Recycling Excess Heat From the Data Center 121
itwbennett writes "A new data center being built in Helsinki, scheduled to go live at the end of January, will generate energy and deliver hot water for the city. The data center is located in an old bomb shelter and is connected to the Helsinki public energy company's district heating system, which works by pumping boiling water through a system of pipes to households in Helsinki. The recycled heat from the data center could add about 1 percent to the total energy generated by the energy company's system in the summer." The article doesn't say what the overall efficiency of the heat recovery is. Researchers at MIT are working on a new energy-conversion technology based on quantum dots that they say has already demonstrated 40% of the Carnot efficiency limit — 4 times what is achieved by current commercial thermoelectric devices. The researchers believe they can reach 90% of the Carnot limit.
WTF, why is a Carnot reference here? (Score:4, Insightful)
Re:WTF, why is a Carnot reference here? (Score:4, Informative)
How is the Carnot cycle apply here? This is direct heat conversion, and the efficiency should be near 100%, you would have line losses.
Reading thru a filter of journalist ignorance, I think the journalist is trying to say they're using a heat pump to reject the heat from the cooling system into the heating system's boiling water. There is a Carnot cycle limit to heat pumps.
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Re:WTF, why is a Carnot reference here? (Score:5, Informative)
because the summary is talking about two entirely separate topics. (1) Helsinki data center will deliver waste heat in useful form to the city. (2)Researchers at MIT are working on a solid state heat-to-electric conversion element called a thermoelectric device. current devices are at best ~10% of Carnot (practical devices approach 10% total efficiency on a good day), and they say they'll hit 40-90% of carnot with their new quantum dot TEG's. We'll see.
You are correct, though. Carnot efficiency discussion only really applies to (2) not (1). Mister itwbennett just decided to lump these two things into one submission.
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You can shorten the line to as much as you want. Assume no energy is lost to
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I put electricity into a chip. The chip uses X amount of energy and ~100% of the (electrical) energy is converted to heat energy.
If I run water over the chips (lets assume fully submerged for simplicity) and maintain their temperature at 20 degC. ~100% of the heat is removed by the water.
I realize there are line losses in the electrical wires. There are he
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And this is exactly why heat pumps are not rated by efficiency but by coefficient of performance (COP).
Of course nobody seems to have noticed that the 40% claim is completely unrelated to the headline story and seems to have been needlessly tacked on by the editor.
=Smidge=
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Carnot cycles are for calculating heat engines. This is not a heat engine. There is NO WORK being done.
First of all theoretical efficiency limits apply to both types of reversible heat engines- steam engines which extract work and heat pumps (e.g. air conditioners) which require it. (In the heat pump case I guess Th would still be a temperature in the datacenter somewhere, but Tc would now be
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You design a cooling loop of water that cools the data center. You pump water fast enough to remove the amount of heat generated by the data center, and maintain a certain liquid temperature, which will translate to a certain chip temperature.
This water say enters the data center at 20C and leaves at 50C, you can change the temperatures of these by adjusting the flow rate of water (assuming a const
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(But psst... there is no "d" in "refrigerant".)
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Or make it much simpler - city heating systems need a water inlet to compensate for lost water in lines and for hot water usage by the people. Instead of taking cold water (at 20C) from the cold water system, the water is first piped trough a data center where it get heated up to 50C, so the city heating system needs less heat to heat this water to the 95C it uses in its circulation. That's it - simple and almost 100% efficient.
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You know way too much about computers.
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The Swedes have an advantage being so far North, but if they were to move their datacenter inside the Large Hadron Collider- or if they were to move the population of Sweden into the datacenter- your post would have more merit.
Sweden? Last time I checked, Helsinki was still in Finland. And no. We Finns wouldn't like the idea of 9.3 million more Swedes in Helsinki.
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Yeah I read too fast. Although when I was a kid I used to have a Finnish pen pal in Turku. She stopped writing.
No wonder she stopped writing if you thought that Helsinki is in Sweden. We do have a hate / love relationship with the Swedes.
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I just did the same thing for my caravan
to help out the aircon.
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Yes. Where do you think the energy goes? The first law of thermodynamics requires that you get it all back.
