With energy costs rising and increased focus on protecting the environment, many people are questioning the logic of leaving their modem powered on all the time. Is turning off your modem when not in use a good idea? We tested it for energy saving and consulted with a telecommunications expert to get his feedback.
Turning off your modem every night does more harm than good. It would save you less than $1.00 monthly in energy costs while negatively impacting your internet performance. Modems use less than 15 watts of power and were designed with 24-hour operation in mind.
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How Much Electricity do Modems Use
The vast majority of modems use between 5 watts and 15 watts of electricity to operate. Some older modems use as much as 15 watts, while most modern cable or DSL modems use around 10 watts of power or less.
To find out how much power modems use, we decided to conduct a mini-experiment with several of the most popular models.
| Manufacturer | Modem Type | Model Number | Power Consumption in Watts |
| Motorola | Cable | MB8600 | 9.35 |
| Motorola | Cable | MB7621 | 8.82 |
| Motorola | Cable | MB7420 | 9.54 |
| Arris | Cable | SB8200 | 10.98 |
| Arris | Cable | SB6190 | 10.76 |
| Arris | Cable | SB6183 | 9.87 |
| Netgear | Cable | CM2050V | 12.93 |
| Netgear | Cable | CM1200 | 10.44 |
| Zyxel | Cable | BRG3550 | 9.52 |
| Linksys | Cable | CM3024 | 8.13 |
| D-Link | DSL | DSL-520B | 5.46 |
| Actiontec | DSL | C2300A | 6.27 |
| Arris | DSL | NVG443B | 6.10 |
The highest wattage of any modem we tested was just under 13 watts and some modems were as low as 5 watts. The average was right at about 10 watts.
How Much Will Turning Off Your Modem Save in Electricity Costs
The cost of electricity varies greatly by location. For this reason, we will do 3 estimates one with prices on the lower end, one with average prices, and one with higher-than-average prices.
Scenario 1: Average Electric Rates
According to the Bureau of Labor Statistics electricity currently averages about $0.17 per kilowatt-hour kWh.
Assuming your modem uses 10 watts of energy, the cost to run your modem 24 hours per day is $1.22 per month in electricity costs.
If we turn the modem off for 8 hours per day at night, we will save $0.41 monthly in electricity costs. That works out to about $4.90 per year in savings.
Scenario 2: Below Average Electric Rates
If our electric rates were at $0.12 per kWh as is common in the pacific northwest region, our savings would be even less.
Assuming your modem uses 10 watts of energy, the cost to run your modem 24 hours per day is $0.86 per month in electricity costs.
If we turn the modem off for 8 hours per day at night, we will save $0.29 monthly in electricity costs. That works out to about $3.46 per year in savings.
Scenario 3: Higher Than Average Electric Rates
Some regions, including the northeast region of the United States, have much higher than average electricity costs.
If our electric rates were at $0.24 per kWh, our savings would be slightly higher.
Assuming your modem uses 10 watts of energy, the cost to run your modem 24 hours per day is $1.76 per month in electricity costs.
If we turn the modem off for 8 hours per day at night, we will save $0.58 monthly in electricity costs. That works out to about $6.91 per year in savings.
Is Turning Off Your Modem Worth it for Energy savings
Only you can decide that for yourself. Given that the average savings work out to less than $5 per year, I would have difficulty recommending this as a means of saving on electric costs. Swapping out incandescent light bulbs for LED, cleaning your furnace filter, and other simple changes can save you far more than turning off your modem.
| Modem Wattage | Energy Cost per kWh | Saving Per Year |
| 5 | 0.16 | $2.34 |
| 5 | 0.24 | $3.50 |
| 10 | 0.16 | $4.67 |
| 10 | 0.24 | $7.00 |
| 15 | 0.16 | $7.00 |
| 15 | 0.24 | $10.51 |
Impacts on Internet Performance
Turning off your modem every night can negatively impact your internet performance. This is especially true with DSL modems. When you turn your modem off, it forces a re-sync with your ISP. When this happens over and over again, many systems will automatically switch to a lower connection speed in an attempt to maintain the connection.
Modems are designed to be always on devices, they do not benefit from getting turned off apart from a rare reboot for firmware updates.
Most of the major internet service providers, including Comcast (Xfinity), Spectrum, Cox, AT&T, and Verizon Fios, all recommend keeping your modem on at all times for the best performance.
Impacts on Firmware Updates
Modems, like other networking devices, rely on firmware that needs periodic updating. Generally, ISPs automatically push these updates in the middle of the night when the impacts are going to be felt by the fewest customers.
For this reason, you are best off keeping your modem powered on overnight and letting firmware updates happen automatically as your ISP intends.
Impacts on Modem Lifespan
There is limited data available on whether turning off you modem every night will shorten its lifespan. The general opinion of most engineers is “probably”. It is also worth noting that non of the manufacturers recommend turining off your modem at night.
Whether, this is critical or not is not stated. However, given that msot modems cost between $75 – $400, it might not be worth taking any chances here in an attempt to save about $5 per year in electricity costs.
Impacts on Your Devices
If you power of your modem all devices that rely on that modem for intetnet will drop offline. Devices such as smart bulbs, and WiFi security cameras will not function with your modem unplugged. Devices with cellular functionality including your smartphone will automaticlly switch over to cellular data.
This means that anything that get downlaod or uploaded at night will count against your monthly data plan limit. For this reason alone, turning off your modem at night makes little or no sense. Of couse if you are one of the few people remaining on plannet earth that shut their phone’s off at night, and have no IoT devices, perhaps this doesn’t apply to you.
Even then, do you really want to have to turn your modem on each morning and wait up to 5 minutes for it to come online?
Is it Bad to Turn Off Your Modem Every Night
Yes, it is bad to turn off your modem every night. Doing so not only can shorten the lifespan of your modem but can also affect your internet performance. Modems are designed to be left turned on 24 hours per day. It is not advisable to turn your modem off every night.
Turning off your modem at night offer little benefits in terms of energy savings. Modems simply do not use much energy to run.
Much like routers, modems are designed to be low power devices that reamin on all the time.