8 Ways to Save Power in Your Raspberry Pi Projects (2024)

Although the Raspberry Pi is a very power-efficient computer, there are specific scenarios where you may want to drive power consumption even lower. One of these is if you are using a power bank or an uninterruptible power supply (UPS) to supply electricity to your Raspberry Pi. Decreased power consumption can also be useful if you are running an always-on project, and you need to keep your energy bill as low as possible.

Understanding the Raspberry Pi's Power Consumption

Thanks to its ARM-based architecture, the Raspberry Pi is a very low-power device. The Raspberry Pi 4 uses 2.7W while idle, according to tests by Jeff Geerling. In comparison, the most efficient x86 computer will consume 10W to 25W, significantly more than what the Raspberry Pi uses operating under 400% CPU load, 6.4W.

This all serves to drive home the point that the Raspberry Pi is already not making a significant impact on your energy bill, at least compared to your other gadgets and devices. So, further decreasing power consumption on a Raspberry Pi may be a waste of time and effort if your project does not require it.

However, if energy efficiency is crucial to your project, down to the last milliwatt, then the tips described below will be helpful to you.

1. Run a Headless Setup

A headless setup is a common way of running a Raspberry Pi, and it involves using the Pi without a keyboard, mouse, or display connected. Since not all projects require a display or any of those, a headless setup is a good way to reduce the power consumption of your Raspberry Pi setup.

All you need is a separate computer and an internet connection (either via Wi-Fi or Ethernet). Once SSH is enabled on your Raspberry Pi and both computers are connected to the same network, you are good to go. You can then use a command-line terminal or an SSH client such as PuTTY on your other computer to issue remote commands to the Pi. VNC is another option if you prefer working with a graphical user interface (GUI)

2. Remove Unneeded Peripherals

You don’t have to run your Raspberry Pi headless all the time. Simply disconnecting peripherals when they are not needed will reduce power consumption. Keyboards, mice, and storage devices all consume power, even when not in use.

Wireless devices typically use slightly less power than wired ones. Most USB mice and keyboards use around 0.5W of power per hour, and this figure increases when they’re in use. While this figure might not seem like much, it tends to add up over time.

Another thing to keep in mind is that hard disk drives (HDDs) typically consume much more electricity compared to solid-state drives (SSDs). So, if you are trying to save as much electricity as possible, opt for an SSD or SD card instead. SSDs offer several other advantages over HDDs.

3. Disable the USB and HDMI Ports

Although unused ports draw a small amount of power, you may want to disable them if you're trying to save as much power as possible. When disabling USB, you should note that you can’t disable ports individually. All the ports get turned off when you disable USB.

Also, turning off the USB controller disables Ethernet, since they share the same data bus on the Raspberry Pi. Disabling USB will save about 100mA.

To disable USB on the Raspberry Pi 3B+ and earlier models, enter the following command in the terminal:

echo'1-1' |sudo tee /sys/bus/usb/drivers/usb/unbind 

To re-enable the controller, simply change the unbind in the last command to bind.

Also, you should disable HDMI if you are running a headless setup. This will save about 25mA, adding up to 125mA in total. To turn off HDMI, run the following command:

sudo /opt/vc/bin/tvservice -o 

To turn it back on, all you need to do is change the -o to -p in the last command.

You should however note that if you follow the steps described above, USB and HDMI will be re-enabled when you reboot the Raspberry Pi. But, you can add the commands to the rc.local file to run them on startup. To learn more, check out our list of three ways to run a Raspberry Pi program at startup.

4. Disconnect the Power Supply When Not in Use

A common mistake is to leave the Raspberry Pi connected to a power source when it is not in use. Even when shut down, the Raspberry Pi continues to draw power, between 0.1W and 0.15W. Be sure to remove the Raspberry Pi from the power supply when it is not needed.

5. Slow Down the Processor

Underclocking the Raspberry Pi’s CPU makes it run at a slower clock speed but reduces its power consumption and may be useful for battery-powered, portable projects that don’t involve complex processing. This follows a similar process to overclocking your Raspberry Pi.

Just navigate to the /boot folder, open config.txt, and change the preset clock speed, 1.5GHz for the Raspberry Pi 4. To underclock your Raspberry Pi down to 1GHz, you would add these lines to /boot/config.txt:

arm_freq=1300
arm_freq_max=900M/code> 

6. Disable the Onboard LEDs

The Raspberry Pi 4 has four onboard LEDs: two next to the GPIO header and two on the Ethernet port. Disabling them saves around 2mA and is as easy as editing the config.txt file. However, the commands are a bit different, depending on the Raspberry Pi model.

For the Raspberry Pi 4, simply edit the /boot/config.txt file and add the following parameters:

# Disable the PWR LED
dtparam=pwr_led_trigger=none
dtparam=pwr_led_activelow=off
# Disable the Activity LED
dtparam=act_led_trigger=none
dtparam=act_led_activelow=off
# Disable ethernet ACT LEDs
dtparam=eth_led0=4
# Disable ethernet LNK LEDs
dtparam=eth_led1=4 

For the Raspberry Pi 3B+, the last few lines to turn off the Ethernet LEDs are a bit different.

# Disable the PWR LED
dtparam=pwr_led_trigger=none
dtparam=pwr_led_activelow=off
# Disable the Activity LED
dtparam=act_led_trigger=none
dtparam=act_led_activelow=off
# Disable ethernet ACT LEDs
dtparam=eth_led0=14
# Disable ethernet LNK LEDs
dtparam=eth_led1=14 

7. Optimize Your Code

If you are running programs that you wrote yourself, you should ensure that you avoid certain bad practices that can impact power consumption. You should keep processing to the barest minimum needed to get the job done. Limit loop iterations, simplify operations as much as possible, and prioritize functionality over design in applications.

8. Use a Pi Zero or Pico Instead

This will most likely result in the most drastic reduction in power consumption. The Raspberry Pi Zero 2 W is the most power-efficient Raspberry Pi, according to Hackaday. It is capable of running faster and completing more tasks per watt of power, compared to other Raspberry Pi models.

The Raspberry Pi Pico is a microcontroller based on the RP2040 chip, and it offers the lowest power consumption of a Raspberry Pi board. The popcorn media player demo described in the Raspberry Pi Pico datasheet (VGA, 4-bit SD card access, and I2S audio) consumes about 0.45W of power. It also has two power-saving modes that decrease power consumption even further.

If your project doesn't require considerable processing power, consider using the Raspberry Pi Pico or Zero instead of the more powerful models.

Limit Power Consumption in Your Raspberry Pi Projects

As mentioned, the Raspberry Pi is already a very power-efficient device and there isn’t a lot you can do to minimize power consumption further. However, in power-critical applications where every milliampere counts, disabling ports and interfaces you don’t need will help you save power and keep your Raspberry Pi on for as long as possible.

If you make too many changes or want to reset your Raspberry Pi to the initial settings, all you have to do is flash a new version of the Raspberry Pi OS on the SD card.