Whether it’s a video, film, song, podcast episode, TV programme or webcam image – everything we stream every day has three sources of greenhouse gas emissions. These are the data centres, the network infrastructure and the end devices required.

Data centres are known to be the heart of streaming and account for as much as 25% of the digital sector’s greenhouse gas emissions.
While we stream a film, the data passes through a multitude of data centres almost simultaneously. From the moment we press the play button until the moment the entire video is loaded on our computer, the data travels a distance of several thousand kilometres, passing through an entire network of servers that run 24 hours a day and rely not only on operating power but also on energy-intensive air conditioning systems for cooling. The longer the distance and the number of servers the data passes through, the higher the power consumption and thus the greenhouse gas emissions.

The potential for savings here lies primarily in the type of energy used to operate the data centres and the energy-efficient use of the server locations. In order to establish sustainable solutions to this, it is first and foremost the streaming services themselves that are in demand, the largest of which in Germany are Netflix with 31% market share and Amazon Prime Video with 30% market share.

Netflix is pursuing a 1.5-degree strategy that corresponds to current climate research and is implementing it together with its business partners. This is how the company sees itself on the path to reducing emissions.
Netflix uses Amazon Web Services (AWS) data centres, which are to be powered by 100% renewable energy by 2025 at the latest.

Amazon, which not only operates the streaming service Prime Video, but is also one of the world’s leading providers of cloud computing and operators of data centres with its subsidiary Amazon Web Services (AWS), is considered the world’s largest consumer of renewable energy. Their share in all operations, including the operation of the data centres, was around 85 percent by the end of 2021.
Amazon itself operates a large part of the wind power and photovoltaic plants required.

Disney+, the third largest streaming provider in Germany with a market share of 21%, also uses Amazon Web Services data centres.

Apple is also both a streaming provider – albeit one of the smaller ones with a 4% market share in Germany in 2022 – and an operator of data centres. The company currently maintains eight of its own data centres, spread across North America, Europe and Asia, and states in its 2022 Environmental Progress Report that they are powered 100% by electricity from clean, renewable sources such as solar, wind, hydropower and fuel cells for biogas.

The largest video platform for user-generated content, YouTube, uses Google’s data centres, which it says are powered 100% by renewable energy. From 2030 at the latest, Google wants to operate CO2-free.

The music streaming service Spotify is a member of various sustainability initiatives. The company’s declared goal is to also achieve net zero emissions by around 2030. The company is certainly helped by the fact that it closed all of its own data centres in 2018 and migrated to the Google Cloud.

In order to make data centres more economically effective, technology giants such as the aforementioned Apple and Amazon, for example, have been increasingly relying on uniform computer architectures for the construction of data centres for several years now, which can be easily and quickly scaled up to any desired expansion level. The resulting hyperscale data centres are not only optimised in terms of performance, capacity and scalability, but also in terms of energy efficiency due to their centralised and effective mode of operation. Thus, as the demand for data centres continues to grow, hyperscale data centres can definitely help reduce emissions.
A data centre is generally considered to be a hyperscaler if it is around 10,000 square metres in size and has an average capacity of more than 25 MW.

Unfortunately, the move towards hyperscale data centres also has drawbacks at the expense of sites: If the number and size of data centres continues to grow, then in the foreseeable future there will no longer be enough production capacity for the energy required at the site. The data centres and thus also streaming could then lead to blackouts in the regions concerned.
Even if the operators of data centres generate the energy needed to operate the facility themselves by setting up wind turbines or solar parks, as Amazon, for example, has been doing for several years, another important factor remains to be considered: The areas on which the data centres and especially hyperscales are built are no longer available for other purposes. To put it bluntly, sooner or later the question will arise: “Would we rather stream or eat?

With regard to the sustainability of data centres, developments in energy-efficient use are a ray of hope.
The cooling of data centres in particular consumes a large part of the energy used. In the past, the heat produced during the cooling process mostly went unused because servers were usually cooled with air. Nowadays, more and more research is being done on liquid-cooled servers, because in contrast to cooling with air, cooling with liquids allows the energy produced to be captured and reused.
Water-cooled server systems are already in use in many places.
For example, at the Dresden-based company Cloud&Heat. During our VAST DevDay 2022 in Dresden, the VAST FORWARD team gained an insight into how the data centres of the provider of energy-efficient, scalable, secure and future-proof server solutions work and function. In terms of sustainability and energy efficiency, Cloud&Heat relies on space-saving and more environmentally friendly water cooling to operate its data centres.
By recovering waste heat, the cooling systems of the Cloud&Heat servers are simultaneously used for heating purposes in buildings. In the process, water-cooled heat sinks are installed directly at the hotspots of the servers, which achieves a high packing density of the server racks and at the same time reduces the energy consumption of the cooling system.
It is also possible to heat rearing facilities for animals and plants. In view of the steeply rising population curve of our planet and the accompanying increasing lack of space, this also opens up exciting solutions for feeding the world’s population, for example in the field of vertical farming.

Other companies, such as Amazon Web Services, are using evaporative cooling in combination with modular on-site water treatment systems to reduce the amount of water consumed in order to make their data centres more energy efficient.

In fact, in 2020, US researchers showed in a study that data centres are becoming more efficient and therefore also consume less energy than was sometimes predicted.

However, the study also points out that investments in improving the energy efficiency of data centres must continue in the future. Especially because more and more data is being transmitted worldwide.

Sources:

Sustainability of streaming by bitkom.org (DE)
Video-streaming and CO2 by bitkom.org (DE)
Data centres Hunger for power by it-daily.net (DE)
Frankenstream by arte.tv (EN)
Amazon 2021 Sustainability Report by amazon.co.uk (EN)