How to convert excess data center heat into electricity

Here's a gift for the data center who has everything - a thermoelectric generator.

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Credit: Alphabet Energy

While Alphabet Energy’s thermoelectric generator (TEG) is really designed for out-of-the way mining and oil and gas extraction industrial applications, with a bit of adaptation, the idea should be equally valid for our purposes—the heat-creating data center.

The concept is that you capture waste heat and then create electricity with that heat using a simple, long-known of process which absorbs hot air and converts it to electricity using special metals.

California-based Alphabet Energy reckons it has created a highly efficient thermoelectric material that can be produced cheaply. Until now, thermoelectric generation products, on an industrial scale, have been prohibitively expensive to produce.

Its generator, called the E1, is 20 times bigger than anything like it that’s been done before. And it comes in its own shipping container.

How does it work?

Thermoelectric generators work on the principal that heat passed between two dissimilar conductors induces a voltage. In other words, voltage happens when heat moves electrons from the hot side of a bimetallic thermoelectric substance to the cold side.

It’s a kind of electromotive force. It’s called the Seebeck effect, or the Peltier effect, named after two scientists who, separately, worked on the tech in the 1800s.

Problems

One problem has always been that it’s hard to keep the cold bit cold—the heat permeates over to it, which interrupts the process. If the electrons don’t keep moving, they won’t create the electricity. The electrons won’t keep moving if the part that’s supposed to be cold gets hot. This is a materials issue, really.

Other problems include low efficiency in relation to cost.

Alphabet Energy says that it has made advancements with silicon and tetrahedrite that it says lets it create highly efficient thermoelectric materials that come from plentiful resources, which should make it cheaper.

Advantages

One of the reasons engineers have been so gung-ho on attempting to overcome the limitations of the Seebeck effect for commercial electricity generation is that it’s a solid state technology. There aren’t any moving parts to break, or that need lubricating. So it’s an attractive proposition for remote applications, where it’s hard to get maintenance done.

That’s probably why Alphabet Energy has been focusing on mining and oil extraction as verticals.

Space probes and unmanned sites have used variants of thermoelectric generation. Canadian company Global Thermoelectric produces remote power solutions using TEG technology powered by gas. It also pitches itself at oil and gas pipelines and off-shore platforms.

Cooking to make electricity

I’ve written in the past about a camping cooking pot, the PowerPot X, which turns cooking heat into device-charging power using Seebeck technology. It has an advantage over portable photovoltaic solar panels, also good for remote applications, in that you can charge portable devices, like GPS devices, at night—while cooking. The idea being that you’re more likely to be back at camp, performing chores at night when it’s dark. Solar panels don’t work in the dark, obviously.

The PowerPot X, a 10-Watt cooking generator, might be a more economical way to play around with the technology than a fully fledged, container-sized, mine-capable generator, like the Alphabet E1.

The PowerPot will be $199 when it’s released—not until spring 2015, though. So, if you’re looking for a Seebeck technology present for your data center this holiday season, you’re going to have to go for the container-sized E1 option. Happy Holidays.

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