May 27, 2025

Strategies to reduce the carbon footprint across the value chain

As the media industry continues its shift from traditional broadcast to digital streaming, a pressing issue is gaining prominence: the environmental cost of streaming video. In response, the HbbTV Association recently hosted a well-attended webinar titled “Sustainability in Streaming – How to Reduce the Carbon Footprint,” featuring industry leaders and experts from Greening of Streaming, the EBU, Deutsche Telekom, Fraunhofer FOKUS, and the LoCaT Project. With over 125 registrants, the event underscored the sector’s growing awareness of the environmental implications of video delivery and the collective responsibility to act.

Measuring the Problem: Where Does the Energy Go?

Ben Schwarz, President of Greening of Streaming, opened the session by underscoring the sheer complexity of the streaming delivery chain, often involving up to 60 devices between content encoding and end-user consumption. Greening of Streaming, a member-driven non-profit organisation, has developed the REM (Remote Energy Measurement) platform, enabling real-time energy monitoring across various stages of the delivery chain, from encoding to telcos and CDNs, all the way to consumer devices.

Their measurements are already uncovering surprising insights. For example, encoding with H.265 rather than H.264 significantly increases power consumption, and devices using video conferencing applications like Zoom can draw 10 watts more power when video is enabled. Even seemingly minor elements, such as the colour and brightness of a video, can contribute to measurable differences in device energy use, especially when scaled to millions of devices. As Schwarz highlighted, “Streaming at scale makes every milliwatt count.”

The Broadcaster’s Dilemma: Losing Control in a Fragmented Ecosystem

Hemini Mehta, Senior Sustainability Lead at the EBU, offered a broadcaster’s view, reflecting both the opportunities and uncertainties in transitioning to greener streaming. The European picture is nuanced: while traditional TV still dominates video consumption in countries like Italy, France, and Germany, viewership among younger audiences is declining, particularly in the UK. This generational shift toward streaming services brings with it significant sustainability challenges.

Mehta noted a major gap in broadcasters’ ability to assess and report emissions: the lack of reliable energy data from end-user devices. Despite knowing that consumer devices typically consume more energy than the entire delivery chain, broadcasters have little insight into the power draw of different TV models or streaming scenarios. Compounding this issue is the challenge of defining “scope 3” emissions: should the energy used by a viewer’s television fall under the broadcaster’s carbon accounting?

She also raised a tension between energy efficiency and creative intent. Efforts to darken screen images, reducing energy use without affecting viewer perception, are promising, with BBC research suggesting potential savings of up to 20%. Yet any modifications to picture quality can risk infringing on artistic direction, particularly in premium content genres. Broadcasters, as custodians of brand and quality, need visibility and control over any alterations made during playback, something not always guaranteed in the current ecosystem.

The Case for Broadcast: Energy Efficiency at Scale

Vincent Grivet, HbbTV Chairman as well as Founder and Coordinator  of the LoCaT Project, presented striking data quantifying the environmental cost of TV delivery. According to LoCaT’s 2020 study, European viewers watched nearly 300 billion hours of TV annually, with DTT (Digital Terrestrial Television) accounting for half of that. However, DTT used only 10% of the energy required across all platforms, compared to 50% from OTT streaming services, which delivered only one-third of total viewing.

This discrepancy highlights the immense efficiency of broadcast over IP-based delivery. Replacing DTT with OTT for live television would require an estimated net 19000 gigawatt hours more electricity, roughly the output of 1.5 nuclear power plants, and potentially add €7.7 billion in telecom network costs annually. The carbon impact would also rise significantly.

Grivet proposed that rather than abandoning broadcast, the industry should enhance it using HbbTV and DVB standards. HbbTV enables broadcasters to offer interactive services, addressable advertising, and application-style UIs through specifications like HbbTV Targeted/Addressable Advertising (HbbTV-TA) and HbbTV Operator Application (HbbTV OpApp). DVB-I and multicast adaptive bitrate streaming (DVB-MABR) were also cited as tools to bring broadcast-grade efficiency to connected devices. A hybrid “push and cache” model for VOD, combining broadcast delivery with local caching, could further reduce energy consumption by an estimated 920 kilotons of CO₂.

