The ULiège Energy and Environment Unit is highlighting a number of actions to reduce your environmental impact in the office or when teleworking(1).
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Office hours (8-18h / 5 days a week) represent less than 30% of the total duration of a week. Any device (computer, printer, coffee machine, etc.) that remains on outside these hours represents a significant consumption and therefore pollution and CO2 emissions. It is therefore advisable to switch them off at the end of the day.
Example: a PC that consumes 100 W. If it is left on all year round (instead of during working hours) it represents an excess consumption of at least 615 kWh per year, i.e. 280 kg of CO2.
To make it easier to switch off these appliances, it is advisable to put all the devices together on a power strip and to switch it off at the end of the day. Even when switched off, the power supplies for the screens still consume some energy.
- The tabs in your browser in the background sometimes consume a lot of resources (especially the social networks). It is therefore advisable to close them if they are no longer in use.
- Streaming (playing an audio or video stream online) is one of the main consumption vectors in the digital sector. It accounts for more than 60% of data traffic on the Internet and approximately 20% of greenhouse gas emissions linked to digital uses, i.e. around 1% of global emissions (Source). It is therefore advisable to:
- Adapt the resolution of the video to the screen and to the use that is made of the video (and set these parameters by default if possible):
- There is no need to play the video in high definition on a smartphone, a resolution of 240p is sufficient;
- On a computer screen, a resolution of 720p is more than enough and can be reduced to 480p in the case of a training video;
- Prefer web radios to "video" playlists to listen to music.
- Mute the cameras (or adjust the quality of the video) during a video conference presentation if the video conference software allows it.
- Block automatic video playback on various platforms and social networks.
- Adapt the resolution of the video to the screen and to the use that is made of the video (and set these parameters by default if possible):
- The Carbonalyser extension (available for Chrome, Firefox and Android) allows you to estimate your environmental impact related to your internet browsing in order to become aware of it;
- Some search engines reverse the contrast (white/grey writing on a black background) to save energy. With the advent of LCD screens compared to the old CRT screens, this type of search engine no longer provides a significant gain (< 2%) on the screen's power consumption [Source]. Note that there are other search engines that donate part of their advertising revenue to social or environmental purposes (Lilo or Ecosia).
- Install a browser extension that blocks ads to reduce visual pollution and the "weight" of certain pages (e.g. µblock).
- For the most experienced users, it is possible to modify a file on your operating system (the host file) in order to make web pages lighter and reduce your internet traffic [Source].
An email consumes an average of 4g of CO2, especially as it is stored on a server that consumes energy.
- Avoid attaching large files.
- The institution offers a "FileSender" service from "Belnet" which allows you to attach files of up to 200 GB via a link in the email you write. In addition to being alerted when the file is downloaded, the attachment will be deleted from the server after a period of time that can be configured by the user.
- If the email is dedicated to internal people and if your department / service has a centralised file server, an alternative to the previous solution is to link to a file on the server.
- Reduce the number of recipients, especially if an attachment is sent.
- Once a year, delete superfluous emails (newsletters, etc.).
- To be effective, you can sort by date and size to delete only the oldest emails with attachments (deleting a 1 MB email is equivalent to deleting 200 5 KB emails[1].
[1] Typically a response email such as "ok" or "thank you
The institution offers an efficient internet access that is preferable to use (via WiFi if there is no wired connection[1]) instead of its 4G connection. Indeed, a 4G connection consumes almost 10 times more energy than using the internet via optical fibre [Source, Source][2].
[1] The wired solution is 10 to 20% more energy efficient than WiFi, depending on the study.
[2] Privately, 4G consumes about three times more energy than ADSL or cable
Whenever possible, use a bicycle (even an electric one) or walk to the office. These modes of transport reduce CO2 emissions per kilometre travelled by a factor of 7 to 10 compared to using a car. In the case of conventional buses, the reduction is about a factor of 3 [Source].
In the case of short trips within a site (Sart Tilman), it is also advisable to favour alternative modes (walking, cycling) where possible, as fuel consumption per km (and therefore CO2 emissions) increases slightly during the first few minutes of using a car. Moreover, during these first minutes of use, the catalytic converter which reduces many pollutants is ineffective because it is cold. The majority of the pollutants produced by the vehicle are then released directly into the atmosphere. Finally, during this period when the engine is cold (as well as its oil), it is less well lubricated and wears more.
The following links will give you more information on the walking and cycling routes in the Sart Tilman or the City. You will also find other useful information on these alternative modes of transport, such as where to park your bike (section "Where to park your bike").
- Replacing a dish without meat/fish (100g) reduces CO2 emissions by about 3kg per day [Source, Source].
- Use a water bottle, a solid lunch box, a lunch box or beeswax packaging to reduce waste (aluminium, plastic bags, etc.)
- Sort waste using the bins in the offices and buildings (PMC / cardboard / residual). Remember that the institution has set up several collection bins for used batteries and that WEEE (waste electrical and electronic equipment) is also collected.
- Bottled water generates 300 to 3000 times more CO2 emissions than tap water. Water fountains are and will be installed near most cafeterias and lecture halls.
- When you wash your hands, use cold water. In general, hot water will not arrive until you have finished washing your hands.
- Avoid leaving doors and windows open during the heating season (while respecting health recommendations - ventilate for a few minutes every two hours in rooms with little or no ventilation).
- Report a water leak (dripping tap, leaking toilet...) by making a request for intervention by selecting "Plumbing".
According to ADEME, 25% of printouts are thrown away after printing and 16% of printouts are never read. The production of one kilogram of paper (i.e. 200 sheets of standard paper weight) consumes around 60 to 100 litres of water and 4 to 5 kWh of electricity [Source], so it is worth being concerned and limiting printing.
- Only print if it is really useful. An alternative is to generate a PDF using PDF Creator;
- Activate the default "double-sided" option on the printers;
- Print in "draft" mode. Ink savings vary depending on the printer model;
- Consider printing 2 pages per sheet if reading is still comfortable;
- Buy recycled paper;
- Reuse single-sided printed sheets as draft paper;
- Optimise the layout of documents and/or remove unnecessary elements (email signatures / web page advertisements...) before printing;
- Recycle paper in the institution's dedicated paper bins as 90% of recycled paper will be reused for paper production;
- Unplug your printer, especially if it has the WiFi option activated (see electricity point)
If possible, try to keep your new equipment for as long as possible as it is usually subject to stricter consumption standards.
These items consume large amounts of raw materials and water, which should be used sparingly. For example, a pair of jeans requires 8,000 litres of water, a smartphone more than 12,000 and a car 75,000 [Source].
ADEME has also estimated the raw material footprint (excluding water) of many items of equipment. It can be seen that a smartphone requires around 220 kg of raw materials, although it generally weighs only around 300 grams, whereas a pair of jeans requires only 49 kg of raw materials for an average weight of 800 grams. These differences are mainly due to the fact that some ores (used in many electronic devices) are difficult to extract.
[1] This list is not exhaustive. Moreover, some of these actions are perfectly applicable to domestic use.