vehicles emit heat from the exhaust (including the catalytic converters) and there's heat built up from the mechanical stresses, 'specially the "big rigs".

Re:Cement (-1, Flamebait)

Anonymous Coward | more than 6 years ago | (#21878904)

Have you been in El Paso in the summer dumbass? Even though it snows in the winter, it gets very hot in the summer. Oh, and for solid evidence you're a dumbass. The heating of the road comes from flexing of the tires, not from exhaust. You're a retard; you didn't even read the post you tried to slam.

Re:Cement (0, Offtopic)

russ1337 (938915) | more than 6 years ago | (#21879078)

It's replies like yours (Parent), why I filter off ACs. Get an account and post with it.

(You just happened to catch me reading the GP and I thought, oh, someone replied. )

Re:Cement (1)

jojo1835 (470854) | more than 6 years ago | (#21878404)

Funny, here in Chicago they do the opposite. Use cement to patch a hole in an asphalt road.

Tim

Re:Cement (-1, Troll)

Anonymous Coward | more than 6 years ago | (#21878784)

Good point about Chicago. Much of the northern US does that. It's because the dissimilar materials expand and contract at a different rate which creates openings that allow water to enter. Once water enters a crack in winter, you will have damage as it freezes and thaws. This creates a lot more work thus creating jobs to repair the roads. It also damages cars which creates jobs to do repairs and to build new cars. You see the Democrats in those big cities in the northeast fight hard to make sure the dissimilar materials are used. It's also why the Democrats and Unions fight so hard against having good roads in Michigan, Ohio, and several other states.

In the county where I live in upstate NY, the Republicans have had a majority since the early 80's, and we use asphalt for paving and repairs on all of the county roads. In the surrounding counties, the Democrats use a mix. It's interesting how politics affect so many things that you wouldn't think of.

Re:Cement (0, Flamebait)

Planesdragon (210349) | more than 6 years ago | (#21880134)

In the county where I live in upstate NY, the Republicans have had a majority since the early 80's, and we use asphalt for paving and repairs on all of the county roads. In the surrounding counties, the Democrats use a mix. It's interesting how politics affect so many things that you wouldn't think of.
Name names, asshat.

I've never seen a road patched with dissimilar materials, nor could I imagine it being done for any reason other than cost. In Albany we've got a bundle of cobblestones under the roads, so we get cracks no matter what we put down. In Oneida, I lived on a gravel-and-tar road for ten years, that got a new "top coat" every year or two.

And I lived a few years in Saratoga County --which has a Republican Majority -- and found the roads to be as crappy as they were in the rest of the state. Worse, actually, when you account for the increased per-acre tax base Saratoga had.

Heck, I've never even heard of a Republican arguing that we need to raise money to completely re-do our broken roads. Not once. And in the five places I've lived in this country, the roads only ever get fixed when there's enough money to fix them.

What mythical republican island do you live in where roads are paved, while equally-well-funded neighboring counties waste their money by cutting corners to make more work for themselves?

Re:Cement (1)

bcattwoo (737354) | more than 6 years ago | (#21881926)

Wow, I am truly flabbergasted that this AC's BS gets modded insightful and the guy that calls him out gets modded flamebait. Most of the northern US uses "concrete" in the cold months because you can't apply a hot asphalt patch in the winter, when most potholes appear anyhow. If Mr. AC has anything to substantiate his claim, I would love to hear it.

Re:Cement (1)

whitehatlurker (867714) | more than 6 years ago | (#21878648)

I believe you mean concrete.

Re:Cement (1)

Marcos Eliziario (969923) | more than 6 years ago | (#21879620)

Oh. An Engineering-Nazi?

Re:Cement (2, Interesting)

eth1 (94901) | more than 6 years ago | (#21882672)

Actually, here in TX, you could use this to *cool* the roads. The extreme heat tends to crack and buckle the concrete. You'd also get some pretty hot water (even from the light-colored concrete). It's energy, and I'm sure someone could use it!

May as well bring back steam trains (-1, Redundant)

tjstork (137384) | more than 6 years ago | (#21877720)

The single biggest reason that steam locomotives lost out to diesels was because of the added cost of handling all of the water to boil. So, if we're going to run water under every road in the USA, forgetting for a moment that it would cost a ton of money and accomplish little in return, we may as well throw up a few water towers too for the old steam locomotives.

Re:May as well bring back steam trains (4, Insightful)

FroBugg (24957) | more than 6 years ago | (#21878016)

Except that your analogy is ridiculous. The proposed heat pump is a closed system. Stick the water in once and you're done. Using a pump to circulate it requires very little power compared to what can be saved in heating by using the heated water.

Yes, the construction costs will be high, but that's what a lifecycle cost analysis is for.

Re:May as well bring back steam trains (0)

Anonymous Coward | more than 6 years ago | (#21878984)

Worse than that, it's a load of bullshit. This is why condensers are a vital part of any modernish steam engine system.

