Some years ago we examined the electricity costs of running a modern Home Broadband connection (here), which largely reflected the price of keeping your wireless internet router (or modem) switched-on around the clock. Given the issue of energy costs, we thought it might be worth seeing how this has changed.
Back in 2017 people were paying around 12 to 20 pence per 1 kWh (1,000 Watts per hour) consumed (daytime) and some setups also applied a cheaper nighttime rate, but to save time our estimates were based on the roughly middling rate of 15.5p (pence) per 1kWh of usage. We also opted to exclude the daily standing charge (currently c.53.35 pence per day), since it wasn’t directly connected to the amount of energy consumed by a router.
Since then, the cost of electricity has surged upwards at a shocking pace, although – mercifully – it has started to come down from the 2022 peak, due to a number of reasons that we aren’t going to explore today. The result is that many people have found themselves stuck on standard variable tariffs, which for the sake of argument – and based largely on the January 2024 energy price cap – will charge you around 28.62p per kWh of electricity used (varying between different regions, operators and plans).
The following thus represents somewhat of an updated view of the current costs, which looks at the consumption of the latest router models – those supplied by the biggest broadband ISPs – and also considers the impact of Optical Network Terminals (ONT or UNO), which are currently being installed as part of modern Fibre-to-the-Premises (FTTP) connections.
At this point it’s worth noting that some consumers may feel a desire to switch-off their routers at night to save power. But we’d generally caution against this due to the number of inter-dependent network devices that may be connected to a modern home network (e.g. security alarms, cameras, solar PV systems, mobile phones etc.).
In addition, most people still connect via broadband connections that involve some old copper wiring, such as ADSL, VDSL2 (FTTC / SOGEA) and G.fast. As a general rule, you should avoid switching these on and off a lot because the network operator’s Dynamic Line Management (DLM) system may detect it as a fault, which could drop your line speeds as the connection attempts to find more stability.
Router Features vs Performance
Hopefully it goes without saying that the amount of power a router draws will vary and is dependent upon both the device specification (chipset used, CPU performance etc.) and how much it’s being used at any given time (across WiFi, Ethernet links, firewalls etc.). For example, the WiFi service alone on your router may gobble anything from a few hundred milliwatts and up to 2-3 Watts at peak.
This is why most router manufacturers tend to specify figures for both IDLE consumption (i.e. when the device is operating but not doing much, such as when you’re asleep at night) and LOAD (i.e. when multiple devices are active on your network and moving data at fast speeds). The way manufactures define IDLE and LOAD figures can vary a bit (i.e. different methodologies for testing), but they’re still a reasonable guide.
Some people also use the Power Supply Unit (PSU) figures for routers as a gauge for understanding usage, but this is unwise as PSUs are designed to be able to cope with significantly more electricity than the device itself would typically use (plenty of overhead). In other words, don’t put too much stock in the old Volts x Amps = Watts calculation as a reflection of the router’s real-world consumption.
In addition, a router will only run so fast before you can’t do much more, and it ends up throttling the CPU (impacting your performance) or simply overheating, which may occur before the device itself reaches the max PSU rating. Supply and demand decisions can also impact the manufacturer’s PSU choice, which further divorces this part from actual device consumption.
In our summary we’ve opted to use official IDLE and LOAD figures, but where we couldn’t uncover the correct data we’ve used feedback from end-users to determine the likely consumption. All of these should be considered as estimates because we all use our networks in different ways.
Comparing Power Usage on Major ISP Routers
Before we get started, it’s important to consider the change in broadband value and thus efficiency. Modern routers have to cope with much more powerful and significantly faster WiFi, Ethernet and broadband connections (e.g. FTTC vs FTTP), but at the same time the chipsets and CPUs being used inside these devices have become much more energy efficient. Not to mention that the broadband connections themselves are also more efficient.
The above helps to explain, at least in part, why upgrading to a ten times faster internet connection than you had before doesn’t mean you’ll use ten times more electricity. In fact, even if the latest routers do use a bit more power than the models from 2017, you might still find that your overall electricity usage falls via other devices (e.g. computers) because you won’t have to leave them switched-on as long to conduct big downloads etc.
For example, TalkTalk’s old “Super Router” (HG635) from 2017 gobbled 6 Watts at IDLE and 10 Watts at LOAD. By comparison, the provider’s latest “Wi-Fi Hub 2” (Sagemcom F@st 5464) router consumes 7.29W at IDLE and 10.6W at LOAD, which is despite the fact that the latest model is much more capable than the older kit and is often used with faster broadband connections.
Click over to read page 2 and see the power and cost figures..