Green Cloud Computing – Green Power Usage Effectiveness

Over the next several weeks we will be focusing on “Green Computing Technology” and will be presenting articles from those who are currently working and developing in this area.  One of these companies is Greenqloud that we have previously covered on our:” Top 25 European Cloud Computing Rising Stars List”

In the meantime, here is an excellent article written by Eirikur Hrafnsson, CEO & Co-Founder Greenqloud that was originally posted back in October 2010 discussing a Power Usage Effectiveness Scale or PUE.

You can expect future contributions to CloudTweaks from Eirikur Hrafnsson as well as Environmental Manager, Ruth Shortall in the following weeks…

Original Article:

A few years back the Green Grid developed the Power Usage Effectiveness metric or PUE for short to measure a data centers’ effectiveness of getting power to IT equipment. What the PUE tells you in simple terms is how much extra energy you need for each usable KWh for the IT equipment due to the power going into cooling, power distribution loss etc. and it’s a simple formula (in theory):

PUE = Total Facility Power/IT Equipment Power

However the PUE “standard” has been the center of the data center industries’ debate ever since it came out. I won’t go into the details but it has been debated mainly for four reasons.

  1. The PUE can change dramatically depending on where measurements are made, when they are made and the timespan the measurements are made in.
  2. Data centers are subtracting factors from their PUE to lower it e.g. district heating.
  3. PUE was designed for dedicated data centers (preferably full of gear) but being calculated for any kind of “data center”.
  4. PUE was NOT designed as a metric to compare data centers for business purposes (My PUE is smaller then yours!) but as a metric for data centers to improve their effective use of power.

In other words PUE has loopholes and they are being exploited for marketing purposes. Green Grid has decided to plug most of those holes with an update to the PUE definition and are now calling it PUEx where the x is a value between 0-3 and depends on e.g. where measurements are made. You can read more about the PUEx here .

PUEx is a welcomed update and I hope data centers will soon start updating their PUE’s. I still have a beef to pick with the marketing departments of the data centers though because I don’t see them stopping to use PUE as tool to compare their “green” data center to others. The age of “Green by PUE” has just started, believe me!

This article about “Chicago emerging as a green data center powerhouse” is exactly the sort of “greenwashing” we have been spotting here at Greenqloud. Microsoft has a massive “green” data center in Chicago that they say has a PUE of 1.22, sounds pretty great right? But wait…where does their power come from? 72.8% coal, 22.3% nuclear, 3.8% mixed, 1.1% renewable…still sounds green to you? Me neither and we feel like something has to be done. PUE rightfully does not change with the amount of renewables used. It simply isn’t a metric about true greeness but how well you manage your power and therefor should not be used for green marketing.

However, PUE IS being used for green marketing and realistically I don’t think that will change for a while. We therefor came up with a way to “weigh” the PUE to better see which data centers are truly green in the sense that they indirectly cause the least amount of CO2 to be emitted by their use of dirty or clean energy.

This new metric we call GPUE or Green Power Usage Effectiveness and it does two things for the industry.

  1. It gives the truly green data centers a boost in the battle with their “greenwashing” counterparts.
  2. You can very easily calculate the CO2 emissions created for each usable KWh for the IT equipment.

So here’s the definition and the presentation format for GPUE:

GPUE = G x PUEx (for inline comparison of data centers)
or = G @ PUEx  (a better display and for co2 emission calculations)

The “G” is the key factor here and it is a simple calculated value:

G = Weighed Sum of energy sources and their lifecycle KG CO2/KWh

G =∑( %EnergySource x ( 1 + weight) )

What’s the + 1 for? It’s there so we when “weigh”(multiply) the PUE we get a number that’s not less then the PUE. This gives us a better feeling of the scale because we are used to the small PUE value range.
The weights are simply taken directly from the “lifecycle CO2/KWh for electricity generation by power source” table above we got from the 2008 Sovacool Study e.g. the weight for unscrubbed coal is 1.050 (kg of CO2/KWh) while hydroelectric river generation has a weight of 0.013. An unknown energy source or a “mix” will get the same as the maximum value which for now is the same as coal.


PUE 1.20, 50/50 Coal/Hydro
G = 0.5*(1+1.050) + 0.5*(1+0.013)
G = 1.531, GPUEx =
1.84 or 1.531@1.20

Kg CO2 per usable KWh = (G-1) x PUEx = 0.64 Kg

It’s very interesting to see the GPUE side by side to the PUE of these “green” data centers in the image below (click for a large version). This table is mostly taken from the Greenpeace report “Make IT Green“. You will notice the percentages don’t quite add up, that’s because these are the local grid suppliers, the rest is what we call a “mix”. Some of those data centers also didn’t have a public PUE (underlined) so for demonstration purposes we gave them a PUE of 1.5 and did the calculations. Greenqloud’s data centers don’t have their PUE yet but from Icelandic experience and the free cooling here we are certain that they will at least be under 1.2 and because we only use 100% renewable energy (geothermal and hydro) for our truly green public cloud our GPUE will roughly be equal our PUEx and that’s the point. Truly green data centers will have a GPUE close to their PUEx and dirty energy data centers won’t, let the debate begin!

Please leave your comments, share on twitter etc. I would love to hear your thoughts on the subject!

By Eirikur Hrafnsson, CEO & Co-Founder Greenqloud


Green Power Usage Effectiveness

Share on Facebook
Post to Google Buzz
Bookmark this on Delicious
Share on Tumblr
Share on reddit
Share on LinkedIn
Share on StumbleUpon


The ICT industry is putting out 2% of the world’s CO2 emissions, equal to the airline industry (Gartner) and could become one of the biggest polluters by 2020 (McKinsey).

