The Green Penguin: Your Ideas on Heat Recycling

Recently I asked you for ideas on creative recycling of waste server heat. The inspiration came from a University of Notre Dame project that warms a botanical garden with waste heat. This edition of The Green Penguin covers your own creative ideas.

This idea came from Lorenz in Germany:

“We use our Servers to heat the IT-staff-offices in winter (direct linking of the heating system and the server-room).”

Because I saw in Lorenz's signature that he works for a public agency in Germany, I asked him what his agency's policy is regarding the implementation of creative policies like this. He responded as follows”

“We have a suggestion scheme for all these kinds of concerns. The federal and the regional government have different initiatives, projects and activities to put good ideas and concepts to [aid] the mass of the citizens and to reduces costs and [carbon] emissions.”

Paul Brenner at the University of Notre Dame's Center for Research Computing contacted me with a report that introduces a new grid heating framework that removes cooling expenditures and provides dynamic distributed heating benefits to computing facilities. The idea is to integrate computing facilities with other facilities that can utilize the “thermal byproduct the computation delivers”, rather than thinking about the computing facility in isolation.

Brenner's fascinating report can be accessed here.

Meanwhile, Paul in Australia had more general ideas.

I read your story about the Notre Dame university's project of using their server farm's waste heat to keep the desert plants alive. It is a fantastic idea but not one that's new - I've heard of towns in Sweden and suburbs in British towns that are heated by water pumped from the cooling units of local power stations. Here in Australia, a company I worked for in Brisbane [...] ran a small power station in Berwick, Victoria off landfill gas, and the waste heat was used to heat a hydroponic rose garden.  So heating things like swimming pools, greenhouses, drying systems and living spaces during winter is an ideal use for waste heat.

Wes from an unknown corner of cyberspace wrote:

[Here is a] simple idea, perhaps problematic in implementation.

Trap heat from servers in some kind of duct, proportioned in such a way that rising air, eventually cooling, is still pushed out of the vent through a turbine.  The turbine is rotated and through some mechanics produces electricity, perhaps minuscule comparison to what is spent in warming the air but over the course of time if implemented on a large scale the energy spent in warming the air could be offset by the energy produced by the turbine/generator. Or the energy produced by the generator could re-charge/charge UPS batteries in the event of a power outage.

Meanwhile, Kim from Denmark had this to say:

I do not have any particular success stories about waste heat recycling, but as I'm on the fringe of the business, [so] maybe I can give a small bit of input?

Waste heat is - generally spoken - carbon dioxide already used. So every bit of it ought to be recycled.

The simplest way of doing this is to install a air/water heat pump. We had one in the basement for years, it works absolutely nice. A unit the size of a standard fridge delivers hot water to four families. It sucks in hot air, cools it somewhat down and blows it back out again. The principle of air conditioning. Instead of dumping the heat in a radiator outside, it dumps it in a hot water tank.
The pump uses a bit of electricity, but you get about four times the energy out, that you put in. And you get your servers cooled.

On a larger scale, it can be used for heating a building.

A more futuristic way is to use thermocouplers. When you expose them to a temperature difference, they produce a DC current. This could feed the product I work with, a grid-coupled power inverter. Same kind as we use for solar panels. The only snag: the couplers are damn expensive.

As power used equals carbon dioxide used, a even better option is energy efficiency. I don't need cooling of my servers: they run on relatively small machines with C7 CPU's, running various Linux flavors. This is of course not always possible (well, the Linux bit is), but it's a good idea to use a energy-optimized server - and run it down in speed/power consumption, if it isn't under full load.

And last but not least, Michael from yet another sector of cyberspace added:

This [i.e. heat recycling] is a subject that has interested me for some time. I do not understand why manufacturers have not utilized existing technologies such as thermocouples to convert waste heat back into electrical power to feed back into the servers themselves. By doing this, the servers will become more efficient, the more they start to work.

Having done a little research on the Web just recently it would seem that research is being done in converting heat into sound and using miniature thermo-acoustic refrigeration devices to cool equipment such as computers.

I still do not understand why we do not have hardware in place that convert heat for reuse within equipment!

Clearly as mandates grow for firms to reduce everything from costs to power consumption and carbon emissions, the need to examine every ounce of waste will continue to grow. As illustrated by Lorenz's internal heating example above, sometimes a fully internal solution can be found. However, perhaps more likely is a partnership solution, such as the original Notre Dame example that places servers inside the botanical garden, which is in a different location. All of us have busy, focused lives, which makes discovering and exploiting external partnerships challenging. Despite being challenging, the rewards can often be great. The University of Notre Dame's project is saving the university $100,000 per year and the City of South Bend, owner of the botanical garden, $70,000. That's a nice bunch of cash for both partners, and not just in tough economic times.

Perhaps even more promising for the long-term is the systemic thinking espoused in Paul Brenner's report above on integrating facilities. Institutions and governments need to start thinking about how their various parts can interact more efficiently to the benefit of the whole. As the famous environmental thinker William McDonough says, “Waste is food”. One entity's byproduct can nearly always be converted to a resource for another entity.
Harnessing these ideas easily gets you excited and motivated, don't they?

If you have further thoughts or example, please send them to the Green Penguin at . Your input is always appreciated.

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