Data center at sea and in orbit: do they have practical meaning?

The rapid growth in the need for computing resources has led to the construction of a huge number of data centers. The equipment installed in them consumes megawatts of electricity and generates heat. The main issue was energy efficiency, which no one thought about at the dawn of design: today, engineers are increasing power density per rack, reducing PUE (the ratio of total energy consumption to IT equipment consumption) and are engaged in other technological shamanism. Industry leaders are increasingly looking towards unconventional solutions. Today we will try to figure out what is more in this process - fiction or madness.

Data center in space

The cost of shipping goods from the planet is high, there will be problems with hiring qualified personnel to maintain equipment in orbit, there will be difficulties with data transmission - satellite communication does not allow achieving such short response time as fiber-optic lines. There is a problem with cosmic radiation, from which sensitive electronic equipment must be protected. The funniest thing is to utilize the heat generated by IT iron in space more difficult than on Earth. Amateurs call it cold, but space is rather empty, except for the meager content of different atoms, electromagnetic radiation and various elementary particles. Vacuum does not conduct heat, so the only way to dump it into the external environment is electromagnetic radiation, that is, huge heated radiators that will glow in the infrared.

Nevertheless, enthusiasts offer to place data centers in space, although there is no talk of megawatt powers. There are many conspiracy theorists among the space explorers - there is an opinion that the data will not be available to governments and other reptilians in orbit (we would argue about reptiloids). In 2016, the Cloud Constellation company from Los Angeles actively cut investors, promising to place a whole petabyte of data in its own network of satellite servers and communication satellites by 2019. The deadline has already come, but the orbital constellation is not in sight. This did not prevent the Cloud Constellation from raising $ 100 million in 2018 .

Startup ConnectX plans to launch a network of satellites for storing cryptocars and other private data outside the planet, and the British Space Agency has allocated more than 4 million pounds to create a demonstration supercomputer in space. It’s too early to talk about other worlds: mankind hardly sends automatic probes there, what kind of data center is there? And why are they needed if the radio signal from Mars to Earth, for example, goes from 3 to 22 minutes, depending on the relative position of the planets. Less crazy options are also offered mainly in the field of space communications, but so far extra-terrestrial data centers remain a fantasy, with the exception of start-up projectors that have not yet been implemented.

On and under water

From the airless space we descend into the depths of the sea: last summer, Microsoft began the second phase of the Natick project , the goal of which was to create a modular underwater data center. Experiments with diving servers have been going on since 2013, and in 2018 a prototype the size of a sea container was lowered to the bottom off the coast of Scotland. It contains 12 racks in which 864 servers are mounted. Building powerful data centers from such modules near large cities can be cheaper (in theory) than on land. Water has a high thermal conductivity and high heat capacity, so the problem of cooling is simplified. With the data transmission channels of difficulties is also not expected, the technology of laying of marine fiber optic lines has long been worked out.

Engineers inspect Project Natick servers and cooling system based on the Naval Group in France. Photo: news.microsoft.com

In addition, Microsoft has ideas on how to power IT loads of renewable energy sources: tidal turbines, wave energy converters, and even wind turbines installed on the shore. Not without problems: the sea is quite damp, but the electronics do not like dampness. It is clear that the data center modules must be sealed and fault tolerant, they will have to work for a long time without maintenance. To prevent corrosion, the interior of the containers will be filled with nitrogen.

The guys from Google do not dive so deeply, but they are swimming quite confidently. True while on the Internet: in pictures and videos. The idea of ​​placing a data center on board a ship is generally not new, in different variations it has been appearing on the Internet for 10 years already. Someone is limited to barge off the coast, others want to cruise in neutral waters so as not to have problems with the legislation of different countries. You can recall the company Nautilus Data Technologies from the United States, has developed a prototype floating data center. Google engineers have been working on the problem for a long time, but then the corporation lost interest in the idea of ​​sea travel. This did not prevent her in 2017 to patent a data center driven on the waves by kites. These original devices also have to generate electricity.

