Cooling Toronto Using Lake Ontario 698
An anonymous reader writes "Air cooled by the frigid waters deep in Lake Ontario started bringing relief to buildings in downtown Toronto on Tuesday after the valves were symbolically opened on the multi-million-dollar project. The company says that they have the capacity to air condition 100 office buildings or 8,000 homes - the equivalent of 32 million square feet of building space. They note that the cooling system reduces energy usage, freeing up megawatts from the Ontario's electrical grid, minimizes ozone-depleting refrigerants and reduces the amount of carbon dioxide entering the air."
Environmental effects (Score:5, Insightful)
I was going to ask about that... (Score:5, Funny)
Re:I was going to ask about that... (Score:5, Funny)
Re:I was going to ask about that... (Score:5, Funny)
Sure it can, but... (Score:4, Funny)
Re:Environmental effects (Score:5, Informative)
"...Brought to the John St. Pumping Station, the water's cold will be extracted and used to lower the temperature in downtown buildings. The water will then be treated and enter the city's drinking supply...."
So might be a double whammy, the water isn't directly injected into the lake again.
Re:Environmental effects (Score:5, Insightful)
Re:Environmental effects (Score:4, Informative)
Since this has been going on since the 1800's, I think you could probably estimate the environmental impact based on Chicago's experience.
Is Chicago out of luck? (Score:5, Informative)
There was an interview on the morning news yesterday with a guy who is a big fan of this technology. The interviewer asked him if this technology could be used in other cities on the Great Lakes. Yes, he said. There were various cities where it could be used. Rochester and Milwaukee were two examples he offered. But, he said, it could not be used in Chicago. Presumably because Chicago doesn't have easy access to a deep cold layer.
Here in Toronto we have always taken our water from deep in the lake too. As you can see from this map [noaa.gov] the depth drops precipitously just off Toronto Island.
The American fan of this technology was Alec Baldwin, the actor.
The interviewer next asked him if any of those other cities were considering following Toronto's example. He replied that he was flying to Chicago that afternoon to make a presentation.
Re:Environmental effects (Score:5, Funny)
Hahahahahaha. Perhaps they can keep these rooms lit by extracting the dark from them.
I tried that (Score:5, Funny)
RMN
~~~
Re:Environmental effects (Score:5, Insightful)
Here's a novel idea. How about we educate Joe Schmoe so he doesn't go around thinking completely backwards. If everybody were smart to a certain minimum level our engineers could stop trying to make a technical process understandable by explaining it either (a) incorrectly to the level of being the opposite of what is true, or (b) as though it were magic.
I realize Joe Schmoe would like nothing more than to sit back and watch his TV absorb darkness, but people commonly recognize that it actually emits light. If they can grasp that then they can grasp that the colder water is taking energy from the warmer water with a little effort.
Re:Environmental effects (Score:5, Informative)
I live just north of Toronto, in Markham (part of York Region).
We get our drinking water from Lake Ontario. All of the GTA (Greater Toronto Area), including the City of Toronto, York Region, Durham, Peel etc, use water pumped from the lake.
Our sewage is sent back down to Toronto, where it is treated before being dumped back into the lake. In fact, they're in the middle of building an additional set of sewage pipes to further growth in York Region (sort of controversial, because they're affecting groundwater and the Oak Ridges Moraine while they're doing it. Long story - google for details).
In other words, I don't think it would make any difference, because we've already been drawing our water from there. It's just coming from a different part of the lake.
Re:Environmental effects (Score:3)
Re:Environmental effects (Score:5, Informative)
Actually, water DOES flow down hill (Score:5, Informative)
As a grandson of a plumber I can confirm that the water does eventually end up back in the lake. Rule #1 of plumbing ...water flows down hill.
The beauty of this implementation is that the incremental warming of the water may actually further save energy if slightly warmer water comes into water heaters. From a thermodynamic standpoint this looks like a very large geothermal system. The economies of scale may make it quite cost effective too.
Re:Actually, water DOES flow down hill (Score:5, Insightful)
Re:Environmental effects (Score:4, Insightful)
You sound like you have absolutely no concept of just how big the Great Lakes really are.
These lakes are huge. I live on one of them. Calling them lakes is almost misleading. These really are inland fresh water seas. You can't see accross them!
The volume of these lakes is so large you aren't going to have any effect.
