Datacenter-Link Blog

In 1882 Edison switched on the world’s first large-scale electrical supply network that provided 110 volts direct current to fifty-nine customers in Manhattan; in 1883 in Milan, between Santa Radegonda and Agnello streets, started the production the 1st power station among Continental Europe.
The birth of the first power stations was a crucial junction in the evolution of modern society: not for nothing that this event was one of the most important of those that characterized the so-called Second Industrial Revolution.
In his book “The Big Switch: Rewiring the World, from Edison to Google,” (W. Norton & Company, 2009), American writer Nicholas Carr draws a suggestive analogy between the rise of the very large data centers as the ones built recently and the Second Industrial Revolution. Just as nascent industries, once powered by water wheels, began able to run their machines thanks to constant and reliable voltage generated in distant power plants, advances in technology and transmission speeds are permitting computing to function like one utility, a distant but reliable source of services. Really, this is exactly what the CEO of Google, Eric Schmidt meant when last May in one of his speech said to the press that “The Browser is the Computer”.
The metaphor is interesting: we can expand it. Till the 90s, computers used to be stand-alone devices. If you wanted to do something more than looking at the prompt line, you had to buy a software and install it on your PC. Then, the World Wide Web arrived in the late 90s. Suddenly, if you had a network connection and a browser, you could read pages and pages of information not contained in you hard disk. Think about YouTube, MySpace, Facebook, Wikipedia, Google Search, Yahoo Mail: none of those programs is running on one PC’s hard disk. They’re all utility services that everyone can share with people living in every part of the world. And what is very interesting is that no one really cares where our software is coming from, what are the features of this software, in which way it is using the PC: if it works it’s OK. The PC began to be fed by outside, and the focus started to be on the connection.
The analogy is clear: the development of the electric grid move the focus from the need of appropriate source of power to the need of connection to the grid. No one (except for few electrical engineers) is interested into frequency, voltage, power quality… We trust the Net.

…..TO BE CONTINUED…..

Quotes:
[1] http://www.nicholasgcarr.com/bigswitch/interview.shtml, N. G. Carr
[2] “A Practical Guide to the Early Days of Data Center Containers”, October 29th, M. Manos.
[3] “Data Center Overload”, Published June 8th 2009, The New York Times, T. Vanderbilt
[4] “Estimating total power consumption by servers in the U.S. and the World”, February 15th 2007, J. Koomey.

Tags: data center; electric grid; net; power station

German certification body TUV, has certified that the Uniflair High Density Cooling Solutions are suitable to effectively cool loads of up to 40 kW each rack granting complete reliability and high efficiency of the complete system.The certification process involves the Test Room present in the Uniflair Headquarters dedicated to High density Cooling Solutions having verified the chain of measurement of the equipment installed, acknowledging its precision and reliability.
The ambient was cooled by a Leonardo Chilled Water Precision Air Conditioning unit integrated with AFPS system and the closed racks were cooled by means of Active Floor modules.The Active Floor modules guarantee that the temperature of the air under the floor is lifted to the superior height of the units and to the inside of the rack. Combination with the compartmentalization of the cold corridor is not strictly necessary, even when the system is operating at total capacity.The under floor air discharge temperature can be altered depending on the client’s requirements. According to the project conditions of the chiller, the discharge/return temperature can be designed at an optimum of, for example 12/18, so allowing the use of Free-Cooling for a greater number of hours.The increase by one degree of the discharge temperature from the CRACs allows the use of free-cooling for 300-350 hours per year.Loads of 12, 15, 20, 25, 30, 35 and 40 kW were generated in the test rack by means of resistors. All the loads were safely cooled with a discharge temperature of 20°C. Given that the Active Floor Module works based on the existing installation, the modules which make it up can be used in a rapid and flexible way to resolve the air conditioning problems or to increase energy efficiency, constituting a convenient solution which avoids involving water for cooling of the rack.If compared to “in rack“ cooling this solution, according to the concept, allows a saving in terms of space, guaranteeing a secure investment for datacenter infrastructures cooled through the modular access floor.The first step in existing systems is that of improving the airtightness of the modular access floor and optimization of the under floor pressure.It stands to reason that the cooling of high loads assumes the availability of a corresponding air or cooling capacity in the ambient or rather under the floor.During the tests it was possible to:

• effectively cool all the simulated loads (12, 15, 20, 25, 30,35 and 40 kW)
• transfer the under floor temperature to the upper part of the unit (with the possibility of increasing the discharge temperature by various degrees).
• effectively cool even higher loads with a discharge temperature of 20°C.
• select the optimal temperature for the servers in terms of operating safety and/or energy efficiency.•
• have available, in the event of an emergency, a more than adequate reaction to eliminate possible breakdowns even in the presence of loads of 40kW.
•  make the data center’s air conditioning operate in an optimal way
• simulate redundancy concepts for high capability data centers to eliminate, in a simple and direct way, the phenomenon of hot spots. 

The test examiner expresses a recommendation for the certification according to the catalogue of requisites “TUV certified energy efficiency – High Density Cooling”.

In order for power to be usable (e.g. high-quality), its characteristics must be within the tolerances of the supplied load. Therefore it is not enough for power to be present. Let’s take this necessary condition as the starting point for the analysis.

Power distribution

Information on electrical power quality is somewhat scarse. The main independent sources of information considered here are:

• European Network of Transmission System Operators for Electricity (ENTSO-E);
• The Italian Regulatory Authority for Electricity and Gas;
• Leonardo Energy (LE).

The available statistics respectively refer to High Voltage lines, Low Voltage lines and power quality within the system used. In fact, high-quality power supplies are frequently compromised by consumers’ loads within their own plants, such as non-linear loads or loads with high inrush current. Unfortunately, the lack of information on Mdium Voltage lines, which is of extreme relevance to all consumer loads connected via transformer to the grid, does not allow for a complete analysis. The reason probably stems from the fact that individual quality standards are defined in Medium Voltage.
The ENTSO-E Statistical Yearbook 2008 provides an overview of electricity exchanges between European nations and lists the major periods of unavailability, classified according to the reason:

• Maintenance
• New construction
• Overload
• Failure in protection devices
• Outside impacts (animals, plants)
• Atmospheric agents
• Other reasons/unknown

The bottom line is that in 2008, the total downtime of international tie lines of 220 to 380 kV with rated power from 300 to 1745 MVA between Italy and neighbouring countries amounted to approximately 6500 hours.
However as regards low-voltage lines, the Regulatory Authority informs us that in 2007 in Italy, each user experienced 4.73 power outages of between 1 second and 3 minutes and 2.16 power outages of over 3 minutes’ duration, giving a total downtime of 58 minutes.

Tags: grid availability, high voltage, low voltage, mains availability, medium voltage

 Leonardo ENERGY is the premier web site delivering a range of virtual libraries relating to electrical energy.

It is an initiative dedicated to build information centres to serve designers, engineers, contractors, architects, general managers, teachers and students, professionally or otherwise involved with electrical power.

Leonardo ENERGY has developed a micro site dedicated to Data Centres complementary to Datacenter-Link.

Tags: data centre, Datacenter-Link, Leonardo ENERGY