Your favourite laptop may be an extension of who you are as a person. It brings you so much happiness and fulfilment. Or you might see your laptop as a trusty workhorse that helps you to deliver your projects efficiently and effectively. Either way, you might never have considered the question: how many watts does a laptop draw?
Whether you’re gaming, streaming, or just using a MS Office application, your laptop is lowkey adding to your electricity bill. We break down how much power a laptop uses to get a better handle on what it means in rands and cents. We also offer a score of helpful tips so that you can use your laptop smartly while still enjoying all the delights it offers.
Energy Usage – How Much Power Does A Laptop Draw?
You probably won’t be surprised that there’s no single answer to the question. The power consumption of a laptop varies greatly depending on a bunch of factors. Model and make play a key part. A powerful gaming laptop with top-of-the-line components guzzles more charge under load than a Chromebook with a low-power CPU.
Hardware specifications, software applications, usage patterns, screen size, and power settings are all factors that impact power usage.
On average, a typical laptop’s power consumption while on charge ranges from around 30 watts to 100 watts.
During light use such as web browsing, word processing, or even watching videos, the power consumption is usually closer to 30-50 watts. When the laptop is driven hard by a gamer in a furious fire-fight or on a rendering task, the draw can increase to 70-100 watts. It may rise even higher; a high-performance gaming laptop can draw up to 200 watts!
Manufacturers have done a great job in driving down laptop energy needs while upping performance. The best modern laptops and gaming computers are stylish, hardworking, and energy efficient!
Understanding The Cost Of Laptop Power Usage
The 30-100 watts mentioned above represent the laptop’s power usage under different load conditions. These values are typically measured as the average power consumption during operation.
To calculate the energy consumed in watt-hours (Wh) over an hour, you multiply the average power consumption (in watts) by the number of hours:
- Assuming an average of 40 watts consumption: Energy (Wh) = 40 watts × 1 hour = 40 watt-hours
So, the laptop would use 40 watt-hours of energy in an hour if its power consumption remains constant at 40 watts during that time. However, we’ve agreed that laptop power consumption can vary.
What does this mean in rands and cents?
Using a rounded 300c per kWh for the cost of electricity and assuming you use your device at a constant performance level for 8 hours.
Laptop power consumption per hour (kWh) = 40 watts / 1000 = 0.04 kWh (electricity is charged in kWh).
The calculation is 0.04 kWh (hourly consumption) x 8 (hours used) x 300c (electricity cost per kWh)= 96c. Call it R1 daily – R30 a month assuming a constant use pattern every day.
Comparing the Power Usage of Laptops vs Desktop Computers
Laptops generally need less power to operate than desktop computers. That’s to be expected since laptops are slim and sleek beasts in comparison. Your average laptop screen is smaller and has a lower power rating than the average desktop monitor. Laptops mostly have slightly lower processor speeds too.
A desktop computer will typically have larger and less energy-efficient components. Laptops have lower-power CPUs and GPUs which translates to lower electricity usage.
Desktop power usage can range from 100 to 500 watts depending on configuration and usage. A gaming desktop uses 450-1,000+ watts. Compare that to a gaming laptop where draw doesn’t usually exceed 300 watts.
Overall, it’s estimated that laptops use 20-50% less power than comparable desktop computers.
Modern tablets, on the other hand, use closer to 10 watts.
How To Use Your Laptop More Energy Efficiently
It’s a fair bet we don’t all use our devices as energy-efficiently as we could. There are loads of ways to be smarter regarding laptop power use. Let’s dive into a few efficiency tips:
- Power management settings: Using power saving mode is a great start. You can use Windows Power Saver or Balanced power plan, which should be available in the Control Panel or Settings. On macOS, System Preferences > Energy Saver should allow you to adjust the settings accordingly.
- Screen brightness: The screen display is one of the most power-hungry components on the machine. Look to lower the screen brightness or use the adaptive brightness feature. This adjusts the brightness based on ambient light conditions.If you have a colourful background you could replace it with a blank screen or something with darker colors. You probably don’t want to be a (minor) energy-saving hero here if it’s going to harm your eyesight though.
- Screen timeout: Set a shorter screen timeout so that the display turns off when not in use. It’s also good practice to set your device to enter sleep or hibernate mode when it’s idle for a certain period.
- Close unnecessary applications: Some applications, especially resource-intensive ones, are power-thieves even when they’re minimized. Close any background applications or processes that you are not using. Also, disable unnecessary startup apps which tend to consume system resources and power.
- Use integrated graphics: If your laptop has both integrated and dedicated graphics cards, switch to integrated graphics when web browsing or word processing. Dedicated graphics cards consume more power and are usually only needed for graphics-intensive applications like gaming or video editing.
- Keep the machine clean: When your laptop overheats the system is likely consuming more power to maintain performance. It’s important to try and keep especially the cooling system clean and free from dust.
- Update software and drivers: Keeping your operating system, drivers, and applications up to date generally improves efficiency and reduces unnecessary power usage.
- Eject external devices: External devices such as USB drives or external hard drives draw power from the laptop. It’s best to disconnect any unnecessary external devices when not needed.
What Laptop Components Use the Most Power?
Let’s look at the heavy power hitters within the laptop. The components responsible for drawing the most power are the dedicated GPU (Graphics Processing Unit) if the machine has one, the CPU (Central Processing Unit), and to a lesser extent the display.
