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."

Just two questions

[cyclop]

(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.

Messing with lakes: NOT a good idea

[Capt'n Hector]

Several times in recorded history, lakes have "belched" massive amounts of carbon dioxide, killing off not only fish, but people in surrounding areas. Lake Nyos [bris.ac.uk] is one such example. The circumstances vary, but always involve extremely deep water, saturated with CO2, being shifted to a shallower depth. When this happens, water has a much lower capacity for CO2, and it is released into the air.

Not that I'm predicting this will happen here, but it's usually best not to heat deep water like that.

"The cold is extracted"?

[Bertie]

Er, how? What does this mean? Cold's just the absence of heat, the only way to "extract" it is to heat something up.

The lake WILL warm up

[Siderean]

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!

Re:Environmental effects

[black mariah]

And again, I ask, what is going to heat the water? as long as they don't suck out enough water to significantly lower the lake lever in a short amount of time, there is no chance of that happening.

Re:The lake is NOT warming up !

[frovingslosh]

Actually, it's unlikely that the city was drawing it's drinking water from this deep before. They were almost certainly taking it from a point higher up and warmer. So the city drinking water may not be warmer at all as a result of this; it might even be cooler. And, since the lower water can hold more CO2, it might be slightly carbonated! (Look for the interesting side effects when somewhat more acidic carbonated water is flowing through old pipes.)

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:Environmental effects

[goatan]

as it's far better to shut stupid Greenpeace hippies up before they can start their jaw flapping.

Not that it will stop them turning up in a boat that uses copious amounts of fossil fuels [greenpeace.org], whilst protesting the amount of fossil fuel that are used in the world (they fitted sails to rainbow warrior but it's main propulsion is 2 6 cylinder diesels very environmental. or releasing minks from a fur farm on grounds of animal cruelty and they end up devastating the natural wildlife for miles around. [bbc.co.uk]

somehow despite ther intentions greenpeace and there supporters seem better at destroying rather than saving.

Show me the numbers

[Stephen Samuel]

This is one of those things that looks good when you start -- but what happens when everybody starts doing it? What I'd love to see is some info on the volume of water extracted from the lake for this project vs. the volume of water in the lake. This would give geeks like me a much better chance of being able to figure out for ourselves just how much this is going to affect Lake Ontario and how much the basic idea is going to affect the lake as the idea becomes more popular (as I expect it will).

It's a GREAT Lake

[Titusdot Groan]

Just a reminder folks, Lake Ontario is one of the Great Lakes, it's REALLY big. Like you can't see the other side of it from the shore line. Big. Really big. Like it's huge. Average depth of 86 meters, surface area of almost 19000 km2. Big.

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:Just two questions

[bobwoodard]

Valid concern? Everyone is acting as if it doesn't get cold up there? Hello? Even if there is a rise in the tempature in the lake that is measurable, just wait until winter and the whole system will be 'recharged'.

Re:Environmental effects

[L0C0loco]

What??? Water is its densest at a temperature of 4C. Cold water pumped out during the summer cooling months has a chance to be replenished during the next winter. As the winter ice melts and the melt water warms it begins to sink due to the relative increase in density as it approaches a temperature of 4C. So long as the winter cooling capacity of the lake exceeds the summer cooling needs of the city, this should be a sustainable practice. It is true that the thickness of the cold layer will thin during the summer pumping season, but it will thicken again during winter. Obviously, this pumping will cause the mean thickness to decrease - they just need to hope it doesn't thin too much. The problem with free lunches is that people eat too much, get fat, and die!

Re:The lake WILL warm up

[MKalus]

So you think removing the cold water (and last I checked we still have Winters in Toronto so it will cool down again) will be more damaging than pumping all the CO2 into the air by trying to cool conventionally?

Re:Environmental effects

[Anonymous Coward]

Not exactly directly related, but interesting nonetheless so I'll side track a bit.

Here in Tokyo, there's a re-developed area called Shiodome right near Tokyo Bay. There are about 6 sky scrapers (that I can see from my window here in the office, cough cough!) really close to each other that are all roughly 45 stories high. They've all been erected over the last 1 or 2 years, and there's proof that they're heating up Tokyo by a very measurable degree.

First of all, they're blocking the sea wind, and the district directly behind the buildings has had a 50% decrease in average wind speed. The area has also increased in average temperature by about 3 degrees Centigrade, thanks to what they call the heat-island (heated concrete and asphalt covering everything, giving off heat long after the sun has set) and the lack of wind has just helped it. This, as a result, has somehow effected districts as far as 20Km away, apparently. When I first heard this about 3 years ago (there were some professors that were warning that building high buildings in that area was a really really bad idea) I thought it was just some environmentalist hooplah. Well, turns out I was wrong.