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Not much of the power leaves the actual datacenter building. If you think about it, the only useful energy leaving the datacenter is a few volts in the Ethernet cable or a bunch of photons the the optical data line. The rest of the electricity that the datacenter uses is convereted into heat each time a memory cell is reset to the resting state via the flush resistor and such.
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I think it's great, but... (Score:4, Insightful)
Is pumping boiling water through pipes the most efficient way to heat houses? Isn't there a pretty massive heat loss in the pipes?
Having said that, if they are already using this system for heat, the introduction of waste heat from a datacenter seems to make a lot of sense. Acts as a heat sink for the data center, reduces the amount of energy needed to heat the water.
It works well in cities. (Score:2)
Sure, you do get some loss but the simplicity and reliability of these system is quite impressive. I suppose they could always get extra-big pipe wrap :)
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Well, they have to be, because you're basically threading a steam bomb [google.com] throughout your entire house. I'll stick with forced air thank you.
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Ew, forced air? What a pain that is. I'm all about radiant hot water heat these days. You don't have to worry about mold and pathogens in your ductwork.
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I'm all about radiant hot water heat these days. You don't have to worry about mold
Until it starts leaking. Then you have cold, and mold.
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Well the baseboard heaters in my 60-year-old home haven't leaked yet...so I'm not so concerned about that issue. Maybe the modern under-floor systems are prone to leakage, but the tech I have seems bullet-proof. If you need AC then forced air is your only hope...but we are cool with a well-shaded lot and a window unit or two.
Forced air is too dry (Score:4, Informative)
Forced air will dry you into a raisin. It is December — do you notice, how dry your lips are in the morning?
You need humidifiers to fight that effect... No, hot water — pumped through fixtures made of cast iron, or something, that's even slower to warm up and cool down — is the best heating solution... It could be expensive, but it is the most comfortable of what's commonly available today.
The oft-used copper and/or aluminum fixtures are bad, because the temperature will be fluctuating widely between the times, the heat is turned on by your thermostat and the times, when it is off. Our bodies are more sensitive to changes in temperatures, than to the temperatures themselves. Also, a quickly-heating material ends up losing heat mostly through convection (heating up air, that rises to the ceiling), than through radiation, which warms you directly (via infra-red).
Stainless steel is better in that regard than copper/aluminum, but not as good as cast iron, heavy and "unattractive" as those things might be...
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Seriously, though informative, it was painful to read.
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Stainless steel is better in that regard than copper/aluminum, but not as good as cast iron, heavy and "unattractive" as those things might be...
I happen to love the look of cast iron. I recently had trouble buying a cast iron dutch oven because most of those available in retail are coated in enamel. Although this is popular, I prefer the rustic look of the cast iron.
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I'm sorry but I'm going to have to call bullshit on your comment. You implied that running hot water through cast iron radiators will result in a comfortable house but using a forced air system (let's say it uses natural gas) dries out your lips. Please provide some details, math and/or science to back up your claim. If you use hot water to heat the house to 70 degrees, how can the rel
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Simple... You'll be moving air. And by doing so you'll be subject to the same effects, as the clothes drying in the wind. You want to be warmed up through infra-red radiation as much as possible, with the minimum convection component, because convection moves air (hot rises up).
It also makes for uncomfortable differences in temperature between floor and ceiling — you may feel chill in your legs (or your toddler may be cold), but
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Well, most of the 'hot' or 'cold' feeling actually comes from your feet. So it does not matter much what you breathe in (within a few degrees) as long as your feet are warm. That is why floor heating systems are the most economical, because you can comfortably maintain much lower temperatures.
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"Forced air will dry you into a raisin. It is December — do you notice, how dry your lips are in the morning? "
Nope but then I live in Florida.
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It is hard to see how maximum 35 degree C water (with 1 bar pressure) could be steam bomb. That is the water temperature I have running inside floors. Even if water coming into heat exchanger may some times exceed 100 C, and you can get seriously injured if you are close to pipe break, I prefer it much to system having flame and exploding gas.
Most of time the heat is by-product of electric power plant, so distributed heating is a good way to improve overall efficiency.
