Zoom Vs Vroom

Contributor Vilnis Vesma explores the very topical subject of the last year of working - the transition to online meetings for many organisations. As the country opens up from the Covid restrictions, questions are arising on whether we can maintain the trend for online working to support environmental sustainability as well as flexible working (and the benefits of a reduction in commuting!). We came across the following article which we found a useful basis for arguing the case.

Loyal reader Paul C. asked if I'd ever seen any articles about the climate impact of remote meetings, and I hadn't, so I decided to work it out for myself. Here's the comparison of emissions from remote meetings with those from travelling to attend in person...

We'll start by estimating the energy intensity of data communications. We know from an Ofcom study that in 2018 the average UK fixed broadband connection was using 240 GB per month, and if we assume £30 per month was the typical tariff, that works out at £0.125 per GB. Now let's assume that this price covers the operator's costs and that, pessimistically, 50% of that cost is for electricity which they were buying at (say) £0.15 per kWh. This implies an energy intensity of £0.125 x 50% / £0.15 = 0.42 kWh per GB.

But how much data is there in a remote meeting? Fortunately, we can get a good direct estimate from the sizes of session recordings. My two-hour on-line events have typically resulted in recordings of around 500 MB, which must be the equivalent of all the data broadcast to each participant (as a sense check, that's 250 megabytes per hour, or about 0.55 megabits per second bandwidth). To be conservative let's add as much again for return traffic from each participant, giving a total of 500 MB (0.5 GB) per hour per participant.

At 0.42 kWh per GB that implies 0.5 x 0.42 = 0.21 kWh per participant-hour.

This only accounts for the communications element. To be fair we need to add the cost of central data processing and to do that I'm firstly going to guess that the server consumes 100 watts for the purposes of processing the meeting. Secondly, I'll assume that the meeting has four participants. That would imply 0.025 kWh per participant-hour, bringing the total to 0.235. The fact that it's a small correction means the conclusions aren't very sensitive to the number of participants. If we assume a grid carbon intensity of 0.3 kgCO2/kWh we arrive at emissions of 0.235 x 0.3 = 0.07 kgCO2 per participant-hour.

How does that final figure compare with car travel to the meeting? The average car in the UK emits about 0.12 kgCO2 per km, so attending an hour-long remote meeting equates, in emissions terms, to 0.07/0.12 = 0.58 km of car travel. Case closed.

With thanks to Vilnis Vesma who runs the Energy Management Register bulletin and gave permission to reproduce this article.

For more useful blogs and energy management information the bulletin can be accessed via: http://vesma.com/subscribe

Please note: the views expressed in this blog are those of the contributing individual, and are not necessarily representative of the views of IEMA or any professional institutions with which IEMA is associated.