- CPU: The CPU effectively runs all software and applications. Depending on the number of cores, the power usage of the central processor spans from 50 to 150 watts. When you use applications that require plenty of processing power – think video editing software or 3D modelling – the CPU will consume hungrily.Some modern CPUs are designed to adjust their clock speed and voltage based on the workload. This potentially also kicks up energy consumption.
- GPU: The GPU is responsible for rendering graphics and performing tasks related to image and video processing. Integrated graphics which are part of the CPU use less power. But dedicated GPUs are known to be pretty power-hungry when performing graphics-intensive tasks like gaming, video editing, or running machine learning applications.A low-end GPU can use from 30 to 80 watts and a high-end GPU up to 200.
- Display: A 16-inch screen may use up to 60-70 watts per hour. A larger or high-resolution screen will consume even more. The brightness level and refresh rate also influence power usage.
Other components also contribute to power consumption but not as heavily:
- RAM: Random Access Memory itself doesn’t consume much power (around 3 watts for every 8GB of DDR4 or DDR3 memory). More RAM is a definite advantage. Increasing the RAM should allow the CPU and GPU to work more efficiently.
- Storage: Solid State Drives (SSDs) are considered more energy-efficient than traditional Hard Disk Drives (HDDs) since they have no moving parts. However, the storage drive’s power consumption is typically under 10 watts and is a relatively small change compared to the CPU and GPU.
- Wireless Features: Wi-Fi and Bluetooth modules consume power especially when actively searching for networks
- Cooling System: The laptop’s cooling system includes fans and heat sinks and also needs its share of power. When the CPU and GPU are under heavy load, you can bet the cooling system is working harder to dissipate the heat.
Using Battery Power
You can save perhaps 10-20% by using your laptop on battery power for part of the day. This works best when you’re only doing light tasks.
When the laptop is plugged into the socket, it’s drawing power to run the device. It’s also charging the battery at the same time. Unplugging the laptop reduces demand slightly.
Remember though that while using the laptop on the battery does save some power, your overall consumption depends on how you’re using it. If you upload and start editing video, the battery is sure to run down fairly rapidly.
To be kind to your battery and extend its life:
- Use the battery-saving mode options available on your system.
- You don’t want to charge your battery to 100%. There is a consensus that continuously charging your battery to the max could shorten its life.
- A good guide is to operate with a charge of between 50% and 80%. Plug the laptop in when you get the low-battery alert. Try and remember to disconnect when you’ve charged 80-90%.
- Shut your machine down completely at the end of the day.
How Does Laptop Power Usage Compare With Other Appliances?
The power consumption of a laptop is generally lower than that of many other household electrical appliances. It’s useful to have a rough understanding of your laptop’s power demands relative to other common electrical devices. Here are approximate comparisons:
- LED/LCD TV: Modern LED or LCD TVs are more energy-efficient than older models. The average power consumption for a mid-sized (40-60 inches) LED/LCD TV is around 50 to 100 watts.
- Microwave Oven: Microwave ovens typically consume around 600 to 1500 watts during cooking. Electric stove/ovens can use over 2000 watts.
- Fridge: Consumption for fridges runs a range from around 200 to 800 watts depending on size and efficiency.
- Air Conditioner: A/C power consumption runs from 500 watts for smaller units to 3000 watts or more for larger central air conditioning systems.
- Washing Machine: Smaller front-loading machines usually consume around 300 to 500 watts, while top-loading machines can easily use over 1000 watts.
- Tablet: 5w – 20w.
- Smartphone charge: 5 watts, often less.
How long does a laptop last?
A good quality laptop, used daily, can last between 2 and 5 years. If you treat your laptop well, you can expect it to last a lot longer than that.
How can you measure a laptop’s power consumption?
You can use various software tools to monitor power usage or invest in a power meter to measure real-time power drawn from your laptop’s power adapter.
What does laptop wattage mean?
Laptop wattage refers to the maximum power consumption of the laptop. Though, laptops don’t typically operate at the peak of their maximum power consumption.
How do you know how power-hungry your laptop is?
To get an idea of how power-hungry -or not- your laptop is, you can usually find the information in the laptop’s user manual. You can also check the power adapter’s specifications which should indicate the maximum power output in watts.
What is a watt-hour?
A watt-hour is a unit of energy that measures the energy an item consumes over a time period. It is used to measure the amount of output generated.
We’ve seen that power consumption varies widely based on the specific laptop model, its hardware components, usage patterns, and the settings used. There are many power-saving features, settings, and tips you can employ to reduce the overall energy consumption of your machine.
Know, too, that manufacturers are continuously working to improve energy efficiency from their side. Newer laptop models will often feature more power-efficient CPUs and GPUs.
PC International presents an awesome selection of new sleek, stylish, and efficient laptops, notebooks, and gaming devices. Be sure to follow PC International’s offerings to stay current and not miss out on the latest in exciting rewarding tech.
Sources:Wattage Of A Laptop – Are Laptops More Energy-Efficient? (2023) (makemesustainable.com) How Much Power Does a Laptop Use? (Answered!) | DeviceTests/ How Much Energy Do My Appliances Use? INFOGRAPHIC (smarterbusiness.co.uk) Electricity usage of a Laptop or Notebook – Energy Use Calculator capetown.gov.za/Family and home/residential-utility-services/residential-electricity-services/the-cost-of-electricity