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Most heating systems never reach the boiling point. The working temperature is between 60C and 90C. Noone wants to deal with steam.
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The main benifit is that you can easily recover waste heat. From power plants, or any other large heat source.
And with proper insulation you can limit your heat losses.
Re:I think it's great, but... (Score:5, Informative)
Is pumping boiling water through pipes the most efficient way to heat houses? Isn't there a pretty massive heat loss in the pipes?
Having said that, if they are already using this system for heat, the introduction of waste heat from a datacenter seems to make a lot of sense. Acts as a heat sink for the data center, reduces the amount of energy needed to heat the water.
Actually, it's a reasonable system for heating large building complexes where a central facility can heat the water. Many Universities and large corporate complexes already use similar methods for heating their campuses. Insulation on the pipes keeps the water warm in transit. These complexes can also cool their buildings in the summer by pumping chilled water through the system.
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'Already' is a bit misleading however - central heating installations like these, using steam or hot water, go back over a century - New York's dates from 1880.
Or they can
Re:I think it's great, but... (Score:5, Insightful)
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Its not the most efficient way, but often it is the most practical and economical.
Also, if the pipe breaks, then its not really that bad of a cleanup.
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It's fairly common in Northern Europe (excepting England, for some reason). Losses aren't very high because the pipes are insulated. In modern systems the water isn't boiling, but it will take a long time before everything has been converted to lower temperature systems.
You can get extremely efficient by using low-temperature (30C or lower) remote heating plus a heat pump, but that means a large investment per house or apartment block.
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Not to say that lower-temp systems don't exist (I can see the appeal in single-building residential systems in particular), but I'd point out that virtually all non-residential heating loops don't actually carry water they carry steam (at least on the efferent lines). They do so for the simple reason that steam-at-100C carries 3-5x the energy of water-at-100C (dependin
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but I'd point out that virtually all non-residential heating loops don't actually carry water they carry steam
Not around here (Denmark) they don't. Steam used to be popular, but it's a waste of energy which could be used to make electricity.
But as I said, not everything has been converted yet.
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Not in Eastern Europe - all ex-soviet systems are hot water based without any steam.
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What do you mean "excepting England" - almost all houses here have central heating based on water-filled radiators. I'm having to think very hard about the last house I visited here that *didn't* have a piped water heating system.
The water isn't usually boiling though, since the systems are almost always open circuit (so not pressurised). The one in my house uses water at about 60C, and also provides hot water for the tank for showers/dishes etc. I don't have a combi, so if you want hot water, you have to s
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I well understood the summary (and the FA), but "sending hot water around liquid filled radiators" is a very popular method of heating your home in England, centralised distribution or not.
There are examples of centralised distribution here - mostly pilot projects, since the infrastructure for houses is already here and well understood - ie, liquid pipes and metal radiators, so conversion to centralised systems is simplified.
It's really much easier if you don't misinterpret what I say and apply your own me
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Ok, from the original post:
Is pumping boiling water through pipes the most efficient way to heat houses? Isn't there a pretty massive heat loss in the pipes?
I think it's obvious that the original poster meant remote heating. The original article is about remote heating. I was certainly talking about remote heating.
You're the only one who is talking about how to get heat transported around inside the house.
England is stuck with a lot of antiquated systems where electricity is turned into heat without a heat pump. You pretty much can't do worse than that, thermodynamically.
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I've never seen a normal house with district heating in England, only university campuses (and presumably similarly structured settlements, like hospitals). Wikipedia says "Though they are said to be efficient, a frequent complaint of residents is that the heating levels are often set too high - the original designs did not allow for individual users to have their own thermostats." -- that's something I've heard before, and would fit with English people deciding they don't like something and rejecting it ra
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[District heating is] fairly common in Northern Europe (excepting England, for some reason).
It's usually used for industrial purposes in England rather than domestic or commercial. Part of this is due to the fact that large power plants tend to be located well outside cities (as an anti-pollution measure and because land values out in the boonies are lower).
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True, you need the power plants fairly close to the consumers, which can be a problem. Especially in England with plenty of rivers for cooling, so the power plants haven't been forced to be placed where people live.