Re:May as well bring back steam trains (1)

IdeaMan (216340) | more than 6 years ago | (#21887372)

I've been reading about steam engines for the last 2-3 months trying to decide if they are feasible to replace the IC, and my understanding at this point is that condensers are a mistake. The problem is that it takes a HUGE amount of energy to heat water at 212 degrees into steam at 212 degrees. A superheated steam cycle that doesn't have to reboil the water ought to be more efficient.
Yes, Closed cycle reduces the water usage problems, however even so Stanleys (old closed cycle steam auto) did lose significant amounts of water.

Re:May as well bring back steam trains (1)

tjstork (137384) | more than 6 years ago | (#21879002)

Yes, the construction costs will be high, but that's what a lifecycle cost analysis is for.

Sometimes common sense should apply and there's none in this plan.

a) Huge capital costs for construction. You need new asphalt for all the replacement roadways, and THEN, you need all of the materials for whatever you are carrying the water in. Then you have to transport it to whoever is going to use this heat.

b) Bad allocation of resources. One of the most pressing needs in any part of the world, even the United States, is for fresh water. So, you are going to tell everyone that you are going to divert millions of gallons of water that could be used for drinking and irrigation, to carrying heat. There's going to be annual losses and they are going to be massive.

Re:May as well bring back steam trains (1)

toQDuj (806112) | more than 6 years ago | (#21880400)

a) Well, you don't have to replace all roads at once. When placing new roads, you can incorporate the new tech. Wait with "tech-ifying" the old roads until they're up for replacement or servicing. The amount of new roads placed in the Netherlands is at such a high rate that I think it'll be about the maximum speed one _can_ install heat storage systems anyway..

b) so don't use drinking water then. Rain water will suffice just as well. Oh, and in the Netherlands, there's a lot of rain _and_ water.

I think if they're implementing this system in roads, they must have thought about things. Even my old university (Eindhoven) had a heat pump system installed some years ago, and they certainly weren't the first. Perhaps it's not common to have energy "saving" systems in the US, but here they've been around for a while. And they're profitable to have, due to energy (cost) savings.

Re:May as well bring back steam trains (1)

Firethorn (177587) | more than 6 years ago | (#21882244)

b) so don't use drinking water then. Rain water will suffice just as well. Oh, and in the Netherlands, there's a lot of rain _and_ water.

Actually, I'd think that they'd prefer to use distilled water with antifreeze agents added. Keeps the system from crudding up.

But I think that the point remains - despite water shortages, a system that you only have to fill up once isn't that big of a deal.

Most shortages are only during certain periods and in limited areas - while fairly expensive you could truck this water in from areas with a surplus. Or just wait until there's a surplus to start filling the pipes.

Re:May as well bring back steam trains (1)

toQDuj (806112) | more than 6 years ago | (#21882308)

In addition to that, the volumes required to operate such heat pumps dwarf in comparison to, say, the drinking water requirements of a large city.

Re:May as well bring back steam trains (1)

Firethorn (177587) | more than 6 years ago | (#21883144)

Quite right. I remember reading about a moderately sized city that had a 'moderate' leak in their water systems - they were losing over a million gallons a day from it, but didn't feel the need to fix it.

So the city, by fixing that leak, could easily afford the water to fill the road piping system.

Can't you just admit you're wrong? (2, Insightful)

spun (1352) | more than 6 years ago | (#21882536)

You failed badly in your analysis. Someone called you on it, and instead of admitting that you're wrong, you dig yourself in deeper. Do you want everyone to think you're stupid?

First, you have no idea what the capital cost of construction will be.

Second, the GP already said "that's what a lifecycle cost analysis is for." Duh.

Third, you have no idea how much water will be used. It will almost certainly be more than millions of gallons. Four hundred people use a million gallons of water in a day, for personal use, energy production, and industry. Per capita water use in the US is about 2,500 gallons a day. Your estimations are so far off base as to be laughable.

Fourth, that's not the point. We can easily use runoff from the roads, which is already contaminated and unfit for other uses. We can continue to use this source to replace any losses, and again, you have no idea of the magnitude.

You just spout words without understanding or any attempt at honest communication, just to try to sway people to your beliefs. It's disgusting to watch, like a retarded chimp flinging poo at passers by.

Re:Can't you just admit you're wrong? (1)

darkshadow (102598) | more than 6 years ago | (#21883400)

"We can easily use runoff from the roads, which is already contaminated and unfit for other uses."

And how long are those pipes going to remain unclogged?

Re:Can't you just admit you're wrong? (1, Insightful)

tjstork (137384) | more than 6 years ago | (#21883520)

Fourth, that's not the point. We can easily use runoff from the roads, which is already contaminated and unfit for other uses. We can continue to use this source to replace any losses, and again, you have no idea of the magnitude.

You just spout words without understanding or any attempt at honest communication, just to try to sway people to your beliefs. It's disgusting to watch, like a retarded chimp flinging poo at passers by.


