From an energy perspective, in using a digital device, there are four things to consider:
- The wattage of the device
- The length of time the device is being used for
- Electricity source
- Battery management
The higher the wattage, the more energy. A typical smartphone will have a wattage of three, which means that using that smartphone at maximum power for an hour will consume three watts of electricity. A typical laptop will have a wattage of 40-60. A typical desktop can have a wattage of 200 watts or more, not including the screen. A 20” screen can have a wattage of around 20 watts, a 30” screen, around 40 watts. Thus, doing a task on a desktop can use up to 80 times more electricity than doing the same task on a smartphone. So, the guide is to always try and use the device that consumes the least wattage, which in reality means trying to use the smallest device, particularly the device with the smallest screen, as screens are often the single greatest users of energy. (The processor is also a big user of energy. The noise of the fan whirring means that your device is working hard and consuming lots of energy.)
The amount of energy consumed while using a device will depend at least to some degree on what you are using it for. So, for example, if you are doing heavy processing or streaming a high-definition video, you will be consuming more energy than if you are writing some text emails. However, it’s not quite as simple as that. A 200-watt desktop computer that is on but not being used is still likely to be consuming about 100 watts. At 50% utilization, that will increase to around 180 watts. The final 50% only consumes an extra 20 watts. There is an important rule here: turn stuff off when you’re not using it. Humans are monumental wasters. As much as 20% of electricity that gets into a home or office is wasted. This ‘vampire power’ is being consumed by devices that are on but not being used.
A facile argument by network providers is that you can send and download as much data as you want because their systems are designed to be always on, always consuming electricity and causing CO2 even when there’s zero data going through them. This is like deciding that you’re going to keep your oven on 24/7 and then thinking that it doesn’t matter how much stuff you now cook in it because it’s ‘always on’. Of course, in the network world they keep telling us that we must move from 1G to 2G to 3G to 4G to 5G; these always-on systems always need these huge investments in upgrading because the quantity of data going through them is exponentially growing due to our growth-at-all-costs business models.
To avoid the always-on power vampire:
- Get the monitor to go off as quickly as possible if it’s not being used. (Have it go off in a couple of minutes, and certainly no more than five minutes.)
- Have the device go to sleep / hibernate after about five minutes of non-use and certainly no more than 10 minutes of non-use.
- Shut off any device that is not being used for an hour or more.
- Shut down / switch off everything at night. Get power strips as that will make it easier to switch multiple devices off at the same time.