Besideds the amount of warm water dumped in by the Coal plant down the way has had little effect other than some very localized warming right by the outlet, This would be nowhere near as much of a temperature gradient even if they just dumped the used water back in. But they aren't They are essentially pre-heating the drinking water they have been getting out of the lake for a hundred years before they use it for drinking. Used water is the same used water that has alwaysed passed through the sewage plant
Re:Environmental effects (Score:3, Informative)
http://www.enwave.com/enwave/view.asp?/dlw c
Will DLWC warm up Lake Ontario?
* No. Enwave is not extracting from Lake Ontario's water and then directing 'warmer' water back to the lake. The DLWC project has been designed to draw very cold lake water - colder than what the City needs for its water supply - from Lake Ontario. Enwave will extract the extra coldness before the water is sent into the usual water supply system. Water from Lake Ontario is being used
Re:Environmental effects (Score:3, Informative)
In practice, one will see a small tempretaure increase in the vicinity of the pipelines, but they're probably ecolo
Re:Environmental effects (Score:5, Informative)
-Toronto cools off using Lake Ontario waters [greatlakesdirectory.org]
Re:Environmental effects (Score:3, Informative)
Re:Environmental effects (Score:4, Informative)
No, they aren't heating the lake. They are extracting a small portion of cold water from the lake, and sinking the heat into that water as it flows on its way to the drinking water purification system. The absorbed heat will be dissapated by the time that water returns to the lake through the sewage treatment system.
I'd agree with you that it would be a problem if that isolated part of the lake were being used as a heat sink, but that's just not the case. What IS happening there is that there is a net loss of colder water in that region, at that particular strata of the lake. But the fluid dynamics of water (and the persistence of temperature strata) will tend to disperse the effect over a fairly wide area. The comparison to 7 additional seconds of sunlight over a year is probably about as accurate as you can get without a lot more math.
I'm sure the reversal [chipublib.org] of the Chicago [lindahall.org] River [niu.edu] more than a century ago has affected Lake Michigan more than this will Lake Ontario.
Re:Environmental effects (Score:5, Insightful)
We have to recognise that any interaction we have with the environment is going to have some impact on it. This impact will by definition be negative if we characterise any change to the existing equilibrium as being negative. The smart thing to do is to spread the impact by interacting in lots of different ways on a lower level, rather than abusing a single resource, as we currently do with fossil fuels.
I applaud what they are doing in Canada. The more alternative energy sources we use, the better.
Re:Environmental effects (Score:5, Funny)
I've never seen such a concentration of good looking impressionable young ladies in my life. It's well worth the effort!
Re:Environmental effects (Score:5, Insightful)
Re:Environmental effects (Score:4, Insightful)
Yes, it sounds totally bogus to me, too. The amount of air that the turbines intersect will be completely insignificant compared to the total amount of air passing through the area. Plus, turbines don't manage to extract any great percentage of the energy out of the air.
Re:Environmental effects (Score:3, Informative)
So the area of the turbin = 30*30*3.14 = 2800sq m.
so 2800sq m * 5 = 14000 cu m/s (amount of "air" moving through the area covered by the blades.)
1 cu m of air weighs 1.3kg. So 14000 * 1.3 = 18200kg.
18 tonnes of air moves through the area covered by the turbine every second.
Kenetic Energy of 18000kg moving at 5m/s
= 0.5mv^2
= 0.5 * 18200 * 5 *5
= 227500 kg m^2/s
= 227 kilojo
Re:Environmental effects (Score:5, Informative)
I'm annoyed by all this hysterical nonsense over environmental effects on the lake. Apart from the fact that the heat input is trivial given the size of the lake (do you know what the heat capacity of 393 cubic miles of water is?) People think the lake is not some finite reservoir of coolness - no, it's a heat store, it cools down in the winter people! Consider the hitorical effect of tens of thouands of summers if that were not true.
In all this ranting, the very real envirnoemental benfits of reducing energy consumption and CO2 emissions get lost in the noise. I'd have expected better from the so-called technically literate.
Re:Environmental effects (Score:4, Insightful)
So 59000 tons of water heated one degree can cool 59000 tons of air 4 degrees.
Furthermore the lake has 27 million times more water than that, so cooling 59000 tons of air 4 degrees would warm the lake (average temp) 0.00000004 degrees.