The arguments you've made are unconvincing. I'm sorry. I'd rather have a million people call me stupid than be just another fanboi. In the end, I am completely right.

The GP would have us believe that we can take a solution that works for the tiny country of Norway and do it to the entire United States. That's absurd. Really, where are you going to get the water in the west? Hint - its a desert.

But even in the Northeast US, I don't think this one has been thought through. First we go from getting a lot of water from existing sources, and now, we're talking about collecting rainwater. That's all fine, but I thought we needed that rainwater to go back into the ground and replenish acquifers. Oh, and by the way, the original article has them pumping water into the ground to manage its temperature. They put water into the ground in Ohio already and they've found that there's environmental consequences of doing that as well - it's one of the reasons why you don't see geothermal everywhere.

But think about it, again, from a common sense level. All we're really doing is talking about exchanging the exploitation of one resource, for another, and I just don't think the implications have been thought through at all.

I'm certainly no environmentalist, and in fact, I think most of it is crap, but I'd certainly be proud to stand with them and block any proposal to turn every American highway into a water exchange heat pump until the proposals for doing so have actually been thoroughly studied, piloted in different geographic areas, and really, really understood. What you people are advocating is the kind of "let's just get 'er done" madness that screwed the world up to begin with. Call me stupid as much as you want, but I'm not hopping on board that train.

You're no engineer (1)

spun (1352) | more than 6 years ago | (#21883956)

I love how you say my arguments are unconvincing. Which ones? You refute nothing I've said. You have no idea of the scales involved. You are not an engineer. You are not trained in economics, nor in civil planning. You show your ignorance in everything you write. You make assumptions and treat them like they are self evidently true.

The thing is, the person you responded too said that more study was needed. I'm saying more study is needed. Pretty much everyone agrees on that. Your objections add nothing to the discussion. No one is advocating any kind of "let's just get 'er done" madness, that's just you putting words in our mouths.

You are not smarter than the people making these proposals. The idea that you have thought through the consequences and they have not is the kind of intellectual arrogance one usually only finds in teenagers. These are engineers we are talking about. Are you an engineer? I know that you aren't. No engineer would make the idiotic claims and simple mistakes you've made in your analysis. You are a blowhard with an agenda and no practical experience or knowledge.

Every Slashdot story about tech has idiots like you bringing up obvious fucking points as if the people who come up with these sorts of ideas are complete morons who can't put two and two together. The only reason you do it is to try to make yourself look smart, but that only works at places like digg where the audience are idiots too. Here, people see shit like that and they laugh at you.

Laughing Out Loud (1)

tjstork (137384) | more than 6 years ago | (#21884766)

I love how you say my arguments are unconvincing. Which ones? You refute nothing I've said. You have no idea of the scales involved. You are not an engineer. You are not trained in economics, nor in civil planning. You show your ignorance in everything you write. You make assumptions and treat them like they are self evidently true.

Let's see. Every engineer, civil planner and economist said that it was ok to build massive coal fired plants, give everyone a car, and pave over a bunch of the planet with superhighways. As a result, we've had rampant lead contamination, particulate emissions, and now global warming. We the people listened to you prop yourself up like Gods in order for you to build your fancy stuff, and endured as you called us idiots for merely suggesting the utmost in caution, and the result was an entirely screwed up planet because of YOUR ARROGANCE. Having completely wrecked the earth's atmosphere, you now want me to trust with you the water, using really, the same arguments. "We're so smart", you say. But, I'm looking at your track record, and you really aren't. Tell me engineer, what's the CO2 content in Hawaii, this year, from all of these wonders you built.

Defense rests.

Re:Laughing Out Loud (1)

spun (1352) | more than 6 years ago | (#21884968)

You don't even believe in global warming, you hypocrite! You put down environmentalists left and right, yet here you trot out vague environmental threats to justify your position. I'm not an engineer either, but I understand far more about these things than you do.

You don't think anyone even thought about how much water this would take? That's only like the most obvious question to ask. It's so idiotic that you bring something obvious like that up and expect to be lauded as insightful for it. You aren't being insightful, you are bringing up the most obvious point.

I've figured you out. There is a reason you won't let an argument die. There's a reason you post idiotic trash. You are a very, very lonely person, and you will do anything for some attention. Christ on a pogo stick, man, just ask. Don't be so damn confrontational. You stir shit just to get a response, not because you believe anything you write. That's why you write things that directly contradict other things you've written. You don't even care enough to stay consistent.

If you admit you're lonely and stir shit just to get a response, I'll keep talking with you. Otherwise I'll never post anything in response to anything you write, no matter how idiotic it is and how badly you need correcting. I will ignore you fully and completely.

Re:Laughing Out Loud (1)

tjstork (137384) | more than 6 years ago | (#21885648)

You don't even believe in global warming, you hypocrite! You put down environmentalists left and right, yet here you trot out vague environmental threats to justify your position. I'm not an engineer either, but I understand far more about these things than you do.

