Comment by ghshephard | Hacker News Reader

Comment by ghshephard | Hacker News Reader

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"Discharging heat into nature is considered pollution by many countries by now" - Citation please. I'm not doubting you, this is just the first I've heard that discharging heat into nature is considered "pollution.", and I'd be interested to hear the context. I suspect it's in rare scenarios where the water it's being discharged into has a limited heat sink (small lake/river?) Regardless, I find it highly dubious that discharging heat _from a data center into an ocean_ is considered pollution by any country in the world. And I'm willing to wager no country in the world charges hefty pollution taxes for doing so. In fact, I'd be surprised if anyone, ever, has been charged pollution taxes for discharging heat into the ocean. The ocean is pretty big. The United States, in an entire year, uses enough energy to only equal 1% of what the Sun does every day in terms of heat loading.

From: http://en.wikipedia.org/wiki/Solar_energy#Energy_from_the_Su...

"The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year."

1/365 of 3,850,000 exajoules = approx 10,000 exajoules.

From: http://en.wikipedia.org/wiki/Joule, " Energy in the United States used per year is roughly 105 EJ."

In the US, the Clean Water Act covers thermal pollution (well, "thermal discharges"), and based on the language it looks like the provisions have been present since 1972. http://www.law.cornell.edu/uscode/33/1326.html

Actually I'm a bit surprised this isn't that well known with the recent focus on nuclear power, since thermal pollution and cooling system intakes that kill fish have been a minor source of controversy for some plants, including Indian Point and Vermont Yankee. Recent news on the latter: http://vermont4evolution.wordpress.com/2011/04/07/anr-to-rev...

And just for convenience here are the first few results off Google for thermal pollution:

http://en.wikipedia.org/wiki/Thermal_pollution

http://www.pollutionissues.com/Te-Un/Thermal-Pollution.html

http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Environment...

Thanks - I think it's important to note that the citations you mentioned don't treat the discharge as "Pollution", per se, but instead discuss what the impacts of the discharge is. That is, there's no limit on what you can discharge (as there is with pollution), but instead a limitation on the damage you can do to the local ecosystem.

I'd be interested in knowing if any country has adapted statutes with regards to treating thermal discharges as pollutants that need to be regulated. I'm guessing, based mostly on the pre-existing scale of heat loading from the sun, that thermal discharges are not considered to be a pollutant by any country, and you are free to discharge as much of it as you want, just as long as you don't damage the fish/shellfish/wildlife in the area. This also suggests if there are no fish/shellfish/wildlife in your discharge area, you are free to discharge as much as you want.

The EPA defines "pollutant" for the purposes of the Clean Water Act as:

Pollutant means dredged spoil, solid waste, incinerator residue, filter backwash, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials... heat... 14 C.F.R. § 122.2 (definition of "pollutant").

EPA discharge permits, which are required to discharge any pollutant in any amount into US waters, certainly do regulate thermal discharges.

not treated as a pollutant but NZ runs a 'consenting' regime and one of them is to do with the power station (huntley) on one of the main rivers (the waikato) - it is only allowed to operate so as to maintain a temperature window on the river. this is complicated by the fact that the river flowrate (hence volume) is bounded by a consent with a different company that operates the hydroelectric system...

Not a link, but I do know that discharging a bunch of hot water into a stream that is typically cold can wreak havoc with the local fishies that might be adapted to a certain environmental regime.

Like anything, though, a little bit of dumping is just fine, it's when we scale to the size of human civilization that it becomes a problem.

I'd be surprised if places with active geothermal vents would even notice the human induced heating. In that case Iceland seems like an excellent choice. The main problem is when it comes to active fisheries being located near the effluence.

Another thing you can do is to simply use the slightly warmer water like you would use cold water. Half of downtown Toronto's office towers (including 151 Front) are cooled with water from Lake Ontario that then enters the city's water supply.

Just as Cornell U uses the water from Cayuga Lake. Pretty cool :)

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