One more note is that the wind around here is NOT that strong, nothing compared to Chicago, so it's not really a threat to the buildings themselves.

I still doubt that a few wind turbines would have enough impact on the environment to be noticeable, but then I now know better than to trust my first instincts. Ouch.

Re:Environmental effects

[macthulhu]

I live about 90 miles south of the Canadian border in Western NY... The winter cooling capacity 'round these parts is pretty high. It's about time somebody figured out a way to use the area's largest natural resource... Snow. My only question is what happens to algae growth if the lake warms up even a couple of degrees?

This is happening elsewhere

[samjaffe]

Cornell University recently did this with the deep water of Cayuga Lake (http://www.worldchanging.com/archives/000839.html ). As you can imagine, it caused quite a spirited debate in such a liberal town as Ithaca. In the end it was approved and the University is gauging the environmental effects very carefully(http://www.town.ithaca.ny.us/PEZ%20proje cts/Lake%20Source%20Cooling/lake_source_cooling_mo nitoring_p.htm). So far, there's been little effect. Although some (http://www.cldf.org/tt_981216/chap1.html) might disagree. I would like to point out to the concept's cheerleaders that there's nothing wrong with asking questions about the fundamental ecological effects of our engineering projects. Those questions should be answered thoroughly and carefully. Yes, global warming appears to be a severe problem, however let's not replace it with a bigger problem by stifling debate and rushing in with an ABCO2 (Anything But Carbon diOxide) attitude that might be more harmful than the disease.

Re:Environmental effects

[gowen]

YIAAEE (Yes I Am An Environmental Engineer)

Cool. I'm an environmental fluid dynamicist. Here's one for you. I saw a talk about this recently, concerning coolant water from a nuclear power station.

Take a lake at about 3C, and inject some water at about 10 degrees. You get a surface gravity current, that steadily cools. When it gets to about 5C, its becomes *more* dense than the cooler water beneath it, and the warm water sinks as a plume through the cold water, and you get a stably stratified lake, with a warm water intrusion at the bottom supporting a colder water mass.

Re:5 Tonnes CO2 per Car?!

[the_twisted_pair]

Run the numbers for burning gasoline and you'll find out.

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...

Also an interesting fact about water

[ShadowRage]

and the water will never reach freezing at the bottom, it'll always be a degree or just afew hundreths of a degree above freezing at the least, never lower than that? why? water in its solid form is lighter than its liquid form, it's one of the few elements that does this, which makes its liquid form rare in the universe. However, by utilizing this, they can cool office buildings and never worry about heating up the lake, unless they pumped the warmer water they used to the very bottom, but even then the water would chill, and would get colder again, because the amount of cold water outweighs the warm water.

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:Environmental effects

[SillyNickName4me]

While what you say is true, it in no way changes that the temperature at low levels will rise as a consequence. Explaining how the water gets that cold says absolutely nothign about what happens when you remove it, it only suggests that if you leave it alone long enough, the water at low levels will have cooled down again.

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.

I hate this

[nightsweat]

I don't hate that the Canadians are doing this sort of work, but I do hate that we're not. Look, I'm in Chicago, a huge American city with the slogan "the city that works" and where we decided that the river flowed the wrong way, so we changed it. Why the hell aren't we putting in something like this?

These days those quasi-socialists have it all over us...

Re:It's a GREAT Lake

[Anonymous Coward]

Thanks (really) for stating what should be obvious. There are more than a few coastal types (especially in California) that think Lake Michigan is about the same size as Lake Tahoe (or maybe smaller). "Whaddya mean you can't see across it?!" It's part of the Cali-centric mindset, I guess.

A normal air conditioning system is worse

[gotan]

The usual Air conditioning System uses a heatpump and needs electricity to cool the air (just like a refridgerator). That electricity ends up as heat (outside) as well. So looking at totals it's more efficient to use cold water from the lake for cooling (if available) than to use heat exchangers that run on electricity that just ends up as more heat *and* has to be produced by a powerplant producing even more excess heat.

The concern where the excess heat ends up is valid though, but apparently they use it to warm up drinking water that would've been taken from the lake anyway.

As a pedestrian I welcome this

[geoswan]

There is one advantage of this system that I haven't seen mentioned yet.

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:Geothermal Heat Pump

[yabos]

It's not only the ground water, but even the ground soil below the frost line remains at almost the exact same temp year round.

I'd post my dad's(who is a Geothermal tech., installs them for a living) website but I don't want to make him burn through his monthly GB limit in an hour.

He has installed a Geothermal heatpump in a house that was previously using electric radiators for heating and only heating half the house to barely comfortable temps. for the winter. The person is now paying less than half the cost of electricity, all the while heating his entire house to 75F.