Actually, now you are guilty of the crime of over simplification. I believe that it doesn't matter whether or not CO2 is causing the planet to warm or not warm, but that, we do have to manage the level. We already manage the water levels of lakes and rivers, the fertilizer level in soils, and it only seems silly to not do that with the atmosphere.

Where I differ with environmentalists is in outlook. CO2 transfer credits, I believe, are a scam that won't accomplish anything. If you want to really manage CO2, then, we need to reduce emissions, and that means a massive federal nuclear power plant scheme, putting out a coal mine fire in China (do google that one, its quite interesting), and probably switch over everyone to electric cars of some kind, and also, we need to have active sequestration. I'm not against solar power per se, but, in the solar projects I've been with, (I write monitoring software), it just doesn't live up to its hype in the northeastern USA.

You don't think anyone even thought about how much water this would take? That's only like the most obvious question to ask

Well, obviously the scientists in Norway that built the road mapped it out. However, the idiot that read the article about a success in Norway and posted it in slashdot obviously didn't think about that in the context of the USA. And why should he or she? They only post hypy stuff like that to get us to argue about it, so they can get more money. It worked.

I've figured you out. There is a reason you won't let an argument die. There's a reason you post idiotic trash

Actually, I'm just genuinely smarter than everyone else, and, I'm only trying to save you from yourselves!

Re:You're no engineer (0, Flamebait)

tjstork (137384) | more than 6 years ago | (#21885124)

The only reason you do it is to try to make yourself look smart, but that only works at places like digg where the audience are idiots too. Here, people see shit like that and they laugh at you.

I don't really care about "here". I'm not writing to persuade the unpersuadable - everyone here thinks they are a genius and they yell past each other more than communicate. I'm writing to appeal to a right wing audience for a political campaign in the future. If I have a good track record of battling the liberals online, then, I get good political points from them. It doesn't matter if I win.

And, in that vein, let's ask some harder questions about this, since you've thought it through. Let's do it one state, say, Delaware.

a) Where exactly are you going to do this, because the major interstate, I95, is an overpass, where all the buildings are in Wilmington.

b) How far away can a building be from the road to get some heat benefit?

c) Where's the electricity coming from for the pumps.

d) How much water and what kind are going into the ground. Do you have computer models that accurately predict what might happen to the acquifer? Will this impact the Chesapeake or the Delaware River? Or even the Christina River?

Barney it up to 10,000 feet. The whole point of your plan is that, all you smart people screwed up the atmosphere with the last energy project(s), and now you want us dumb people to let you use the ground instead for a new energy project. We don't even know what's going on in the atmosphere, and now you are going to make the rash claim that underground has no impact?

The proposal is so ridiculous, that the one who is absurd is you for even suggesting that we build such a monster.

Re:May as well bring back steam trains (2, Interesting)

N3Bruce (154308) | more than 6 years ago | (#21886316)

Well, with the cost of coal [economist.com] being a fraction of the cost of oil, it might just make economic sense from a fuel cost standpoint to bring back the steam locomotives. Of course there will be problems, such as carbon and particulate emissions, boiler maintenance costs, and safety concerns (improperly managed boilers can fail catastrophically) which doomed almost all of the old steam locomotives to the scrapyards over 50 years ago.

Although there are a fair number privately operated steam railways operating as either scenic railways or rolling museums, both in the US and Europe, the Diesel-Electric locomotive or electrified railways continue to be dominant in most of the First and Second World. The technology exists [internationalsteam.co.uk] for building a new generation of steam locomotives which would address many of the problems of their 19th and early 20th century counterparts, and do it at much greater efficiencies, but there is hardly a groundswell of activity aimed at making this a reality.

How nice for this bridge. (3, Interesting)

victim (30647) | more than 6 years ago | (#21877742)

There is apparently a bridge in Fukui [treehugger.com] which does just this.

Sorry for that link to Treehugger, they are a black hole of links and I would not normally link, but they had the best English language article I could find in 3 seconds of googling.

Nothing new... (3, Informative)

tgd (2822) | more than 6 years ago | (#21877770)

Its not uncommon for some very high end houses to do this during the summer and reverse the process (to keep the driveway ice/snow free) during the winter.

Re:Nothing new... (1)

budgenator (254554) | more than 6 years ago | (#21881114)

That's called geothermal heating, or a heat pump. It's not common but it's not rare either, the driveway part is a bit over the top. Usually in rural areas a pond is dug which effectively becomes a solar collect several acres in size, a swimming hold and a source of fish. Sometimes depending on the condition and depth of the aquifer an array of pipes are just buried in the ground for a heat source and sink.

Re:Nothing new... (1)

tgd (2822) | more than 6 years ago | (#21881238)

No, its not called geothermal heating or a heat pump... thats something entirely different.

