Keeping servers in thermal equilibrium is an increasingly complex task. Any detail that allows consuming less energy is quickly seized upon by companies, and sometimes the solutions can be quite exotic. IBM knows that servers waste a lot of heat during operation, but the THRIVE project aims to reuse that heat as an energy source for future cooling systems.
The Problem of Waste Heat
Your computer is wasting heat right now. The same goes for refrigerators and air conditioning systems. Heat is one of the main enemies of electronics, and as such we try to reduce its influence as quickly as possible. Yet the truth is that there is energy there, and if we could reuse even a little of it, heating and/or cooling costs would be lower. This level of efficiency may not be so critical for a desktop computer, but imagine an entire server room. Some of the most important companies have been forced to build entire structures to deal with heat, but there are cases where it has been more convenient to recycle old facilities, such as the case of Google in Hamina, whose data center uses seawater.
IBM THRIVE: An Innovative Heat Pump
Crossing into IBM Research territory, we find a very striking project called THRIVE. Its description is relatively simple: Develop a heat pump powered by excess heat (apologies for the redundancy). A traditional heat pump needs a compressor, but the design planned by the THRIVE project replaces the compressor with an adsorption-based heat exchanger (yes, that's how it's written), which uses heat at a temperature around 60 degrees Celsius as an energy source. During the adsorption process, the heat exchanger adsorbs vapor from the evaporator and compresses it inside, releasing heat, while the previously adsorbed refrigerant is forced out of the exchanger (desorption) with the help of an external heat source. The released hot vapor returns to liquid state in the condenser, and the heat obtained there returns to the cycle. As you may notice, the operation of this heat pump is intermittent, so two or more adsorption exchangers are needed in parallel to work without interruptions.
At the same time, this system needs a medium, and according to the researchers, it is a substance very similar to the silica gel found in those small packets inside shoeboxes, pockets, and electronic components. Initial calculations speak of a 65 percent reduction in energy consumption for heating and cooling, and an 18 percent reduction in solid fuel consumption for heat generation by the year 2040 (this takes Switzerland as a reference). A 65 percent reduction implies that the system still requires electricity (so the demons of thermodynamics still take their share), but if that difference can be transferred to data centers, the benefit will be enormous. THRIVE is a three-year project, and I imagine we will hear more about it soon.