Re:Environmental effects (Score:4, Informative)
Very slightly if the water is fed back into the lake. However water has a high specific heat capacity around 4.2kJ is required to raise one litre of water by 1 degree celsius. The water in this case is comming from a very large lake, so it would take a huge amount of energy input to change the temperature of the lake by any noticable amount.
There also exist methods of extracting heat from rivers and lakes for heating. So possibly these could be used in winter.
What are the envirnmental effects of this?
Most likely considerably less than dumping heat in to the atmosphere, which is how conventional air conditioning works.
Re:Environmental effects (Score:5, Funny)
Re:Environmental effects (Score:5, Insightful)
Re:Environmental effects (Score:5, Insightful)
Re:Environmental effects (Score:3, Informative)
When the pre-heated warmer water from nearer the surface falls down to replace the cold water that is removed, what happens? Does it say warmer, or does it cool down?
Re:Environmental effects (Score:4, Insightful)
Re:Environmental effects (Score:5, Interesting)
Re:Environmental effects (Score:5, Interesting)
Re:Environmental effects (Score:5, Informative)
Re:Environmental effects (Score:5, Informative)
According to a cooling calculator online, a 30x60 office building would require approx 23.5 million BTU cooling over the course of a month. This assumes the building is insulated (I'm sure all Toronto buildings are) and that it's longest wall faces the sun. It also assumes cooling 24 hours a day. (If somone out there is a cooling systems engineer or contractor, why not share the actual cooling needs for typical office builings?)
Based on the numbers (and assuming the cooling plant is fairly efficient) then you should be able to cool somewhere around 51 million such buildings for three months (about the max cooling season there) before you have transfered enough heat to raise the lake's temperature one degree. I suspect if you used accurate heat transfer numbers you'd find it would take even more time.
In other words, before you could make any significant difference in the lake temperature, the next winter should re-cool the water already as others have mentioned.
Re:Environmental effects (Score:4, Insightful)
Re:Environmental effects (Score:5, Interesting)
Re:Environmental effects (Score:5, Informative)
Re:Convection? (Score:5, Insightful)
The question is whether this kind of pollution is better than the carbon dioxide/refrigerant chemicals/coal power plant pollution. It is likely the answer is "yes".
Re:Convection? (Score:4, Interesting)
As with any change, there will be winner and losers. In this case, I think the extra heat could make far more winners than losers.
I used to work at a coal fired power plant, the outflow channel (where we dumped warm (but clean!) water) was a haven for fish. Everytime I went past the channel outside the plant, there were always people fishing. Employees could fish closer to the outlet and they would. I watched them and most didn't even bother baiting the hook there were so many fish! Large fish for that area of the bay.
Also an interesting fact about water (Score:5, Interesting)
hell, if you wanna see a good example, look at the bottom of the ocean where there is no sun, but there are volcanic vents, the water at the bottom of the ocean isnt hot due to that, and that's more constant heat output than any city could produce in a million years.
Re:Also an interesting fact about water (Score:3, Informative)
where I said elements I meant liquids
and the reason the water wont get warm is that the warm water will rise above the cold water, and when it cools it'll sink.
water's interesting in what it does.
Re:Also an interesting fact about water (Score:4, Informative)
You also meant 4 degrees C, not a few hundredths. Below that point, the molecules are slow enough for hydrogen bonding to begin dominating their interaction, and the structures that form take up more space than the unstructured liquid, meaning it's less dense, meaning it will rise above the denser water which is (at this temperature) slightly warmer.
If you notice, you also meant "less dense", not "lighter". H2O has the same mass/mole at any temperature (and the same weight too given equal gravitational acceleration).
Water is, indeed, interesting. Let us know when you're fully awake.
Re:Environmental effects (Score:3, Interesting)
What damage it causes inbetween I do not know, but I do know that it has to be looked at. We have made too many mistakes assuming such things were harmless.
Re:Environmental effects (Score:3, Insightful)
Re:Environmental effects (Score:5, Informative)
Taking deep water, warming it, and returning it disturbs the system, and it would be prudent to understand the effects of that disturbance. If the city's already doing that for drinking and washing, well, now they are doing a whole lot more of it and the effects will be more pronounced, so again it's prudent to understand the effect of increasing the pressure on the system's equilibrium.