These are systems initially installed for the express purpose of keeping a large parking area and driveway clear of snow, which some more innovative people have taken to using for production of hot water as well during the summer.

Seasonal energy storage (4, Interesting)

Anonymous Coward | more than 6 years ago | (#21877806)

The article talks about storing energy in ground water. It isn't such a crazy idea. We used to do that kind of thing. Until the 1950s, the conventional way to keep food cool was in an ice box. Ice would be harvested in the winter and stored in ice houses. The ice would be delivered to householders in the spring, summer and fall. It worked well but was labor intensive.

The idea of storing heat in the summer and cold in the winter is viable technically. The capital costs are impressive though. To keep my house cool over the hot summer months would take many cubic yards of ice. The container would be very expensive but maybe not more than most people are willing to spend on an in-ground pool.

It could work. Cheap energy allowed us to forget things we used to do. Expensive energy would cause us to bring them back. The ice box, in some form, could easily return.

Re:Seasonal energy storage (2, Informative)

Mr. Slippery (47854) | more than 6 years ago | (#21878790)

The idea of storing heat in the summer and cold in the winter is viable technically...To keep my house cool over the hot summer months would take many cubic yards of ice.

Which is why you use the ground [wikipedia.org] instead. It spends all winter getting cool and remains cooler than the air in summer; it spends all summer getting warm and remains warmer than the air in winter.

Re:Seasonal energy storage (1, Informative)

Anonymous Coward | more than 6 years ago | (#21879436)

The wiki article you link to describes heat pumps. A heat pump allows you to work against fifty degrees (approx.) rather than the ambient air temperature. That is really efficient for air conditioning. The only energy you need would be that required to pump air and water. For heating, you have to supply the energy necessary to get from fifty to seventy. (Yes, I realize the explanation is over simplified.)

The idea of storing ice is that you have to pump much less water. You could do the thing in the other direction if you used a material with a phase change somewhere near eighty degrees ... now you're getting really expensive. Energy would have to get really expensive to make that worthwhile. Solar would be cheaper.

If you have a source of ground water, you don't even need a heat pump to air condition. Lacking that, you need a bunch of piping. In that case the idea of storing ice makes economic sense.

This is called a heat pump (3, Insightful)

Colin Smith (2679) | more than 6 years ago | (#21877824)

And they've been around for decades. You can buy a system today, in all civilised countries. They work in exactly the same way as your refrigerator.
 

Re:This is called a heat pump (0)

Anonymous Coward | more than 6 years ago | (#21880460)

Really? I can buy miles of highway like this at my Home Depot? The article isn't about new technology invented for this purpose, you stupid shitfuck. It's about existing technology used in a novel way. Dick. And your mom sucks, too.

Energy efficient meme (4, Funny)

youthoftoday (975074) | more than 6 years ago | (#21878052)

So they're using a series of tubes to make renewable energy? Seems like you can do anything on the internets these days...

Re:Energy efficient meme (1)

j235 (734628) | more than 6 years ago | (#21878374)

I'm surprised Al Gore didn't invent this one too!

"We're going to take all that heat and put it into, what I like to call, a 'Locked Box'".

Re:Energy efficient meme (1)

ScrewMaster (602015) | more than 6 years ago | (#21888922)

Yes, in the olden days they used to pump all the air out of the tubes and make radios out of them.

I thought of this before you... (3, Interesting)

Anonymous Coward | more than 6 years ago | (#21878084)

I use this same technique to heat my pool. When filling it up in the summer I get together all my hoses and connect them. After laying this ultra long on my driveway I simply run water slowly though it from the tap into the pool. The water heats as it travels the hose and by the time it gets to the pool its actually quite warm.

Re:I thought of this before you... (2, Insightful)

YrWrstNtmr (564987) | more than 6 years ago | (#21878614)

I use this same technique to heat my pool. When filling it up in the summer...

Why do you empty it in the fall? Treat it well when you're done for the season, and you don't have to blow 15-20-30,000 new gallons in the spring.

Re:I thought of this before you... (1, Informative)

Anonymous Coward | more than 6 years ago | (#21878652)

Ha, yes well this was before I got a permanent pool, before I had one of those huge rubber ones with the inflatable ring on the top. It was fair sized about 3.5 feet deep mabey 16 feet across. In hind site it did wast a lot of water but that is quite cheep here in New England and it only cost about 600$ compared to the few thousand it cost to get a permanent one professionally installed.

Re:I thought of this before you... (1)

Darth_brooks (180756) | more than 6 years ago | (#21879100)

He's probably not emptying it completely at the end of the year, unless it's a collapsible pool. We would drain about 12 inches at the end of the season to make the pool easier to cover and to prevent damage over the winter (Michigan winters, gotta love 'em). The water left in the pool gave it its structural integrity.

Freezing? (2, Insightful)

Dan East (318230) | more than 6 years ago | (#21878098)

If any of that water were to freeze it would turn the roadway into a cratered, cracked and potholed disaster.

