Cooling Toronto Using Lake Ontario

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

[jonbryce]

Will this not cause the lake to warm up? What are the envirnmental effects of this? Have they been considered?

Nice :)

[Killjoy_NL]

This is the kind of stuff I like to see :)

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.

Re:Environmental effects

[black mariah]

Why would it? It's just siphoning off water on the bottom and moving it elsewhere. Unless the lake gets catastrophically low (the pipe's 83 meters down), there should be no issue with water warming at all.

Enviromental effects seem to be quite minimal. Water is taken for drinking supplies anyway, and all they're doing is channeling it through a different set of pipes. I'm pretty sure that the enviromental effects were considered, as it's far better to shut stupid Greenpeace hippies up before they can start their jaw flapping.

Like co-generation

[Anonymous Coward]

From the diagram, it looks like the cooling water goes into the city water supply where normally the cooling effect would have been lost as the water flowed through the city's water infrastructure. Conceptually it looks like co-generation, but for cooling.

Re:Environmental effects

[jonbryce]

If you take cold water from the bottom, then surely it will be replaced with warmer water from above. Is there anything that makes the water cool down once it is in the lake?

Re:Environmental effects

[hcdejong]

The water may not be returned to the lake again, but the 'bottom layer' of 4 deg C water will get thinner, as the water that's pumped out is replaced with surface water that has a higher temperature.
Maybe the cooling capacity of the lake bottom is high enough to counteract this, though.

Re:Environmental effects

[black mariah]

The water at the bottom of the lake isn't special. The only reason it's cold is because it's so far away from the surface that it can't be heated by the sun, and the water on top helps wick away any heat that might build up. Go dive into a lake. The first few inches of the surface might be warm, but down as little as five feet you're looking at a significant drop in temperature, and it just gets colder as it goes down.

Re:Environmental effects

[VeryProfessional]

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.

This is what renewables are about

[T.Hobbes]

For me, at least, this is what renewables should be about: finding a local source of economical renewable energy, and applying the appropriate technology to make it useful. The key thing, though, is that the methods change depending on what's availible locally.

Re:Environmental effects

[black mariah]

the 'bottom layer' of 4 deg C water will get thinner, as the water that's pumped out is replaced with surface water that has a higher temperature

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.

Maybe the cooling capacity of the lake bottom is high enough to counteract this, though.

Precisely. It would take a *LOT* of pumping to get that much water out of the lake. I'm willing to wager that a typical summer takes more water out of the lake in a year through evaporation than this will in a decade. But don't quote me, because I know no specifics beyond the article.

Re:Environmental effects

[black mariah]

It cools. How do you think the water got cold to begin with?

Re:Environmental effects

[gowen]

Well, as I understand it, that water was getting pumped out of the lake anyway... But given how cold Ontario gets in winter, the Canadian winter probably cools the lake enough in the winter for it to act as a pretty efficient renewable heat buffer.

Re:Environmental effects

[mdfst13]

From where were they getting their drinking water previously? My first guess is that this just substitutes water taken from the bottom of the lake for water that would otherwise be taken from the top. Net change in water levels (vs. not doing this) would thus be negligible.

Re:Environmental effects

[beh]

But is this comparable?

In this case, we're heating a very cold (and potentially very isolated part of the lake) as opposed to the sunshine spreading its energy all across the lake.

Picture this: Normal sunlight on a warm and sunny day warms up your skin - but drink plenty, and it won't harm you (too much). But if you take a lens and focus even only a small part of that sunlight energy on a particular place on your skin - and no amount of drinking cold drinks is going to prevent the pain...

This isn't saying we shouldn't do, what they're doing in Toronto - anything we do is going to have consequences in some shape or form anyway. But at least, we should keep a very close eye on it - and even monitor different parts of the lake that (to our knowledge) should be relatively untouched by this thing.

Re:Actually, water DOES flow down hill

[gowen]

The scematic does not show the back half of the municipal system (sewer and waste water treatment).

Well, yes, it does. Eventually. But by that time, the heat it gained in the exchangers has long been dissipated, so it's irrelevant. Waste water from this source will be no warmer than the waste water that was previously reaching Lake Ontario.

Re:Environmental effects

[Mysticalfruit]

There talking about 8,000 homes so I can imagine it's not that much water. If they were going to be cooling the whole city via this method then I'd start to worry.