It IS great (Score:3, Informative)
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Usually, district heating uses waste heat from power plants. It'll be wasted anyway, so why not use it to heat houses?
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However, the cost of installing these systems is often costly. Since pipes obviously cost much more than water. For a good example we can look on a smaller scale. Many houses and buildings built 50+ years ago had cast iron radiators. We don't use them anymore because they are expensive as fuck to install and maintenance is more expensive. But overall efficiency is similar and in some cases better than present day systems.
So I would guess it is a system already in place f
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It depends on the priorities and the source of the heat. Steam turbines have a considerable load of waste heat that has to be dumped somewhere. No sense heating a lake if it can heat homes instead. Since it is waste heat, the efficiency hardly matters, any usefulness beats the alternative.
In other cases the choice is between many small boilers or one big one with exhaust scrubbers and more complete combustion. With good pipe insulation that can be a win.
It's much much much more efficient (Score:2)
Is pumping boiling water through pipes the most efficient way to heat houses?
Yes. Easily. The pipes in district heating systems are heavily insulated, and large.
http://www.exakm.gr/images/Transmission%20pipe%20installation.jpg [exakm.gr]
1. It's WAY better than burning fuel to create electricity to transmit to the houses to create heat.
2. It's substantially better than pumping gas out to millions of tiny water boilers which do nothing but heat water.
3. it's "waste". The bit most power companies throw away after generating electricity. Anything you get from it is essentially "free".
You can turn
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Quoting Wikipedia [wikipedia.org]: "Warm water U
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A (very) large portion of Manhattan is heated via a central steam system. It's incredibly efficient, and is also the reason why almost no NYC buildings have noticeable smokestacks, and why the city was actually quite clean until the rise of the automobile. By concentrating the coal burning into a few points (5 IIRC), pollution in the city was greatly reduced.
On a somewhat more scary note, thanks to decades of neglect, many of the original pipes are still in use, carrying high-pressure steam. Failures are
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Naturally there will always be energy loss when you tranport energy.
But this system is pretty well suited for cities. And naturally the pipes are well insulated and laid under ground to keep ambient temperature constant.
The water is heated at the plant (or the data center in this case) then pumped to the system. The system consists of main lines usually running under streets. These have smaller lines going to a connected building. Inside the building the pipes go to a "boiler room" or heat center or what-ev
The problem with approaching Carnot efficiency... (Score:1)
Re:The problem with approaching Carnot efficiency. (Score:2)
the process will take longer and longer time
Well, but in a flow reactor, that won't matter. It might take an ounce of water a long time to go through whatever this system is, but once it's flowing, it does not matter how much time it takes. Flow in == flow out, presumably. It will seem instantaneous after the startup time.
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"Heat engine" != direct thermoelectric conversion (whether via quantum dots or just plain ol' Peltier junctions).
The Carnot limit simply doesn't apply to direct conversion, and AFAIK, no theoretical limit to near-100% efficiency (minus entropy) exists for the latter.
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The Carnot limit applies to any heat engine, no matter how it works. Heat -> work means no efficiency higher than Carnot, sorry. Your "minus entropy" part gives that away really, as that's what's responsible for the Carnot limit in any case. Entropy change of X = heat transferred into X / temperature of X. So taking heat out of something causes an entropy decrease, hence the need for a cold sink to create an entropy increase so the overall entropy change is positive.
Valium and Xanax for Engineers and Physicists (Score:5, Funny)
The pump is also very efficient -- you get five times the amount of energy you put in, he said.
So, engineers and physicists, when you see statements like that, how do you cope:
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It doesn't bother me much, lots of problems from school involved modeling the environment as a magic line.
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6. Post condescending comments on a forum that no one will read.
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6. Drink the tears of Cowboy Neal. Fixed that for ya.
Re:Valium and Xanax for Engineers and Physicists (Score:5, Informative)
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when you see statements like that, how do you cope
Well, you could just try to understand from context, that they mean, five times the energy put into the system besides the energy recovered from the waste heat, which is "free" in this context.
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you could assume he might be talking about coefficient of performance but he doesn't remember the exact right phrase.
more troubling, even if he used the correct phrase, his intended audience probably wouldn't understand him.