Dan East

Re:Freezing? (2, Insightful)

hjf (703092) | more than 6 years ago | (#21878428)

you would have to be really stupid to use tap water on a system like that. add some antifreeze and that's it.

Bacon, what can't it do? Re:Freezing? (1)

mrmeval (662166) | more than 6 years ago | (#21879030)

How many millions of gallons of the stuff are we going to *make*? How much of an impact will all those chemicals have when, not if, but when they leak? Continuing upkeep and environmental cleanup have to be added in. Then there's producing all this wonderful stuff, the chemicals, steels, seals, wire, pumps, generators, etc. It takes energy, materials and labor which costs money. Once you've added up the total cost of owner ship then you compare that to the benefits.

Has anyone projected our energy needs to 2100? Has anyone figured out how much energy we could make maximum if we covered 90 percent of the earth in asphalt/solar cell/etc? ;)

Re:Bacon, what can't it do? Re:Freezing? (1)

sumdumass (711423) | more than 6 years ago | (#21879386)

You can have antifreeze that isn't toxic to the environment when spilled. A lot of the brine road department treat roads with is runoff from pulp piles at alcohol distilleries. IT normally runs into the rivers and ground without the slightest issues.

As for turning roads into eclectic generators, I'm willing to be that it would cost a lot more then you could ever recover from it. This idea is actually pretty old. But this doesn't mean we shouldn't study it to see if recent advances in tech make it more practical.

Re:Freezing? (1)

budgenator (254554) | more than 6 years ago | (#21881126)

you say that like it's different from what we have now.

Do they get in the way loop detectors used in the. (1)

Joe The Dragon (967727) | more than 6 years ago | (#21878162)

Do they get in the way loop detectors used in the roads?

Re:Do they get in the way loop detectors used in t (1)

Radon360 (951529) | more than 6 years ago | (#21883914)

If the tubes are nonferrous (which they'd likely be), they wouldn't cause a problem. However, if the pavement contained these tubes, it would preclude adding a loop detector after teh fact unless you can build the detector into an added top layer, which may reduce the tube system's effectiveness.

Broken pipe (1)

russotto (537200) | more than 6 years ago | (#21878244)

I think the maintenance issues will sink this idea on the large scale. The pipes have to be close to the surface to take advantage of the heat, but that's where they are exposed to the most stress from both traffic and weather-related expansion and contraction.

Re:Broken pipe (1)

Bayoudegradeable (1003768) | more than 6 years ago | (#21878386)

And while here in southern Louisiana we'd love to get some energy from the horrid summer heat, the shifting ground and perpetual sinking of our landscape will surely crack or damage the daylights (ha!) out of the pipe system. Either way, it's nice to see a working effort.

Re:Broken pipe (2, Insightful)

AmericanInKiev (453362) | more than 6 years ago | (#21878610)

Yup, it's the operating costs stupid.
4 minutes MTBF.

KGO morning Traffic report: "We've got quite a back up on 101 northbound, they've been chasing a leak in lane 3 for 2 weeks; hopefully they'll find it, and we can get back to using the road as a - um - road thingy."

Operating costs are often the unthunk Achilles heel. -almost as bad as opportunity cost, and cost of risk.

AIK

Re:Broken pipe (1)

Firethorn (177587) | more than 6 years ago | (#21882306)

They actually wouldn't necessarily need to be close to the surface - the deeper you go, sure it takes longer to reach the pipes, but you have to remember that you have all year. So by placing them deep you get a more even heat.

Interestingly enough, it might increase the lifespan of the road by keeping it at a more constant temperature.

problems (0, Redundant)

ILuvRamen (1026668) | more than 6 years ago | (#21878332)

I live in Wisconsin so believe me when I say putting warm water on a road to de-ice it is a very, very, very bad idea. Also if all the heated water tubes would be connected to a central area where they could turb a turbine, you'd lose so much heat from the transport (since the underground is cold) it wouldn't be cost effective. Now an actually good use would be hooking up people's waterheaters to the reverse radiation network of tubes under the road and let the road heat the water to supplement the water heater's job to save a lot of electricity or propane.

Re:problems (1)

AbsoluteXyro (1048620) | more than 6 years ago | (#21878774)

Um... I think the idea is to run warm water through the tubes to defrost the road, not spray warm water all over the road. Spraying water all over the road in the dead of winter would be super retarded.

Re:problems (0)

Anonymous Coward | more than 6 years ago | (#21878900)

They aren't spraying warm water onto the road (or into buildings for that matter)...

Frozen Ground (0)

Anonymous Coward | more than 6 years ago | (#21878406)

I live with permafrost, you insensitive clod.

It will work very well... (1)

frank_adrian314159 (469671) | more than 6 years ago | (#21879338)

... until a pothole develops under a pipe or until the surface is worn away and tires start tearing into the pipes and you start losing coolant in a thousand small leaks all over the system. If you want to screw around with solar heat-based energy generation, passive solar at the focal point of a parabolic collector is much less costly, is much less brittle, and is much easier to repair when it does break.

