Research & Development

Posted by Jigna Chandaria, Natasha Westland, Chloe Fletcher on , last updated

The Questions

Have you ever wondered about the environmental impact of watching TV? Or considered how much energy is used to stream a programme on BBC iPlayer compared to viewing it live on it BBC One?

This week we are releasing a research paper which answers these questions and more, including the total energy use of distributing and consuming BBC TV services. As there are many ways to watch BBC TV content: terrestrial TV, over satellite or cable, or streaming over the internet, we have broken down our findings by platform and identified which aspects are the most energy-intensive.

This work revisits our previous research of over a decade ago and comprehensively updates it. Back then, we were still in the middle of digital switchover, there were no smartphones or smart TVs, and my 23 inch CRT TV was typical. Clearly, the broadcasting landscape has changed considerably since then, both in terms of technology and the audience's behaviour and expectations.

We teamed up with digital footprinting experts, Prof Chris Preist, Dr Dan Schien and Paul Shabajee at the University of Bristol on this research which looks at:

  • understanding the total energy use of our TV services,
  • compares the different platforms,
  • investigates which parts of the broadcast chain (from transmission to the home) use the most energy and what can be done to reduce it.

Interactive Presentation - BBC R&D Showcase 2020

Choose what you would like our engineers to explain in an interactive experience discussing the environmental impact of the BBC's television services - and how they might look in years to come.

The Answers

The total energy use across all four platforms of terrestrial, satellite, cable and iPlayer for 2016 was 2,000 GWh which was 0.6% of total UK electricity use.

We found that the energy use of streaming video per hour (0.19 kWh/device-hour) is similar to that of satellite (0.16 kWh/device-hour) and cable (0.15 kWh/device-hour); terrestrial television uses less than half of the other platforms (0.06 kWh/device-hour). (Updated and revised figures in bold, June 2021)

For every platform, we found that the devices in the our audiences' homes used more energy in total than in our distribution chain. Overall, the home equipment (including mobile phones) accounted for over 90% of the total energy use. We found this surprising as often TV transmitters are thought of as being big power hungry sticks on hills compared to TV sets and set-top boxes, but it turns out that when you add them all up together, they massively dominate.

There's much more detail about the methodology, scope and assumptions in the White Paper along with information about the uncertainty and sensitivity of the results.

BBC R&D - Sustainable Engineering

BBC R&D - Using Behavioural Data to Assess the Environmental Impact of Electricity Consumption of Alternate Television Service Distribution Platforms

A TV transmitter on a distant hill in the countryside.

Image above by Dave Pickersgill on Geograph, cc licence.

Future Changes

Having worked out our current environmental impacts, we then wanted to know how they might change in the future.

We don't have a crystal ball to make forecasts, so instead, we have explored a range of 'what if...?'; scenarios to see the range of possibilities, and importantly see which variables make the biggest difference. We did this by running our system model with a different set of parameters to reflect each scenario. Although the scenarios are not forecasts or predictions they illustrate where very clearly the 'hot spots', i.e. the most power-hungry parts of the broadcast chain, so that we know where to focus our efforts to make the biggest savings. The scenarios also highlight the potential for energy savings in the system overall.

Sharing our results from afar

One of the three pillars of the BBC Greener Broadcasting strategy is focused on Our Industry. We are committed to reducing the impact of media technology through industry collaboration. We need to work together to find the best way to reduce the environmental impact of the whole broadcasting eco-system, which is why we're sharing everything we've learnt with the rest of the industry.

Ordinarily, this may have involved going to a conference to spread the word, and hopefully opening interesting conversations on working together to reduce our energy consumption.

In light of the recent global pandemic, and also with our sustainability hats on, we thought the next best thing would be to share the findings of our research in an interactive demonstration! And luckily, it also showcases another one of BBC R&D's projects: an object-based media experience design tool called StoryFormer.

StoryFormer allows a more interactive and personalised viewing experience. Although we can't be with you in person to discuss sustainable engineering at the BBC, we hope that this demonstration engages you. Please bear in mind this was filmed in our researchers' homes and not with the world class production teams who usually set the high standards of the BBC!

If you have any questions or comments, please get in touch, in the meantime we hope you enjoy the presentation, which takes about 20 minutes to navigate.

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BBC R&D - Sustainable Engineering

BBC R&D - Using Behavioural Data to Assess the Environmental Impact of Electricity Consumption of Alternate Television Service Distribution Platforms

BBC R&D - The Carbon Footprint of Watching Television

BBC R&D - From Lens to Screen: An Industry Collaboration for Sustainability

BBC R&D - Sustainability in broadcast and digital media

BBC R&D - Sustainability in broadcast and digital media: Video Coverage

BBC R&D - Understanding and Decreasing the Network Footprint of Catch-up TV

BBC R&D - A comparison of a Carbon Footprint of Digital Terrestrial Television with Video On-Demand

This post is part of the Broadcast and Connected Systems section