Clément Pellegrini

How many Earths could we save by using our IT differently ?

January 11, 2018 - Green IT

CC Adriano / Adriano

We found that if only 10% of data centres-located computations was distributed in buildings to reuse wasted heat, greenhouse gases emissions could be cut by 26 million tons annually. This is the equivalent of 26 million round trips by plane between Paris and New York (see here). This is also slightly more than the total amount of CO2 annually absorbed by our oceans and seas all around the world (see here)...

A look back at green IT

Our planet faces climate change, since the 80’s we first blamed mainly traditional industries, transport or electricity production and the use of fossil fuels. Many improvements have been achieved toward energy efficiency regarding these activities, either for ecological reasons but also for economical reasons of course. Nevertheless a new industry has emerged during the 90’s, and is still growing exponentially since, the Internet and every online services often known as “the cloud”. Data centres, our modern digital factories, use at least 3% of the world electricity, according to Greenpeace. In France this share even amounts to 9%. And this trend is expected to pursue a very significant growth over the coming years. Indeed, with the massive introduction of IoT for example, this could represent a threat for electricity grids stability, which is thoroughly investigated in Ireland for each of the new GAFAM infrastructure projects for example. Yes, IT has an environmental impact but we don’t talk too much about it. The other concern relates to the actual use of this electrical energy. Data centres use electricity first of all for the IT equipment, but due to intense use and high density of servers, an important share of the electricity is used for cooling. Heat is a waste for IT industry, and a danger for computers, therefore important amounts are dedicated for A/C installations and operation. This problem is beginning to be taken seriously since only few years.

Estimating our potential impact on GHG emissions

As part of the solution, Qarnot created the first computing heater using microprocessors as a heat source: the Q.rad. Installed in homes and offices, Q.rads form a distributed cloud infrastructure where computing power is no longer deployed in concentrated data centres but split throughout the city. Avoiding the costs faced by data centres related to infrastructure, maintenance, and cooling, Qarnot offers affordable and energy-efficient computing power. Qarnot has a double-sided business model. On the one hand, Qarnot provides computing power for industries such as 3D animation, biotechnology, finance. On the other hand, Qarnot provide free and green heating by reusing the heat generated by processors. Qarnot is an alternative to traditional data centres, and thus significantly lower the carbon footprint of both data processing and household heating. Thus we thought: how significantly could greenhouse gases be reduced if a distributed IT infrastructure like Qarnot’s was used broadly ? CES2018’s Eureka Park Climate Change Innovators Award gave us the opportunity to dive in this topic. Competing with start-ups from all around the world to be identified as one of the most forward-thinking solutions to tackle climate change, we tried to estimate our solution’s potential in GHG reduction. Imagine if only 10% of computations performed in data centres was performed on the Qarnot system. It is not unrealistic, given the growth of data centres markets : projections of computing-driven markets (including : data centre networking and interconnect market or data centre infrastructure management market) vary on a 10 to 30% range in annual growth! In this 10% scenario, we estimate that by processing a portion of the data usually sent to data centres, and replacing regular heaters with Q.rads to take advantage of the heat produced by servers, Qarnot could have an impact of 26M tons of CO2 annually.


In this estimation, we considered a scenario were Qarnot would take out of data centres 10% of the current electricity consumption dedicated to IT. We considered that we would save the amount of electricity usually dedicated to cooling systems, meaning the difference between the average 1,7 PUE and a PUE of 1.0 (PUE is the ratio between electricity consumption and electricity dedicated to IT. More info about this indicator on Wikipedia). We multiplied it by the carbon footprint of electricity. We considered that we would also save heating in homes and buildings, and related this amount to heating carbon footprint. Considering the following : Electricity production is accountable for 40%[1] of the global CO2 emissions, with 605 gCO2/kWh in 2013[2]. The global impact of data centres is 414K tons of CO2. Data centres create waste two-fold: heat from data processing that goes unused, and the subsequent cooling of this wasted heat. According to Data Centre Knowledge, the average PUE for US data centres in 2014 is 1.7[3]. We use this figure as a low estimate of the global average PUE. An ideal PUE is 1.0. 41% of the energy (lights, cooling systems…) is not used for actual IT operations. On top of that, households around the world consume energy to heat their homes, and millions of them still live in fuel poverty. In 2011, the total final energy use for heating purposes was 2,3250 TWh globally[4]. Considering the global carbon footprint of 228 gCO2/kWh regarding primary energies[5], heating produces 5,3 billion tons of CO2 at a global scale. With Qarnot, no energy is used for cooling systems like data centres’, nor for residential heating on top of it. Qarnot uses the energy produced by servers for free home heating. The methodology doesn’t include the significant CO2 costs implied by the construction of data centre buildings - which Qarnot doesn’t require. We were glad to be selected as a winner of the CES 2018 © Eureka Park Climate Change Innovators award ! One month after Qarnot's exhibition at Tech for Planet, event organized in Paris with French President Emmanuel Macron, this award distinguishes Qarnot's potential to contribute to energy transition and fight climate change.

Worth reading also...

On the environmental impact of Bitcoin (BBC) On the impact of data centres on energy grid (Irish Times) On the integration of Green IT policies in French companies (Alliance Green It /