I am a regular user here and have no knowlage or links to Githubs organisation.
That being said, I am a Datacenter Design Specialist, which means I know everything about Datacenters, from the airflow, the wiring, power and cooling, backup power, security, positions of hardware and all the hardware themselves. I have a vast knowhow about every detail involving datacenters and how they work, from soon 20 years experience as a solution provider of IT.
To own a datacenter is something only larger companies or high security companies even consider doing. Goverments can own minor datacenters for specific data, but even nations often rent datacenters from IT providers, who can offer 100% secure data.
The most common solution for businesses is to rent parts of a datacenter where you put your stuff. But even that is getting less and replaced by a virtual datacenter, which gives the company the IT hardware, with an overview and detailed cost, but where the actual hardware is…can be anywhere and split in tons of different locations.
My professional view is that Github doesnt fit the profile of a company who would need, or want, to carry the cost of a datacenter they own. My educated guess is that they have a small room with hardware for their company IT, and they rent a virtual datacenter from Microsoft, Amazon, HP or whatever, where they host their “servers”.
Note: I have NO INFO what so ever about what Github is using, nor do I claim that I “think” I know what they have.
This is only my professional opinion regarding a company profile as Github (I am not even talking about them specificly).
I can however enlighten you, and others, a bit about “green energy” and Datacenters.
How “green” a datacenter is, is NOT dependant on where the power comes from.
About 35-55% of a datacenters power is COOLING. That includes every single minifan in a server, to the cooling system of the physical building.
The cooling of datacenters is a moving part that depends HIGHLY on the choice for cooling the building. And second, the airflow and position of the hardware in the datacenter. Just moving servers around, can reduce the avarage heat with 10-20%.
And the choice of cooling system is paramount. For example, a datacenter location has the highest impact on how much power is needed for cooling. Let me explain.
Datacenter A is located in, lets say Texas, USA, which has a warm climate the majority of the year, will require a significant powerconsumption for cooling. The cooling system needs to be some kind of AC, that keeps the buildings temp lower then the outside, 24/7.
The same Datacenter A, located in Kiruna, North part of Sweden, Scandinavia, which has a cold climate the majority of the year (Below 0C, freezing temp). And will not require any power to any cooling system.
The datacenter gets cooled by using the outside air with a complexed “airflow” in the building, which can be calibrated with fans and opening/obsticles for max effective cooling on every single hardware.
The airflow system, calibration and cooling requires constant overview and minor alterations, made by highly skilled proffesional techs. But the cost for this, is nothing vs the power cost of cooling systems.
Facebook owns one of the largest datacenters for single companies, and they moved most of their Datacenters to north of Scandinavia. Only cause of the cooling. And not because they wanted to be “green”. But 6 large datacenters cooling avarage a cost per year in pure power for cooling around 50-100M USD.
Moving their datacenters to dry, cold air, below 0C (water freezing mark), removes the whole power bill and replaces it with cost for management. 5M USD per year, is a high number.
A green datacenter, needs to be compaired how much power it uses and where the power comes from.
Because lots of “green” datacenters, loves to brag about using green energy, from renewable sources. But fails to include the energy they have to buy from not green sources, when the green sources cant provide power for a short time.
Also, the choice of cooling system, can negate the choice of where the power comes from, quite easily.
The most green datacenter, are those who use outside air, as cooling, and use nuclear, Hydro or solarpanel power.
And even in those cases, you will want to know how much power the building as a whole is using per year. All included.
Hope this wall of text helps!
–Jonas, The Swedish Goth