The basic idea here is about the same as that of diving servers, the use of sea water for cooling. In this case, data centers remain serviced, which is generally pretty good. It is difficult to say how such projects are promising, but they are quite realizable at the current level of technical development of mankind. Floating data centers can be used, for example, in countries with a warm maritime climate and a shortage of building land. In addition, it is a good way to dispose of old ships.

Freekuling in the Arctic

Back from the depths of the sea to land and look at the classic data centers. If we take into account the trend of increasing power density per rack and the care of large IT corporations in the so-called. Hyperscale computing, the problem of heat generation is becoming more serious. To some extent, it can reduce the mod to increase the permissible degree for IT equipment, but the functioning of the traditional engineering infrastructure (cooling and uninterrupted power supply) can go from 30 to 50% of the power consumption of the data center. The main expenditure item at the same time - using powerful air conditioning compressors. A completely logical solution would be to try to at least partially abandon them, using one of the existing free cooling schemes (free cooling).

If you do not go deep into the technical details, there are two options: direct single-circuit cooling of the engine rooms with external air with partial recirculation during the winter period, as well as double-circuit systems with air recirculation in the engine rooms and recuperative devices. In the first case, the heated air from the hot zones is emitted into the atmosphere, and the cold zones are fed clean air from the street. Sometimes it also has to be dried or moistened, and the filters require regular replacement. If it is too cold outside, partial recycling is activated.

The second scheme assumes the presence of two open circuits: the data center air circulates in the internal air, and the air from the street flows into the external air circuit. Heat transfer occurs in the recuperative apparatus. There may also be different options, we will focus on the most interesting - the rotary heat exchanger, which is also called the Kyoto cooling system. The principle of its operation is very simple: a massive metal wheel slowly rotates and transfers heat from the inner loop to the outer one.

Natural cooling cannot, unfortunately, be used all year round because of the stringent requirements for the outdoor temperature: if it is too large, artificial cold settings are automatically turned on. In the northern regions, the use of free cooling allows you to keep them off up to 80% of the time, if you take the average for the year. The most efficient rotary heat exchangers can reduce the proportion of energy consumption of the cooling system to 5–7% of total data center consumption, and this is an excellent result.

Another logical move is to move data centers to high latitudes. Alas, it only partially works. Datacenters in the Polar Region didn’t get acclimatized due to the huge number of difficulties associated with their construction and operation. In regions so remote from civilization, there are problems with power supply and communication channels, as well as with the presence of qualified personnel - few specialists are ready to go to turn the tails of polar bears. The funny thing is, the freezing cold in the system of free cooling can also be expensive because of too dry air. If it is not moistened, a strong static charge will accumulate on the electronic components. Of course, companies are trying to build data centers in the northern regions, but they do not climb into the polar ice and still prefer neighborhoods of megacities.

Heat the house, not the atmosphere

The heat generated by data centers was discharged into the atmosphere, and when it became too much, people began to think about using a by-product for peaceful purposes. The idea of ​​useful heat utilization is obvious, but not so easy to implement due to the unstable demand for it and for a number of other reasons. Due to the high temperature outside, the most problems with cooling arise in the summer, and just at this time the demand for heat from the population is minimal. Nevertheless, there are a lot of similar projects in the West; one of them was launched by Yandex. Her data center heats a small Finnish town .

Results and conclusions

If we abstract from high ideas, the construction and operation of a data center are large capital and operational costs that business would like to reduce. Here we immediately reject the space theme, because with a decrease in costs in the foreseeable future, it is incompatible. Sea projects are possible, but they have not yet emerged from the embryonic stage. It turns out, the only real way to reduce costs - the improvement of traditional data centers. First of all, by increasing their energy efficiency through the use of free cooling and useful heat recovery. In the coming years, this is the main trend in the development of zodostroeniya, and then scientists and engineers can throw us something not so prosaic - fiction sometimes becomes a reality.