I don't study large lakes and I don't know what significant effects, if any, might be expected. I just hope that someone *does* study this particular lake and *does* understand the issues and *was* consulted.
I do hope it works out well. It's a nifty idea.
Finally, this ignorant Yank must admit that his first thought was, "Toronto needs *cooling*?"
Re:Environmental effects (Score:4, Funny)
Re:Environmental effects (Score:5, Informative)
I assumed standard water (1 kg/L) when converting from volume to mass. I also used only two significant digits for specific heat capacity (4.2 kJ/KgK). I also assumed uniform temperature and uniform heat distribution because I'm looking for averages, to get an idea of order of magnitude.
Anyway, I RTFA and saw that the cooling power is only about 207 megawatts. That convinced me to rule out any macroscopic environmental consequences and get on with my life.
Mod parent down - untrue (Score:5, Informative)
Re:Mod parent down - untrue (Score:5, Funny)
Re:Environmental effects (Score:4, Informative)
and when they take the coldness the water then goes into the city's potable water system. RTFA!
Re:Environmental effects (Score:5, Informative)
Re:Environmental effects (Score:3, Insightful)
But how long will it take that layer to be eroded? Also, it isn't replaced by surface water. The water directly around it takes its spot. We're still talking about water that's 83 meters below the surface.
Precisely. It would take a *LOT* of pumping to get that much water o
Re:Environmental effects (Score:3, Insightful)
Re:More environmental effects (Score:3, Funny)
Wrong lake. Cleveland is on Lake Erie. Perhaps you're thinking of Rochester.
Re:Environmental effects (Score:5, Insightful)
Nice :) (Score:5, Insightful)
Ok, it costs a lot of money, but in the long run it has the possibility to save so much more than money: the enviroment.
You have never been to Niagara Falls, have you? (Score:5, Informative)
Lake Erie and Lake Ontario have about the same surface area. But Lake Ontario is much deeper and so has a greater volume. I have links here to charts showing the temperatures, at various depths across various slices of Lake Erie [noaa.gov] and Lake Ontario [noaa.gov].
Note that Lake Erie is much warmer. But most of the water in Lake Ontario came from Lake Erie? Why is it so much colder? It cools off in the winter time. It takes water from the Niagara River six years before it flows down the St Lawrence.
If, for the sake of argument, Rochester, Kingston, Hamilton all used deep lake cooling, and they all grew so much that they exhausted the Lake's deep layer, Lake Ontario would still not evaporate, any more than Lake Erie evaporates away to nothing.
Yes, there are deep areas of Lake Ontario that have been at 4 degrees celsius for a long time. How long? Since the last ice age? The glaciers covered the entire Great Lake basin a few tens of thousands of years ago. So that is how long a unique deep lake water ecosystem would have had to evolve.
How much water would the cities have to draw from the deep layer to use up all the cold layer? I don't think you understand how deep the Lake is, and how great its volume. Look at these three maps. West [noaa.gov] Centre [noaa.gov] East [noaa.gov]. So, lets say the deep layer is currently something like half to one third of the volume of the lake. The cities would have to use up the equivalent of the flow of two or three niagaras worth of water in order to drain all the deep cold water.
So long as our winters continue to get cold enough for the lake to cool to 4 degrees the cold layer gets regenerated every winter.
I think it could be argued, if Global warming every gets bad enough that using deep lake cooling exhausts the cold layer in mid-summer that, since we have the infrastructure in place, we use it every summer until it is exhausted. What about the cold deep lake water ecosystem? I am all for preserving interesting, unique ecosystems. But I doubt that a few tens of thousands of years is long enough for it to become interesting and unique.
Just two questions (Score:5, Interesting)
(1). What will happen when the lake water will be warmed up? Ok,it will perhaps take a long time,but...
(2). How does the energy required for pumping / distributing the water and maintaining pipelines and machinery compares with electrical conditioneers?
Said that, it looks like a nice idea.Re:Just two questions (Score:5, Informative)
Q2 is apparently answered in the article. Approx 25% of the energy requirements for electrical air con.
Re:Just two questions (Score:5, Informative)
1 - Lake Ontario doesn't freeze over, but it does have some surface ice in midwinter. Ice implies a surface temp at or below 0 degrees c. Right?
