How energy-intensive is online learning? Image: Green Living Blog, 2021

Azimzadehirani, M. (2021) Is effective online learning bad for the environment? University Affairs, August 23

This interesting article is as much about whether or not students should turn off their cameras during emergency remote learning as about energy consumption (a small survey of 33 students in two Canadian universities found that 40% kept their camera off during Zoom lectures).

Energy – and cost – issues


However, the article also gives some interesting information about the energy consumption of videoconferencing, from Renee Obringer, a postdoctoral research fellow at the National Socio-Environmental Synthesis Center in Maryland:

A standard video conference uses 2.5 gigabytes per hour and has a carbon footprint of 157 g of CO2. If one individual has 15 one-hour meetings in a week, his monthly carbon footprint would be 9.4 kg.

…if one million videoconference users kept their cameras off, they would reduce emissions by 9,023 tons of CO2 in one month, which is about as many emissions as it takes to power a town of 36,000 people over that time.

Probably just as important as energy consumption though is the demand videoconferencing puts on domestic Internet access, particularly if there are multiple users sharing the same bandwidth at the same time, as was common during the pandemic. Videoconferencing will increase costs if users are charged for more than minimum bandwidth use, and it will reduce access if the home does not have more than 10 MB/second download speeds.

Learning management systems

If one is going to worry about energy consumption, you can’t just look at videoconferencing. Before the pandemic, most online learning was asynchronous, using a learning management system. What is the average energy consumption for this use of technology? This will be more difficult to calculate, but it should be possible to make some reasonable estimates.

Learning management systems require between half to a third of the bandwidth of a video conferencing application. Most LMSs can track the amount of time each student is ‘engaged’ with the LMS. Presumably students will spend more time on the LMS than they would on videoconferencing but this needs to be measured and verified to see whether the energy consumption is more or less than that of courses that are delivered mainly by videoconferencing. If the research has been done, I have not seen it. 

Campus-based teaching

Similarly, if energy consumption is a concern, one needs to look at the energy consumption of campus-based teaching. There are several components, probably the most important being the energy costs of commuting to and from campus. I know that even 20 years ago, UBC was looking at ways to reduce the number of cars coming on campus (VERY expensive parking charges being the most common method at the time). Online and distance learning certainly were likely to reduce the energy costs of computing.

In other words, we need more research on this. My guess is that overall, online learning will turn out to be less energy-demanding than campus-based teaching, but it will depend to some extent on the design of courses and choice of technology

Pedagogical issues in turning off student cameras

In terms of affordances, it does not make much sense to use videoconferencing then expect students not to use the video component. The issue really is: how is the instructor making use of the students’ access to video? Are they maximising the pedagogical affordances of video interaction with students? Is just seeing their faces enough? How could students use their access to video to demonstrate their learning or do research?

Finding the right balance

It is important to consider the environmental issues in teaching and learning. However, it should not be a simplistic exercise. There is a wide range of options that need to be examined, not just on the energy consumption side of online technologies, but on all aspects of the way courses are – or could be – designed and the implications for energy consumption.

In terms of videoconferencing, it has its benefits but it should not be used – as during the pandemic – as a single, dominant mode of online delivery. We need to look at the following aspects of videoconferencing (you might like to add more):

  • what are the benefits and limitations (affordances) of both the audio and the video components of videoconferencing from the instructors’ perspective? 
  • similarly, what are the affordances of both the audio and the video components from the students’ perspective? 
  • what are the relative affordances of (a) synchronous (real-time) (b) asynchronous (recorded) uses of videoconferencing?
  • what are the benefits and limitations of videoconferencing compared to the use of a learning management system: what are each best used for?
  • what are the implications of videoconferencing for student privacy?
  • what are the cost implications, in terms of students, the institution, and the environment, of using videoconferencing for teaching and learning, compared to other methods, such as learning management systems or campus-based teaching?

Any one of these questions would make a good basis for a Ph.D. thesis, but I suspect the answers to these questions are more likely to evolve through practice and experience. But you can’t just look at costs; you also have to look at the benefits or the losses of using or not using a technology. Costs can always be reduced: but you have to look at the impact cost reduction has on quality, even, or especially, in an environmental context.

Over to you

If you have been using videoconferencing for teaching during the pandemic, I’d like to hear from you on the questions above.


  1. There have been studies on energy use in higher education teaching such as this one I was involved in: Caird, S., Lane, A., Swithenby, E., Roy, R. and Potter, S. (2015), “Design of higher education teaching models and carbon impacts”, International Journal of Sustainability in Higher Education, Vol. 16 No. 1, pp. 96-111. To quote form the abstract: The main sources of HE course carbon emissions were travel, residential energy consumption and campus site operations. Distance-based HE models (distance, online and ICT-enhanced teaching models) reduced energy consumption by 88 per cent and achieved significant carbon reductions of 83 per cent when compared with campus-based HE models (face-to-face and ICT-enhanced teaching models). The online teaching model achieved the lowest energy consumption and carbon emissions, although there were potential rebound effects associated with increased ICT-related energy consumption and paper used for printing.


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