Devices in the Spotlight: Where the Power Really Goes

Robert Seeliger, Senior Project Manager Future Applications and Media Sustainability Lead at Fraunhofer FOKUS  emphasized the importance of understanding and optimizing energy use at the device level, especially given that consumer devices account for more than 80% of total energy use across the streaming chain. The German research institute’s  Green Streaming project is developing an automated measurement framework that evaluates energy use across various content attributes (e.g. brightness, bitrate), device properties (screen technology, energy modes), and network conditions.

A key takeaway: reducing bandwidth or resolution has limited energy benefits on modern TVs and smartphones, as decoding is highly efficient. The screen itself is the main energy draw, especially for OLED and LCD devices. Enabling built-in energy-saving modes yields the most significant reductions, often more than 20%.

Fraunhofer FOKUS has even developed a client-side solution, GreenView, which uses an intelligent overlay to subtly darken video without degrading the perceived quality. Early trials show 15–20% energy savings without compromising user experience. However, the lack of standardised APIs for devices to communicate their energy modes or settings hampers broader implementation.

To address this, Seeliger called for an industry-wide push, potentially within HbbTV, to define and standardise energy-related APIs that could give applications insight into device settings and enable optimisations that respect both viewer quality and environmental targets.

Distribution Networks: Rethinking Idle Capacity and Efficiency

The final presentation by Peter Pogrzeba, Senior Project Manager, Deutsche Telekom Laboratories, focused on the distribution side of streaming, particularly the energy consumption of network infrastructure. He introduced two models for evaluating network efficiency: the energy intensity model and the generic power model. The former links energy use to data transfer rates, while the latter considers power consumption over time, offering a more realistic picture.

One surprising insight: telecom networks consume 70–80% of their total energy even at low load levels. This makes network utilisation a critical factor, idle capacity equals wasted energy. Strategies like component hibernation and scheduled shutoffs during off-peak hours are thus essential for energy-efficient operations.

Pogrzeba ’s analysis showed that fibre is the greenest access technology for streaming, with the lowest operational energy consumption per gigabyte. However, satellite remains the most energy-efficient method for broadcasting, due to its wide reach and shared delivery. He concluded by reinforcing that device CPEs (customer premises equipment) continue to dominate energy usage across both fixed and mobile networks.

A Call for Collaboration and Innovation

The presentations made it abundantly clear that improving the sustainability of streaming is not a task for any single actor. Instead, it requires tight collaboration between broadcasters, manufacturers, telecom operators, standardisation bodies, and software developers. Several recurring themes emerged:

• Transparency is key: Without reliable data and measurement frameworks, sustainability efforts are blindfolded. Metrics must be shared openly across the value chain.
• Focus on the 80%: Since end-user devices consume the lion’s share of energy, optimising them presents the largest opportunity for impact.
• Leverage broadcast: Transitioning live TV to OTT is not only costly but carbon intensive. Hybrid solutions that preserve the strengths of broadcast while meeting modern UX expectations offer a sustainable path forward.
• Standardise energy controls: APIs and device metadata must be developed and adopted to enable service providers to make energy-aware decisions without compromising user experience.
• Creative responsibility: Stakeholders across content production and distribution must engage with the creative community to balance sustainability with artistic vision.

The Road Ahead

The HbbTV community is uniquely positioned to drive progress across many of these fronts. Its standards enable hybrid approaches that combine the best of broadcast and broadband, while its technical ecosystem supports innovation in metadata, device control, and user experience. As was highlighted throughout the webinar, small changes (e.g. better encoding practices, energy-saving modes, caching strategies) can yield enormous energy and carbon savings when applied at scale.

Looking ahead, there is a strong appetite for continuing this dialogue. The upcoming HbbTV Symposium in Istanbul (November 12–13) will provide another opportunity to explore these issues in greater depth and with a broader set of stakeholders.

Until then, one thing is clear: sustainability in streaming is no longer optional, it’s an imperative. And by working together, the media industry can meet its responsibility to both entertain and protect the planet.

Matthew Huntington
Manager of the HbbTV Developer Programme