2 - Having lived next to another sizeable lake (Lake Champlain, which typically does freeze over), and as an EXPERT in hydrodynamic modelling, I can assure you that that niggling little physics detail about water having maximum density at... (drum roll) 4 degrees C is accurate. However, twice a year, lakes like Ontario have all their water churned about as ambient average temp falls below 4 degrees C, then as ambient temp rises above 4 c. Wierd, but true. Frankly, seiche's are wierder [wisc.edu].
3 - So, as winter gets cold enough, any water not AT 4 degrees C rolls to the surface, where it is... say it with me... chilled by the Toronto winters. Before any ice is made, everything in the lake chills to 4 degrees C (this is my biggest oversimplification here, since inversion layers can exist in large water bodies. It doesn't matter in the overall calcs to follow, since all I was interested in showing is the mechanics for recharge of the cold zone).
4 - The thermal mass of Lake Ontario (one site says 86 m average depth, x 19,000 km^2 in area... 19,000,000,000 x 86 x 100 ^3 cm^3 per meter x 1 degree c x 0.0039683 btu's per calorie x
The Fact Sheet on Enwave's site [enwave.com] says they're gonna free up 59 megawatts. Now, I should be able to disregard a part of this as an efficiency improvement (electricity for cooling is gawdawfully inefficient, compared to non-compressive heat exchangers like this'll use), but I'll eat the inefficiency because that's the nice guy I am. 59 x 24 x 365 (megawatt-years to megawatt-hours) gets us *finally* to matching units. If I haven't completely bolluxed the calculation, we're looking at a capability of handling 3673 of these facilities. Or, the temp of Lake O going up 1/3673 of a degree.
Oh. Yay. The little fishies aren't even going to notice this. In fact, there's room for exporting this capability and if we're willing to warm Lake O by a few degrees I think it'd take care of the AC demands of most of North America, if them clever Canadians can just figure out a way to export this.
When she's working hard, the sun 'wastes' enough energy warming up dirt and water around the world to fuel our needs a thousandfold over. When she's not paying attention (at the poles, nights and winters), earth's radiating it off like gangbusters.
The risk of us boogering up our surroundings when we do BIG things is a valid one. But not here, not yet.
We've reached the point where we're influencing the world in several spots: cfc's, pesticides, acid rain, particulate emissions, garbage, animal populations, etc. etc. etc.
But this isn't one of them. As a side joke, I bet there are a few million Toronto residents that'd be more than happy to let the thermal average temp of Lake O go up 30 degrees, just for the lake-effect warmth it'd impart on their town each winter and the ability to swim without turning blue in midsummer. Back during a nasty winter ('93), a favorite bumper sticker of mine was 'Another Vermonter *for* global warming'.
Rock on Toronto & Enwave.com
Re:Just two questions (Score:5, Insightful)
You and me both :P.
Just to amplify your already excellent response, the other thing people here are forgetting is that Lake Ontario isn't a closed hydrolic system. It is fed by hundreds of rivers which dump tons of sun-warmed water into the lake in summer, and which dump tons of frozen and near-freezing water into it during the winter and spring thaws.
This input vastly outnumbers the amount of cold water the Enwave system will be extracting, along with vastly outnumbering the amount of warm water input to the lake.
In the end, the lake will be the same as it's always been, and less air-polluting fossil fuels will be required to run the existing air conditioning systems. Looks like a win-win situation to me.
Yaz.
In a related story... (Score:5, Funny)
The temperature of the lake has inexplicably begun to rise. Algae blooms, moss growing on surronding trees and Corona beer bottles scattered on the shore have alarmed the Canadian Department of the Interior to take swift, albeit expensive action the save the ecosystem of the lake.
Messing with lakes: NOT a good idea (Score:5, Interesting)
Not that I'm predicting this will happen here, but it's usually best not to heat deep water like that.
Re:Messing with lakes: NOT a good idea (Score:5, Informative)
Lakes 'turn over' like this when there has been long-term stratification of the water. Stratification occurs when a layer of warm, less dense, water forms over the colder, denser, lower layers. This is stable since the heat of the sun reinforces the stratification. Only a seasonal reduction in sunlight, or strong winds, can mix the layers.
Lake Nyos is in a tropical area where there is a permanent, marked stratication due to year-round abundant sunlight. Since mixing of layers is so rare, hug amounts of gas can accumulate in lower layers. This is dangerous should something trigger a rapid breakdown of the stratification - such as the landslide in Nyos.