Re:Environmental effects

[gowen]

The problem is that after thewind has past through that, it's no longer strong enough to push clouds,

Do you have a source for this. I find it extremely difficult to believe, given the height of clouds, compared to the height of wind turbines...

Re:Environmental effects

[black mariah]

I don't dislike Greenpeace's general goal, I think their concerns are generally well-founded, but the rather idiotic stunts they pull are flat-out dumb to anyone with half a brain. I seriously wish there were some environmental groups that had *SANE* members. Unfortunately, I have yet to see one.

Re:Environmental effects

[Henk Poley]

I don't think so, as since people will now use less electrical cooling methodes so you need to generate less electricity (equals to less cooling needed for the powerplants).

Re:Environmental effects

[david.given]

Do you have a source for this. I find it extremely difficult to believe, given the height of clouds, compared to the height of wind turbines...

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:water warming?

[Anonymous Coward]

Because some folks understand how fragile a natural balance can be, are prepared to look further than immediate future and don't swallow everything they read as gospel.

Removing the cold water will increase the overall temperature of the lake, that much is certain. Not by much, but over an extended period of time it may make a big enough difference to be damaging. So it is possible that this perceived 'green' project might just be switching one kind of damage to the environment for another. Before anyone strawmans me I'm not saying this project will definitely destroy the lakes ecosystem or that the removal of the water will be sufficient to warm it enough to cause problems. Just that it is a possibility. Frankly I'd be more worried if people were not asking this question.

To me it seems to me more about freeing up electrical energy in the area to ease power distribution problems rather than an attempt to be eco-friendly. Which is a goal with its own merits. It has been painted 'green' to increase its profile and encourage its acceptance. But then I am a level 16 cynic. ;)

Re:Environmental effects

[modge]

I do hope they like drinking tepid water though :P it wont warm the lake up i argeee with every one there, but the drinking water....now that will be pleasent. or do poeple not drink tap water in toronto?

Is This Saving Any Money??

[Anonymous Coward]

Is this actually saving any money? Sure, it's reducing the energy consumption, but how are the businesses being charged for this new installment (since they will no longer have to heavily rely on AC)? Is the city flipping the bill?

(I know.. RTFA, but it's early yet)

5 Tonnes CO2 per Car?!

[Anonymous Coward]

Quoting the article:

"[This is] clean, renewable, reliable energy. Compared to traditional air-conditioning, Deep Lake Water Cooling reduces electricity use by 75 per cent and will

eliminate 40,000 tonnes of carbon dioxide, the equivalent of taking 8,000 cars off of the streets of Toronto."

Am I to understand that one car produces 5 tonnes of CO2? What kind of cars are you driving up there? Geez, buy a hybrid or something!

All kidding aside, how do people get away with statements like this?

Re:Environmental effects

[vidarh]

You're assuming a closed system. Since when did a lake become a closed system? As many others have pointed out: Consider colder seasons, rain, cold water entering from rivers etc. Now, look at the other side: Consider the consistent heat added by sunlight and warm air over the entire surfae of the lake. Want to bet that this project is going to be lost in statistical noise if measuring the total energy input and output of Lake Ontario?

Re:Environmental effects

[SerpentMage]

Is it so neglible? From their home page they have 59,000 tons of capacity. 59,000 tons of cooled air is not insignificant. Do some heat ratio calculations and many many thousands of tons of water will be circulated every hour. That removed water will have to be replaced by warmer water.

The problem with their approach is that they are pulling cool steady state water, as 4 degree water is the densest. The water that you call a heat store is at higher levels. The water that they are pulling is the water that is the result of thousands and thousands of summers.

There is a VERY SIMPLE solution to this! USE LESS AIRCONDITIONING! It annoys me how people in North America overdo it with the air conditioning. Usually I have to put on a sweater because it is too DAMM cold. I used to live on the Cote D'Azur and people rarely had air conditioning even though the entire summer hovered between 21C in the night and 33C in the day. There are few places that REALLY need air-conditioning on the level used in North America.

Re:Environmental effects

[Anonymous Coward]

Water has 4 times the heat capacity of air (4kJ/kg vs. 1kJ/kg).