Farmer (1)

Eddi3 (1046882) | more than 6 years ago | (#21879572)

I don't have the story on hand, but I'll try to summarize as best I can:

There's this farmer out in the middle of nowhere, and one day the government decides they need to run a high way through his farm. They make a proposition to buy the needed land (not the entire farm, mind you), and he says okay, under one condition: That he be able to run pipes under the high way, and do whatever he wants with them. The government, not sure of his intentions, but thinking there's not much harm in it, says okay.

What the farmer did, was run pipes from under the highway, right into his house, keeping it heated for free all year.

AFAIK, it's true.

Re:Farmer (1)

scottv67 (731709) | more than 6 years ago | (#21879724)

There's this farmer out in the middle of nowhere, and one day the government decides they need to run a high way through his farm. They make a proposition to buy the needed land (not the entire farm, mind you), and he says okay, under one condition: That he be able to run pipes under the high way, and do whatever he wants with them. The government, not sure of his intentions, but thinking there's not much harm in it, says okay.

What the farmer did, was run pipes from under the highway, right into his house, keeping it heated for free all year.


I calleth bullshit! How much heat can be absorbed by pipes buried in a highway when the temp of highway's surface is 32 degrees F? The current temp outside my house is 0.7F. I would imagine that the road surface is not a whole lot warmer than the air temp. How much heat could I really expect to "harvest" from tubes running under the street? This is the time of the year when I could use the free heat.

Or is this technology designed for the warmer climates where the sun shins on the blacktop and the heat from the tires of passing cars makes the road surface warm enough that heat could be harvested?

How much does it... (1)

listen_to_blogs (1210278) | more than 6 years ago | (#21879606)

cost to build a system like this for a reasonably long highway(say 100 miles) and how much power(in watts) will it generate? listen_to_slashdot [blogbard.com]

Re:How much does it... (1)

Retric (704075) | more than 6 years ago | (#21883230)

Picking numbers from thin air let's say:

70 foot wide by 100 miles long * 100w /foot^2 at 15% eff = 554,400,000 watts or around 550MW.

Wow, What a Great Idea (1)

ryanisflyboy (202507) | more than 6 years ago | (#21879688)

This is a wonderful idea, until some moron with a jackhammer knocks out the heat to your building. Or worse, the pipes all freeze up due to a "computer monitoring glitch" - rendering all roads with this technology useless as the asphalt buckles and cracks due to the expanding water in the pipes.

It is time consuming enough when the local DOT decides to start digging up roads. Imagine if they had to lay miles of pipe under it too! Please put this in the recycle bin and move on to the next idea. This one has so many flaws I'm surprised it even made it past the bar napkin it was apparently designed on. One too many drinks for that engineer.

Re:Wow, What a Great Idea (1)

geek2k5 (882748) | more than 6 years ago | (#21886164)

According to the article, this 'flawed' engineering appears to work in an area that doesn't get a lot of sunny days. That tells me that the engineers involved are far from drunk.


Note that it collects heat in the warm season to be used in the cold season. A jackhammer or backhoe applied to the road or parking lot collectors wouldn't have much impact on the heat already stored. (They could, however, cut off gas lines and underground power lines, a flaw in 'modern' heating systems.)


Now the potential for freezing pipes and buckled asphalt does exist, though that can be minimized through simple techniques like draining the pipes when the heat collection season is over. People in climates that get snow on a regular basis are quite familiar with the concept of blowing out their sprinkler systems to prevent those pipes from freezing/breaking.


The DOT objection is a very good one in a limited sense. I wouldn't want the DOT to tear up my streets to install heat collection systems just to get them in place. But given the amount of space dedicated to parking lots in the United States, the DOT, or local equivalent, would rarely need to get involved. They could let the businesses with the parking lots do the work.


Now if DOT controlled streets ARE used for heat collection, it could be done in such a way that the collection system is put in when the street is upgraded or rebuilt/repaved. With the right planning, the additional work wouldn't add that much time to construction. The DOT could then charge people for the use of the heat collected.

My employer does this sort of thing for a living (5, Interesting)

LloydPickering (1211110) | more than 6 years ago | (#21880756)

I work for a company in the UK who installs road energy systems. Figured I'd finally register a slashdot account to respond to this article after lurking around for so long.

Here's a link to our supplier's page with installation photos for those curious. http://www.invisibleheating.co.uk/photos-of-asc-installation-g.asp [invisibleheating.co.uk]

The pipes are filled with anti-freeze rather than water. We use a vegetable based anti-freeze because of it's non toxicity should it leak.

The system is divided into zones, or sections which converge to a manifold. Each zone can be turned off individually, so if someone does damage a section of pipe, it can be turned off without affecting the rest of the system. Anyone who has underfloor heating should have this in place too.

