Saving energy around the home is a direct way that most people can spend less and have a positive effect on the environment at the same time. While it might seem obvious that new household appliances would be designed to use less electricity to run, this is not always the case. Here’s our guide to common devices and how much they could be costing you.
Charging your mobile phone
This is the most obvious culprit. Going back to the mid-1990s, mobile phones were relatively uncommon. They were expensive toys for the rich, or status symbols for business people. As the technology became cheaper, mobile phones became an essential item for almost everyone in western countries, and the phrase “I’ll text you” became more common than “I’ll call you later”. The launch of the iPhone in 2007 kicked it up to a whole new level, as true pocket-sized mobile computing became a reality.
While the old land line did use electricity, it was hard-wired into the phone line itself, so was paid for separately to the electricity bill. You may think charging a mobile phone can make a significant impact on the power budget, especially if everyone in the house has their own phone. In fact, it’s likely to barely cause a ripple, as smart phones often cost less than $1.00 a year in electricity, depending on the supplier, drawing less than 5kWh annually. While there are other energy impacts on mobile phone use, they don’t directly affect the phone owner (though they may affect the environment, as outlined in this article from Lifehacker– of course not everyone agrees, and there’s a counter-argument from thinkprogress.org here).
Device cost fact: A mobile phone often uses around $1 of energy in an entire year.
Using your desktop computer
Many homes have a desktop computer, and the amount of electricity this uses can vary widely. While some machines may use as little as 80 watts, high end machines can use 250W of electricity per year, as calculated by Griffith University. At an average of 28 cents per kWh, a low end machine (110w with CRT monitor) can cost as much as $90 per year if left on for 8 hours per day. Adding the cost of the printer, scanner, speakers and other peripherals, and the bill can easily tip over $100 per year. Of course, the easiest way to bring this cost down is to turn off the computer when not in use.
Device cost fact: An low spec desktop computer can use over $90 per year in electricity if on for 8 hours per day (28c per kW/h)
One of the most enduring myths about electrical devices is that turning them on again uses substantially more electricity than leaving them on. This is not true of almost every device in domestic use. With modern computers being replaced regularly, turning them off and on again poses very little risk of wearing them out before the need to upgrade.
Device cost fact: It’s cheaper to turn off devices when not in use.
Turning things off at the wall is always better, but computers invariably have a sleep mode that allows faster start-up after a period of inactivity. These standby settings use much less electricity than a computer left fully turned on all the time. In general, Mac computers use a comparable amount of energy to PC based systems, as processors and components don’t differ greatly “under the hood”, at least according to the figures from UPenn.edu shown here.
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Powering your laptop or notebook
Laptops and notebooks are generally much more efficient devices than desktop computers. They are designed to run on battery power, and so in many cases the processor and other hardware is less powerful than a desktop model. The energy usage comes in between 25 and 60 watts in most cases. A low power machine works out to be around $20.45 per annum for 8 hours use per day, 4.4 times less than running a desktop. It’s clear that in the energy stakes, laptops beat desktop computers hands down. There is an argument that laptops are more expensive to repair should they break down, and buying a laptop as the main home computer may end up costing more. This may be true, but often only a small fraction of laptops break down, so the energy saving could outweigh potential repair costs.
Device cost fact: An average spec laptop uses $20.45 per year in electricity if on for 8 hours per day (28c per kW/h)
There is a lot of variation between makes and models, with laptops running optical disk drives and physical hard drives using a lot more energy than those based on flash memory with no optical drive (aka netbooks). Using Wi-Fi and Bluetooth capabilities will also draw a lot more power as constantly transmitting a signal is an active function. As with desktops, you’re very unlikely to wear out your computer by turning it off when you are not using it before replacing it altogether.
Using a tablet
With the advent of tablet computers, some may have expected to see a rise in energy bills, just as with smart phone charging. In fact, as with the smart phones, tablets use very little electricity to run. With no moving parts and highly efficient components, as well as limited processing capacity, the energy requirements of tablets are very low.
Device cost fact: An iPad costs around $3.50 per year if charged every other day.
An average tablet uses 15 watts of power, which equates to around three cents per day if plugged in for 8 hours. An iPad uses even less as 12kWh of electricity per year as discussed in this article from cnet. That means that an iPad may only cost around $3.50 a year to keep running, even if you completely use the battery and charge it every other day. Assuming you are not also running a laptop and desktop simultaneously, that can be a significant saving.
Playing a gaming console
Early home computer game consoles like the Atari, and the later Nintendo systems used relatively little electricity, as they had very limited processing power and no moving parts. Modern consoles are much more powerful stand-alone gaming computers, and can potentially make a huge dent in the electricity usage of a household, especially when combined with large screen TVs and other peripherals such as surround sound systems. Even among the consoles, the energy usage varies widely, from the power hungry PS4 at 90-150W to 40W for the Nintendo Wii. Depending on how much the console is used over the course of a year, this can really add up – especially combined with the energy used by the TV, which on its own could easily hit $64.00 per year (a 6 star rated LCD screen measuring 150cm, on for 5 hours per day).
Device cost fact: Calculating appliance power costs is easy with this tool from Switch On.
The Wii U has the lowest electricity use, at only 35 watts which works out at a little over $3.50 per year if used for an hour a day, while the PS3 is the highest of the current machines at 190kWh, with the original model of the Xbox 360 about the same. That works out to be almost $20.00 a year if used only an hour a day, which isn’t much for some households. Interestingly, the PS4, despite being a more powerful console, is claimed to top out at 150 watts. In many cases the newer versions of consoles have focused on reducing power usage, but this may not reflect the reality as explained in this Kotaku article.
It’s worth remembering that games consoles can also draw power when switched off, for example the PS4 uses 10 watts even when it’s on standby. That means it’s costing almost $25.00 a year even without being used unless it’s turned off at the wall (23 hours per day at 28cents per kWh). You can see the cost comparisons here and even calculate the daily cost.
Device cost fact: If combining the console, TV, sound system and internet connection, gaming could be the most power-hungry activity in the home.
It’s not always intuitive to know what uses the most electricity around the house, and the gadget’s importance does not necessarily reflect the drain on electricity. With better understanding of the real costs of using our favourite devices, you could make better decisions when trying to save energy.