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:The lake WILL warm up

[mbourgon]

No, the point is that environmentalists don't want alternative fuels or alternative practices. They want less technology. Less tech = less electric used. I'll probably get modded as troll or funny, but I'm serious. Wind energy is touted - until someone wants to use it (New England wind-farm fight).

What's the alternative here? Apparently there is none, so we better just not cool those homes.

Re:Understandable lies are worthless

[forgotten_my_nick]

One of the hardest things in science is trying to dumb it down so the common Joe can understand it.

Re:Environmental effects

[An dochasac]

Forgot the link, and me login: Toronto's solution will have far less impact than Milwaukee's solution of building more coal power plants [greatlakesdirectory.org] which will suck 2.2 billion gallons of water and fish from Lake Michigan every day and convert it to mercury contaminated steam, or discharge it at a much higher temperature... all in order to inefficiently cool buildings to the temperature of lake michigan, a stone's throw away from the power plant. Can I burn some karma points with a duh here? Canadian industry finally cops onto an idea that every 7-year-old has when his toes are in 40F degree water and his head in 100F air. If only American industry wern't so hung up on our industrial past, we could see the way to the future.

Convection?

[wikdwarlock]

But, won't introducing warm water back into the lake add new convection currents that will stir things up, affect the lake's organisms, and add certain cleaning chemicals/pollution?

Re:Environmental effects

[Anonymous Coward]

It won't matter a damn bit because the earth is still cold all summer long at that depth. If the earth was hot at that temperature it would heat the lake up. The lake can only be marginally hotter than the surounding earth at any point before it loses heat. Thermo...

Re:Environmental effects

[black mariah]

Something you have to keep in mind is that we're talking about a lake with nearly 400 cubic MILES of water in it. It would take a *LONG* time of pumping millions of gallons per hour (Ontario holds about 430 TRILLION gallons) to even dent the lake, and that's assuming you can somehow stop all water from flowing into it before you start.

I recommend you take a much needed chill pill

[FreeUser]

Even if they are not putting the warmed water back into the lake, the removal of cold water will raise the average temperature of the water (as warmer surface water has more of an impact on the overall lake) and will cause the lake to get warmer. We've done enough (I'm from Toronto) to screw up the environment around this city, we should NOT be doing this!

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:Environmental effects

[budgenator]

The water at the bottom of the lake isn't special.
Wrong the water at the bottom of a lake is very special, especialy water at max density or 4C. This water doesn't mix with the lighter, warmer layers, so any that enters it like dead animal or plant material, sewage from a century ago or farm run off stays there. Because the water is so cold, the natural bacteria that usualy breaks down this stuff , does so either very slowly or not at all.
Cuase this water to mix with upper, warmer layers and the bacteria and algea blooms eventualy dying causing ozygen depletion and a dead zone.

Sure this one system probably will not do squat, but if Enwave makes money once, they'll want money twice. Sooner or later a critical level will be exceeded and there will be ecological damage done.

Re:Convection?

[Emperor Igor]

This is the ying and the yang of every decision. There is a side effect to everything.

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:Environmental effects

[mwood]

Ya know, if the only problem with putting heat into the lake is that winter doesn't take it out fast enough, they could do what I do in my home, with a closed-loop groundwater heat pump: take the heat back out in the winter to *warm* the buildings.

Re:In a related story...

[n0wak]

Canadian Department?
Corona!?

You know nothing of this country, do you?

Re:Environmental effects

[dead sun]

Yes, or we can stop bashing people trying to make technical processes understandable to Joe Schmoe...

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:Changes the Ecosystem no matter what

[Anonymous Coward]

"There is no way that this won't change the ecosystem of the lake."

BZZZZT. I'm sorry, that's incorrect.

Stop having a kneejerk emotion-based reaction and do the math. Then realize that you've probably been an idiot about a lot of things you never bothered to do the math on, and sin no more.

This reminds me of the woman who posted her concerns to Usenet years ago regarding the idea of mining the Moon. She was worried that removing ore from the Moon would reduce the lunar mass sufficiently to change the tides.

Re:Just two questions

[Yaztromo]

Man, I can't believe I'm getting sucked into this moronic, paranoiac debate.

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.

Re:Environmental effects

[quisph]

You see it as hysterical ranting, I see it as healthy skepticism. There's nothing wrong with asking questions, even if they turn out to be inconsequential. If the system is safe and sustainable, questions won't hurt it.