We combine the system with geothermal heating and cooling using boreholes. In the summer excess heat from the building, and from the road is 'dumped' into the boreholes raising the average temperature of the local ground. In the winter we abstract the stored heat which then lowers the temperature back down. The entire system is 'closed loop'. We don't touch the groundwater itself at all, although we do also install open loop geothermal systems.

Inside the building is a heat pump, which (as stated above) works like a fridge, but in reverse. Its basically just a Copeland compressor. It takes in large quantities of water at ground temperature, say 12 degrees C, and compresses that heat into a tank of water (heating it to say 45-50 degrees C) and the water that returns to the ground will exit at something like 6-8 degrees C. Different systems are designed to work with different temperature gradients, so be aware that those are simply example numbers. The larger the difference in temperature, the more efficient the system which is where the road energy comes in. Storing the excess heat in the summer means for example the average ground temp isn't the aforementioned 12 degrees C it's 15 degrees C instead.

A more layman style description can be made using orange squash. Imagine you have a large volume of orange squash. If you find a way to remove some of the orange dilute from the squash you end up with a weaker orange squash, and a volume of orange concentrate. The heat pump works on this idea, except with heat instead of orange squash.

On the whole, systems are surprisingly economical for commercial customers. In the UK installing a geothermal heating system will generally have a payback period of around 5 years when compared to a natural gas boiler. The extra benefit is that you also get almost free cooling with the system whereas with a gas boiler you have to put in extra chiller units. As a final economic litmus test...we are installing a road energy and geothermal system for a small medical centre in the UK ultimately paid for by the NHS, and I'm sure even those outside the UK know the NHS is pretty frugal. ;)

Re:My employer does this sort of thing for a livin (2, Funny)

hoggoth (414195) | more than 6 years ago | (#21882324)

> takes in large quantities of water at ground temperature, say 12 degrees C, and compresses that heat into a tank of water (heating it to say 45-50 degrees C) and the water that returns to the ground will exit at something like 6-8 degrees C...

> A more layman style description can be made using orange squash. Imagine you have a large volume of orange squash...

I was having trouble following the process because I am unfamiliar with this "water" material you used in your example. Thank goodness you gave an analogy using "orange squash." Now the process is crystal clear because I am much more familiar with "orange squash" than water, as I'm sure is the case with most everyone reading this.

Re:My employer does this sort of thing for a livin (1)

LloydPickering (1211110) | more than 6 years ago | (#21883216)

Well, the analogy was aimed more at explaining the *magical* process of turning 12 degree C water into 50 degree C water that a lot of people find rather difficult to understand.

Thank you for your pedantry.

As a side note: Anyone with an allergy to citrus may at their own discretion substitute the orange squash in the analogy with any other form of diluted drink of preference.

Re:My employer does this sort of thing for a livin (1)

cromar (1103585) | more than 6 years ago | (#21887502)

I have no idea what be this "orange squash."

Re:My employer does this sort of thing for a livin (1)

TheBracket (307388) | more than 6 years ago | (#21888172)

"Orange squash" is a bit like Sunny Delight, but even nastier. Basically, take some orange concentrate, boil it with sugar (or substitute) into a thick syrup, and sell the syrup. It is then diluted heavily before being drunk. Some squash vendors throw in vitamins, colourings, and various other oddities as well.

i thought about this a few months back (3, Interesting)

foniksonik (573572) | more than 6 years ago | (#21882684)

This article doesn't mention the facts I'm interested in.

How hot does the water in the pipes get? Is it hot enough that if you swapped out alcohol for the water, the alcohol would turn to steam? (78.3 degrees C) Obviously the surface gets pretty damn hot but does that get through the asphalt into the pipes efficiently enough....

If so has anyone thought of running a nearby stirling engine to generate actual electricity?

My thoughts on this were that in a place like California or Nevada, where there are hundreds of thousands of miles of roadway and at least half a year of near cloudless skies, quite a bit of energy could be generated with little or no additional impact on the environment.

If enough energy was generated you could conceivably even run some public transportation on these roads using an exposed contact system such as a recessed rail... or just run a system parallel to the roads. The cost of transporting the energy to these locations for this use would have dropped to zero thereby making them much more economical.

Very old Paul Theroux concept (1)

gatkinso (15975) | more than 6 years ago | (#21886892)

He discussed asphalt solar in his 1986 novel O-zone. His characters were using it to make rain (and to drive up the price of oil, IIRC).

Hot Asphalt (1)

N3Bruce (154308) | more than 6 years ago | (#21887608)

Some additional thought would need to be made into the selection of aggregate materials for the asphalt. Here in MD, and in many other areas, once the surface coating of the actual asphalt wears or washes away, the exposed aggregate is actually almost white, where the aggregate is of certain types of flint, quartz, limestone, or marble. Many of the aggregates from established quarries would be poorly suited to absorbing heat, necessitating the establishment of new quarries, or having to transport more suitable aggregates long distances.
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