About CloudTweaks

Established in 2009, CloudTweaks is recognized as one of the leading authorities in connected technology information and services.

We embrace and instill thought leadership insights, relevant and timely news related stories, unbiased benchmark reporting as well as offer green/cleantech learning and consultive services around the world.

Our vision is to create awareness and to help find innovative ways to connect our planet in a positive eco-friendly manner.

In the meantime, you may connect with CloudTweaks by following and sharing our resources.

View All Articles

Sorry, comments are closed for this post.

CloudTweaks Comics
Despite Record Breaches, Secure Third Party Access Still Not An IT Priority

Despite Record Breaches, Secure Third Party Access Still Not An IT Priority

Secure Third Party Access Still Not An IT Priority Research has revealed that third parties cause 63 percent of all data breaches. From HVAC contractors, to IT consultants, to supply chain analysts and beyond, the threats posed by third parties are real and growing. Deloitte, in its Global Survey 2016 of third party risk, reported…

Data Breaches: Incident Response Planning – Part 1

Data Breaches: Incident Response Planning – Part 1

Incident Response Planning – Part 1 The topic of cybersecurity has become part of the boardroom agendas in the last couple of years, and not surprisingly — these days, it’s almost impossible to read news headlines without noticing yet another story about a data breach. As cybersecurity shifts from being a strictly IT issue to…

How Formal Verification Can Thwart Change-Induced Network Outages and Breaches

How Formal Verification Can Thwart Change-Induced Network Outages and Breaches

How Formal Verification Can Thwart  Breaches Formal verification is not a new concept. In a nutshell, the process uses sophisticated math to prove or disprove whether a system achieves its desired functional specifications. It is employed by organizations that build products that absolutely cannot fail. One of the reasons NASA rovers are still roaming Mars…

The Cancer Moonshot: Collaboration Is Key

The Cancer Moonshot: Collaboration Is Key

Cancer Moonshot In his final State of the Union address in January 2016, President Obama announced a new American “moonshot” effort: finding a cure for cancer. The term “moonshot” comes from one of America’s greatest achievements, the moon landing. If the scientific community can achieve that kind of feat, then surely it can rally around…

Using Cloud Technology In The Education Industry

Using Cloud Technology In The Education Industry

Education Tech and the Cloud Arguably one of society’s most important functions, teaching can still seem antiquated at times. Many schools still function similarly to how they did five or 10 years ago, which is surprising considering the amount of technical innovation we’ve seen in the past decade. Education is an industry ripe for innovation…

Using Private Cloud Architecture For Multi-Tier Applications

Using Private Cloud Architecture For Multi-Tier Applications

Cloud Architecture These days, Multi-Tier Applications are the norm. From SharePoint’s front-end/back-end configuration, to LAMP-based websites using multiple servers to handle different functions, a multitude of apps require public and private-facing components to work in tandem. Placing these apps in entirely public-facing platforms and networks simplifies the process, but at the cost of security vulnerabilities. Locating everything…

Your Biggest Data Security Threat Could Be….

Your Biggest Data Security Threat Could Be….

Paying Attention To Data Security Your biggest data security threat could be sitting next to you… Data security is a big concern for businesses. The repercussions of a data security breach ranges from embarrassment, to costly lawsuits and clean-up jobs – particularly when confidential client information is involved. But although more and more businesses are…

Update: Timeline of the Massive DDoS DYN Attacks

Update: Timeline of the Massive DDoS DYN Attacks

DYN DDOS Timeline This morning at 7am ET a DDoS attack was launched at Dyn (the site is still down at the minute), an Internet infrastructure company whose headquarters are in New Hampshire. So far the attack has come in 2 waves, the first at 11.10 UTC and the second at around 16.00 UTC. So…

The Conflict Of Net Neutrality And DDoS-Attacks!

The Conflict Of Net Neutrality And DDoS-Attacks!

The Conflict Of Net Neutrality And DDoS-Attacks! So we are all cheering as the FCC last week made the right choice in upholding the principle of net neutrality! For the general public it is a given that an ISP should be allowed to charge for bandwidth and Internet access but never to block or somehow…

A New CCTV Nightmare: Botnets And DDoS attacks

A New CCTV Nightmare: Botnets And DDoS attacks

Botnets and DDoS Attacks There’s just so much that seems as though it could go wrong with closed-circuit television cameras, a.k.a. video surveillance. With an ever-increasing number of digital eyes on the average person at all times, people can hardly be blamed for feeling like they’re one misfortune away from joining the ranks of Don’t…

Cloud Infographic: Security And DDoS

Cloud Infographic: Security And DDoS

Security, Security, Security!! Get use to it as we’ll be hearing more and more of this in the coming years. Collaborative security efforts from around the world must start as sometimes it feels there is a sense of Fait Accompli, that it’s simply too late to feel safe in this digital age. We may not…


Sponsored Partners

Security: The Goodwill Virus That Keeps On Giving
Salesforce Service Cloud: Air Traffic Control For Your Customer
Cyber Security: An Ounce of Prevention
Collaborative Economy – The Death Of “Death By Meeting”
Help Your Business Improve Security By Choosing The Right Cloud Provider
Skin Based Technology – The Intelligent Tattoo
The Value of Hybrid Cloud
Security Training Through Practical Experience
SAP HANA® And Global Healthcare
Watching You Shop: Stores And Mannequins “Read” Their Customers And Respond
Competing Cloud Security Demands Call For Credentialed Professionals
Collaborative Economy – Customer Appreciation Day