Re:Environmental effects

[Anonym1ty]

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

RTFA!

[Anonymous Coward]

The cold is being extracted from water that will be used for drinking / etc. It's not being pumped back into the lake. They're just doing a heat transfer exercise on water that would have, in the past, given up it's heat in pipes, etc.

God help us if this is the techno-elite. Hours of effort spent reacting to a non-issue.

Re:Environmental effects

[GlassHeart]

You're assuming that the lake is being heated evenly. More likely, the warmer water re-enters the lake at specific points and depths, resulting in a more local (but also more pronounced) effect than you calculated.

Put another way, you might as well say that we can just dump waste into the oceans because it's so big it'll dilute whatever poison we toss in. It doesn't work that way.

Re:Convection?

[JustDisGuy]

But, won't introducing warm water back into the lake add new convection currents that will stir things up, affect the lake's organisms, and add certain cleaning chemicals/pollution?

Erm... RTFA. The water is pumped into the city's potable water supply after heat is transferred into it. Contrary to the project propaganda, the laws of thermodynamics indicate that you can't 'suck the cold' out of anything - you must pump excess heat into the colder material.

Anyway, at worst all it means is that the cold water in the tap won't be quite so cold anymore.

Re:Environmental effects

[curious.corn]

Care to get into an argument with a solid state physicist about the "existance" of Holes in a crystal band?

Re:Environmental effects

[Chuck1318]

What damage it causes in between I do not know, but I do know that it has to be looked at.

I don't know how you can imagine that it hasn't been looked at. The Environmental Assessment was completed and approved in 1998. This technology helps the environment by reducing use of refrigerants, reducing electricity use, and reducing air pollution. The kind of knee-jerk uninformed obstructionism these posts demonstrate harms environmentalism by making it look ridiculous.

Re:I was going to ask about that...

[T-Bills]

Actually, since the Arctic Polar Icecap is floating on the sea, it is an iceberg.

True, but since glaciers also form on land they cannot be considered icebergs, and therefore...

glacier != iceberg

yay Toronto!! Down with BUSH !!

[Anonymous Coward]

What I like about this project is how it has the same effect of taking 8000 or so vehicals off the streets. So much fuel saved!

And that has the effect of pissing off george W bush!

why?

because everything that motherfucker has done as president has directly or indirectly benefitted his oil industry friends.

dubya fought against increasing the average fuel efficiency of vehicals produced for the US market ... the 3mgp increase he fought against would have saved 3 times the oil the US imports from Iraq ... saving far more oil than could ever be produced by raping and pillaging that world heritage park in Alaska.

dubya sued california to force that state to stop increasing its fuel efficiency plans, so that you send more money to his saudi oil friends.

when dubya announced his hydrogen economy plan, the same bill silently spent 5 times more money on subsidies for the oil industry.

And that Iraq thing ... which only a blind dumbass piece of shit fool ever thought was about terrorism ... Thanks to Dubyafucker destroying the relative stability that was there, huge uncertainties have been created in the oil markets, more than doubling the price of oil over the last couple years! just LAST MONTH ALONE you damn americans sent $190BILLION dollars to the middle east buying oil. HALF of that money could have stayed in your pockets, out of the hands of the saudis. ... out of the hands of the Bin Laden family that has a huge involvement in middle east oil.

but of course the Bin Laden family gave the Bush family $1.4billion dollars over the last couple decades, buying favour with the powerful american family who has been very happy to respond by sending your brothers and sisters to their deaths to get the oil price up ... paying back the gift a thousand times over.

And that's just oil, lets not forget how right after the election, the electricity shortage in california started, and didn't end until the republicans had won the senate. This 'shortage' has since been revealed to have been totally false, artificially created by friends of the Bush family in the energy industry who intentionally shut down powerplants to reduce supply, to more than double electricity prices. The friends of Bush stole $30 BILLION from the american public through this scam .. and $100Million from the Province of British Columbia, Canada, who tried to ease the shortage by selling more electricity to California ..WHO NEVER PAID THE DAMN BILL, taking money out of MY pocket!!!

in conclusion ...

YAY Toronto! anything that reduces energy consumption, that in effect fights against the most corrupt piece of shit president the USA has ever had is a very very good thing.