In temperate areas stratification is confined to the summer, only then is there sufficient sunlight. In other seasons stratification breaks down and mixing occurs such that a potentially dangerous build up of gas is not possible.
Re:Messing with lakes: NOT a good idea (Score:5, Informative)
The answer is in the article. (Score:5, Informative)
that feeds from the bottom of the lake to cool down
a closed loop system, which is then used to cool down the offices/homes. No warm water is fed back into the lake. So the lake should not heat up at all.
The lake is NOT warming up ! (Score:5, Informative)
Look at the diagram on http://www.enwave.com/enwave/dlwc/ They warm up the city's drinking water by a few degrees.
A
Re:The lake is NOT warming up ! (Score:5, Interesting)
On the other hand, since the cold water is being taken from the lake now rather than warmer water, the thermal barrier between the warmer top water and the lower cold water may slowly lower (and it is a very sharp layer, not the gradual drop in temperature you might expect). This may indeed have some effect, but that doesn't seem very likely.
They could have gone the simpler and more direct route of just building a power plant that used the difference in tempersture between the cold bottom water and the top water to pump up that water and generate electricity. Such plants have been proven to work with ocean water, and should be even simpler in an environment without salt water's effects. I'm assuming they didn't because in Toranto that top water would also get pretty cold in the winter. Still, I don't expect they will need much air conditioning in the winter anyway, so a seasonal power plant might have been as good or better of an idea.
Re:The lake is NOT warming up ! (Score:3, Informative)
Anyone who lives around Lake Ontario knows how freaking cold that lake is, even when it's high 90's out, humid as hell, you can turn on your cold water and get freezing water out all summer, it's because this is a large deep lake. I live in a different city (still on the great lakes) yet the cold water is noticable warmer in the summer months due to the lake that it draws from being so sha
The London Underground is also doing this (Score:5, Informative)
Here's the BBC's story about it [bbc.co.uk].
And more importantly, Alec Baldwin was there (Score:3, Informative)
The Toronto Star's coverage [thestar.com] has more info about Alec Baldwin's participation in the launch of the Deep Lake Water Cooling system:
"The cold is extracted"? (Score:5, Interesting)
This is what renewables are about (Score:5, Insightful)
Natural Laws. (Score:5, Funny)
'the water's cold will be extracted and used to lower the temperature in downtown buildings'.
Unit for Cold anyone?
Re:Natural Laws. (Score:5, Funny)
The theory of cold is just a part of thermodynamic theory of darkness [ox.ac.uk]
The unit for cold is derived from unit for darkness and equals D.s, where D is unit for darkness and s is second.
Another link (Score:5, Informative)
No registration required;
http://www.cbc.ca/story/canada/national/2004/08
Do building ACs use refrigerants? (Score:3, Informative)
I know that "real" portable cooling units have no refrigerants (the corp I work for resells some).
I can see the savings from power, but I still don't like the idea of sucking cold water from the bottom of a lake. It would seem to me you could upset the balance and possibly cause the lake to flip thereby releasing tons on CO2 - something which happened in Africa, which did kill a lot of people.
Show me the numbers (Score:4, Interesting)
It's a GREAT Lake (Score:5, Interesting)
Did I mention it's big?
Plus water turns over automatically at 4C (that's the temperature when water is it's coldest). Lake Ontario is not meromictic and has a natural turnover anyways.
Re:It's a GREAT Lake (Score:3, Informative)
This has been around for a long time (Score:4, Informative)
The General Motors Technical Center in Warren, MI has been using open-loop cooling for decades, using the large pond on the campus as an open-ended evaporator. The fishes that live in it don't seem to mind.
There's a nice picture here:
http://www.bcausa.com/projects/tax_gm.html
(Pictured is the "Design Dome" the design building to the right, general engineering in the buildings above the pond, and the Cadillac, Chevrolet, Pontiac and mid-lux buildings beyond)
This is happening elsewhere (Score:3, Interesting)
I hate this (Score:3, Interesting)
These days those quasi-socialists have it all over us...
Similar implementation (Score:5, Informative)
Geothermal Heat Pump (Score:3, Informative)
You can find more infomation here [anl.gov] and here [southerncompany.com]
As a pedestrian I welcome this (Score:4, Interesting)
Have you ever had an errand in the downtown office area, and walked through a big blast of hot air?