Residential applications?

[swb]

I've always wondered why you couldn't use a similar system in a residential area. We have a lake behind our house that's about a mile around and about 8 feet deep on average; couldn't we (at least the immediate lakeshore residents, if not a larger amount of neighbors) use the lake water to augment our air conditioners?

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:Environmental effects

[SillyNickName4me]

The problem is not so much that you remove water (tho it has to come from somewhere in the end) but that you change the temperature distribution of the water.

If this is a problem or not should be properly investiugated. The consequences of it could be none at all, or way beyond what anyone would expect.. or anywhere inbetween.

It is a bit like the weather.. an completely insignificant event at one place can be the cause of a very dramatic event at some other place.

when I was living in Toronto

[WormholeFiend]

the hot summer days were pretty harsh, and talk about electricity peak demand due to air conditioners was constant.

so I wondered, why cant the government enact a law that forces every house owner to put solar panels on his roof to help power his/her air conditioner(s)?

it might not be efficient for other applications, but the hottest days are when there are no clouds in the sky, so the solar panels would work best when they are most needed.

granted this has nothing to do with Lake Ontario's cold water, but that solution was thought up due to the strain on the electrical grid... and this is what my idea was all about.

Re:Convection?

[berzerke]

...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".

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.

Re:Is Chicago out of luck?

[geoswan]

That's not true at all.

That is interesting. Maybe Baldwin isn't only a fan, but he is also plans to be an developer of this technology for profit? Maybe he was already an investor in en-wave?

Before I was paying full attention the interviewer asked him why this technology was being developed in Toronto first. He made some flattering noises about the co-operation between foresightful Toronto politicians and foresightful Toronto real-estate and property management types.

Maybe there are legal or administrative reasons that prevent the widespread adoption of deep lake water cooling in Chicago?

There are large buildings that could have signed on board this system, and chose not to. Here in Ontario large users of electricity pay a much lower rate than ordinary consumers. One of the documentaries I saw about this system, a year or so ago, quoted an energy conservation expert who said that if large commercial users had to pay the same rate for their electricity as ordinary consumers they would start to take energy conservation more seriously.

Does Northwestern University have its own private water system for some reason? If you find that link, please post it. Thanks.

Re:Environmental effects

[Doc Ruby]

If we posted two, you'd complain there's only two. You're batshit crazy. Too bad we have to save your skin along with our environment.

Re:Environmental effects

[pilgrim23]

200 yers ago men with horse buckboards and hacksaws went out on the lake, cut up massive blocks of ice, hauled these back to underground brick lined cellars and packed them in straw. All summer this ice was used to cool those who could afford it. This pumping tech just strikes me as an extension of the earlier tech.

Re:As a pedestrian I welcome this

[WindBourne]

Interestingly enough, most large buildings do run AC during the winter. Add up all the heat from ppl, computers, lights, etc. and the fact that buildings are better insulated than 50 years ago, you will see that you have to pump heat out (at least during the day). Bizarre though, huh.

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.

Here's another idea

[Rui del-Negro]

How about writing an e-mail to the article's author, explaining his mistake? I just did that, and in 5 minutes he corrected the article [theglobeandmail.com]. It now says:

"Brought to the John St. Pumping Station, the lake water is used to cool down other water that will then be used to lower the temperature in downtown buildings."

There. I would probably have mentioned something about "heat exchange", but the current version is not too scary for Joe Below Average and is technically correct.

RMN
~~~

How long will it take to pay back?

[Anonymous Coward]

I live in Toronto, and I know that the electricity rate is about 5.5 cents per kWh for businesses. The rate is determined by the Ontario goverment's Ontario Hydro Corporation. It is expected that the rate will go up within a year, but let's estimate 5.5 cents for now.

The CEO's bio, say it cost CDN$175 million to do the project. For the rough estimate, let's assume that it is operating at peak capacity, which it isn't yet. Another assumption is that it is used four months of the year. At a power of 59 MW, it would displace $9.3 million of electricity generation. That would take over 19 years to pay back.

I would imagine there would be a cost for maintenance. However, they may be able to make some profit during cooler months, since as one poster has pointed out, some modern office buildings trap heat in the winter and need air conditioning to compensate for heat sources such as people, lights, and electronics. I don't know what kind of demand that would necessitate.

With such a long payback time, that may be one reason why we don't see more of them. It's exactly the kind of thing the federal government should be investing in instead of Petro Canada (a Canadian oil and gas company.) FWIW, the NDP had a campaign platform to sell off the PC shares for investment in energy efficiency and green technologies like this in the last election: http://www.ndp.ca/ftp/platform/en/greenfound.php [www.ndp.ca]