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Use of Asphalt Paved Surfaces For Solar Heat
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."
Physics professor Roland Winston, proposed this 25 years ago.
This could help reduce the overall temperature of blacktop services... which have this side effect in very hot summers of melting.
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.
There is apparently a bridge in Fukui 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.
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.
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.
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.
Deleted
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.
So they're using a series of tubes to make renewable energy? Seems like you can do anything on the internets these days...
-1 not first post
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.
If any of that water were to freeze it would turn the roadway into a cratered, cracked and potholed disaster.
Dan East
Better known as 318230.
Do they get in the way loop detectors used in the roads?
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.
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.
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.
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I live with permafrost, you insensitive clod.
Worse than that, it's a load of bullshit. This is why condensers are a vital part of any modernish steam engine system.
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.
This is my sig.
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?
I'd go on a Vegan diet but the delivery time from Vega is too long. --brownkitty
... 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.
That is all.
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.
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
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.
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.
Every experiment which ends in a big bang is a good experiment.
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
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. ;)
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.
I don't read AC A human right
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.
Every experiment which ends in a big bang is a good experiment.
> 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.
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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.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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.
A fool throws a stone into a well and a thousand sages can not remove it.
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.
I don't read AC A human right
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.
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.
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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.
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.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
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.
This is my sig.
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.
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Well, with the cost of coal 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 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.
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).
I am very small, utmostly microscopic.
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.
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I have no idea what be this "orange squash."
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.
"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.
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