Not only does this save energy. But because those downtown buildings are not using conventional air conditioners for cooling, they are not dumping megawatts of waste heat into the outside air. I read that the use of this technique should reduce the local ambient air temperature on the downtown streets, where it is used, by several degrees.
As a pedestrian I welcome this.
Re:As a pedestrian I welcome this (Score:4, Interesting)
In fact, Denver International Airport was ripped for choosing to do a white cloth roof. But once it got out that DIA would be running A.C. 24x7, then it became apparent that the roof lowered the heating costs. I first became aware of the need for a.c. in large buildings when the sears tower and O'hare were running a.c. while the outside temp. was -40F/-40C.
Residential applications? (Score:4, Interesting)
You'd dump warm water back in, but this could be augmented somewhat by holding tanks and underground piping that cooled it back to ground temperature. If the lake was man-made, the environmental effect would be essentially nil, and you'd only have to worry about thermal calculations.
This might not make sense for retrofitting, but what about for new developments? People like lake/park areas, and there's no reason that a cooling pond couldn't be framed in a naturalistic setting.
I suppose it all comes back to commercial viability; it'd take a more expensive air conditioner capable of combining water cooling with electrical compressor cooling, the "community" would be responsible for the cooling pond and piping, and the electrical savings might not matter.
Re:Residential applications? (Score:4, Informative)
Like its much more energy efficient to use chilled water a/c with a large central cooling tower. Then pump chilled water out to each home for use in chilled water a/c units. Large office and university campuses do this. But, at several million dollars, the investment is just too much for developers.
Re:The lake WILL warm up (Score:4, Informative)
Did no one RTFA???
You've already extracted from the exact same source of water for decades, for use as drinking water. This just raises the temperature of your drinking water by about 10C, with a net "gain" derived from reducing AC costs to the city.
So yes, you can technically say that removing water from the coldest part of the lake raises the average temperature. But to turn that into "we should not be doing this" ignores the reality of the situation. This results in less energy consumption overall, a good result no matter how you look at the situation.
Re:The lake WILL warm up (Score:3, Interesting)
Re:The lake WILL warm up (Score:4, Insightful)
What's the alternative here? Apparently there is none, so we better just not cool those homes.
I recommend you take a much needed chill pill (Score:5, Insightful)
Yeah, the equivelent of eight extra seconds of sunlight hitting the lake will be death to the entire eco-system! Run away, run away! Burn freighters full of fuel and oil instead! (RTFA if you don't get the reference)
Get a grip. YOU have a much bigger impact on the eco-system every day you use heat, airconditioning, refridgeration, eat, sleep, shit, work or play.
The hydrocarbins the manufacture and use of the computer you typed your comments on probably have a larger impact on global warming than this entire project. The Canadian's approach is the smartest solution to this problem that anyone has come up with in a long time. Is it scalable to every city on the coast of that lake? No (8 seconds of sunlight is one thing, eight days equivelent would be another), but that doesn't mean we shouldn't be doing it in order to reduce the consumption of power in other areas.
Nothing is a panacea, but this is a damn sound solution for Toronto, and they get to do it by being there first. Any overall solution to our energy, global warming, etc. problems will involve numerous clever solutions, and this project stands a good chance of being a part of that solution.
And as for impacting the environment: 6 billion people breathing the air impact the environment. If you truly don't want to have an impact, slit your wrists. Oops, your decaying flesh will still have an impact, so you're out of luck there too. Better get used to it, because people do have an effect, and they always will. The impact of this project is benign and minimal, compared to every other public works project out there, including the sewage system in your town you probably make use of multiple times every day.
Re:5 Tonnes CO2 per Car?! (Score:4, Interesting)
1 Imperial gallon of petrol ~8lbs. Stoichiometric combustion requires 14.7:1 air:fuel ratio by mass, so burning that gallon in travel requires about 118lbs of air. Estimate about how much fuel you burn in a year, multiply by 118 (or 95 for US gallons) - and suddenly five tonnes of CO2 as a byproduct is eminently feasible.
Example: SUV driven 18000 miles/year at, say, 15mpg US: 114,000lbs of air consumed, representing nearly 24,000lbs of oxygen to be bound up in combustion products. That's TWELVE tons of shit right there...