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So, engineers and physicists, when you see statements like that, how do you cope:
Easily, because I know that a heat pump [wikipedia.org] is a machine that allows me to move 5X amount of heat from one location to another while only using X amount of energy to do it.
(BTW, if you heat your house using electrical resistive heating, and you have a garden... go look up 'ground source heat pumps' from that article and save yourself lots of money.)
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Heat is not energy*, at least not useful energy. Specifically heat alone is not useful for doing work. You need a heat gradient to do work. Heat pumps increase the heat gradient, and that gradient could be used to do work, but the amount of energy you would get out of that is always less than you put in.
Heat pumps are a rather efficient way to heat your house, within a certain temperature range it can be much more efficient than burning chemical fuels.
*(yeah, heat really is energy, but heat pumps just mo
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Heat is not energy*, at least not useful energy.
FU! Welcome to Finland. I'll let you wait outside [www.fmi.fi], while you reconsider how useful heat is...
Quantum Dots.... (Score:2)
This is what is used to power Matroska brains.....
That's good (Score:5, Funny)
"Honey, why are you watching so many porn streams at once?"
"Because I'm cold!"
Obligatory (Score:3, Funny)
It's a fucking heat pump, people. (Score:1)
It uses cold water from a central plant and then it gets cooled back down by a chiller/heat pump. The condenser water off the heat pump is then used to heat homes. Basically, the plant is rejecting it's heat into the local housing system.
The part about thermoelectric devices is a total non-sequiter.
Central Heating to the extreme (Score:2)
I experienced this to some extent when working in Magnetogorsk, Siberia in '94. The hot water for a lot/all of the town was supplied centrally and piped all over the place in 1m diameter pipes (above ground).
Aside from the efficiency issues due to heat loss from the pipes, the main fun factor in this system was that the distribution was not terribly fine grained. As a result the authorities shut down the hot water for entire sections of the city when they wanted to do extended maintenance - and by that I
Space Heater (Score:2)
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Yeah, I point the case fans at my feet in the winter time!
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What about the exec office? (Score:3, Funny)
Any ideas?
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It's been tried many times, but no matter what you do to it, you just can't get the bullshit smell filtered out.
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Have you tried using corks?
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Quantum Dot (Score:2)
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Heat Recovery [feeddistiller.com] Feed @ Feed Di [feeddistiller.com]
Heat Recovery Ventilation (Score:3, Interesting)
Common commercial devices for homes already use heat exchangers to recover 66% or more of heat from vented air, heating the incoming fresh air with it. During heating seasons, machinery's inefficiency generating heat can replace heat that would have consumed more energy. Bathroom fan vents cost under $300.
What we need is good heat storage devices. If a lot of heat can be stored during the cooling season, and released during the heating season, these electrical devices become close to 100% efficient. Places like Helsinki have much longer heating than cooling seasons, so they're good places for datacenters that can recover heat for use.
The problem is that water is about the densest heat storage material we have, but it doesn't store very much. And even the most cutting edge insulators, aerogels, are only about 2x as insulating as the current common top performers, closed cell foams, and only about 4x as insulating as the earlier common stuff like fiberglass and cellulose. If we could store in similar volume the energy that fuels like oil store in chemical covalent bonds instead in physical materials like high specific heat fluids that don't get that hot, we'd have a lot more options in engineering efficiency. If we could regenerate chemical fuel from heat at very high cycle efficiency, we'd have something of a miracle cure for many of the worst of our industrial ills.
Telehouse West, London (Score:1)
The partnership will see Telehouse West save up to 1,110 tonnes of CO2 emissions per annum and provide up to nine megawatts of power for the local neighbourhood. The energy savings will equate to boiling 3,000 kettles continuously. The disposal of waste heat from cooling systems is one of the most significant sustainability issues associated with data storage. This will be the first time a heat export strategy has been introduced in the UK for this type of data centre facility.
In fact, I seem to recall a discussion about this on here a couple of months ago about yet another project doing the same thing. The consensus was that whilst there was a lot of air pumped out, it wasn't exactly hot & it wasn't useful for much more than good PR for the host - far better efficiencies could have been m
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