Until about a decade ago, thermal energy was considered almost entirely as an analog, bulk phenomena. Regardless of whether the heat flux was conducted or radiated, the flux was related to the temperature difference between a hot object and a colder environment. Convective heat transfer was simply a physical result that many things become less dense when heated at constant pressure; therefore in liquid or gas systems, due to gravity, a bulk material flow could be established by conducting heat into a cooler fluid thereby making it buoyant. Not that heat transfer problems are simple to solve in the real world, but the underlying physics has been understood for a long time. In many cases complex systems can be adequately analyzed using lumped models of thermal resistances.
Things began to change when heat flux was successfully described as the movement of phonons. In 2006 researchers at the University of California, Berkeley, demonstrated a form of thermal diode, in which heat flux in one direction could be controlled to be higher than the other direction along a carbon nanotube. Recently, researchers at the Charles Fabry Laboratory in France and the Carl von Ossietzky University in Germany showed a thermal transistor that can operate using radiated thermal energy (photons instead of phonons). It has been suggested previously that such devices could eventually work as logic gates in MEMS (Micro electro-mechanical systems) devices.
These non-linear thermal systems are an exciting area of development, but most of what we are concerned about in electronic systems, whether analog, digital, or mixed signal, is what to do with the heat generated the old-fashioned way by various dissipative processes in the chips and passive components that make up useful electronic systems. A company in The Netherlands called Nerdalize is offering a unique solution that combines distributed cloud computing, utilities, and home owners in need of heat to keep their homes warm. (Note: Although the word “nerd” appears in the Dutch language, I'm not clear if it has the same meaning in The Netherlands as in the US, thus I don't know if the company name is an obvious pun or just a name.)
What Nerdalize does is install a high-performance computing box in a home, connect it to the internet via a high-speed link, then sell the compute power to their cloud customers. As payment for hosting the box, which Nerdalize calls a heater, Nerdalize reimburses the home owner for all the electrical energy used, thereby making the heat generated (and used to warm the home) “free”.
On their website, Nerdalize claims they offer cloud compute with a cost per job up to 55% lower than other providers. Presumably this is because they don't build dedicated server farms, reducing their capital costs. I reached out to the company with a few questions. In particular, I asked if they needed dedicated high-speed links to each box to make the system work. They responded in an email with “We prefer homes with fiber which [are] abundantly available in The Netherlands.” That resonated with me since although CenturyLink is rolling out 1 Gb/sec service in some locations, I'm limited to 7 Mb/sec. I guess that means I won't be getting a heater from Nerdalize anytime soon. (Note: There is no indication as yet that Nerdalize would expand into the US.)
By making the compute nodes standard and modular, Nerdalize can service them with basic technicians in the field. Quoting again from the company website: “We can use the same processors for about 3 years before their economic lifetime is reached. Our simple design allows a service mechanic to easily replace parts to keep the heater in operation.” I also wanted to know about storage etc. I've been involved in projects using AWS (Amazon Web Services) and know that cloud compute and cloud storage are not one in the same. In their email back to me, Nerdalize noted “We only provide temporary storage for you computations [and] as of now [we] focus on processing.” In other words, if you are a user of their services, store your results locally. They do provide temporary local compute storage using solid state drives (SSD) at the nodes.
Nerdalize notes they use Docker® containerization as their core technology. My guess is this appeals to their targeted customer base, which Nerdalize says are “clients from industry and academics where it can be put to good use. Uses can include, medical research video transcoding, complex engineering models and several forms of scientific computing.” An interesting aspect of this model is that while you want the CPUs and memory to be fast, as long as you have a use for the heat, you don't need them to be on the cutting edge of efficiency, and given the size of a typical heat register (what the Nerdalize heater would replace) you don't need cutting-edge miniaturization either. That implies that some mature CPU and analog power devices might work just fine, which could keep the cost of such nodes very low. What do you think? Could this idea be scaled into industrial and commercial buildings giving new meaning to smart buildings?