Most elements in nature gradually wear down as they age. Computers are no different, what with all the different internal components working together.

But our devices don't just slow down or become more likely to break over time---sometimes they seem to use more power. Is that actually true? Why might this be the case? Here's everything you need to know.

How Much Power Does Your Computer Use?

Using a computer for as long as possible seems like a smart idea: You extend the life of your purchase, getting more bang for your buck. You also reduce how quickly discharged electronic parts end up in a landfill or ocean.

However, there's always a but. In this case, keeping an old PC around as your primary work machine, or even turning it into a home server, can actually cost you more money over time.

This is due to energy usage. A computer could use a substantial portion of the electricity in your home, especially if it's running all the time and unable to go to sleep.

If your power is coming from a power plant that burns fossil fuels, then you're neither doing your wallet or the environment any favors by keeping that PC running. A report from the Natural Resources Defense Council details how computers account for a substantial portion of global electricity usage.

The typical desktop machine can use around 100-200 Watts. If you're using high-end components and regularly strain your PC with intensive tasks (such as gaming or video editing), then your own numbers could be much higher.

Fortunately, there are ways to determine how much power your machine is using. If you don't want to fiddle with software, you can buy an electricity usage monitor to plug your PC into.

Why Computers Might Use More Power as They Age

We expect our computers to deteriorate over time, but they don't always age in the way we expect. And some of the problems that cause your PC to run more slowly also play a part in why it ends up using more power.

Want to know why your old PC is pulling more current than it used to? Here are some of the potential causes:

  • Outdated technology. If you have a CRT monitor, it's sucking up more power than a comparable LCD or LED. An old Pentium CPU tower is less powerful than a Raspberry Pi and takes more energy just to boot up.
  • More demanding software. A PC that's a been around for a decade or two was designed in a time before you could stream all of your favorite shows in 1080p. It may have handled Shockwave video without breaking a sweat, but now it struggles just to load modern banner ads. When your computer is working this hard, it's using more power.
  • Not enough RAM. RAM is often the area where older machines fall short first. If your computer doesn't have enough RAM, it turns to other parts of the computer to compensate. A spinning hard disk requires more energy than a RAM stick, and it delivers slower results.
  • Dust accumulation. Dust can damage components. It can also collect on the heatsink. This causes your computer to overheat. Your CPU must then throttle itself (i.e. run slower) to avoid damage. Your cooling system, typically a fan, must then run harder and longer, sucking up energy.
  • Low-quality components. Manufacturers may use thermal paste that doesn't hold up well over time. As this paste degrades, the CPU runs hotter. Then you face throttling and forced cooling increases, like with dust build-up.

Why Mobile Devices Stop Holding a Charge

Laptops, mobile phones, and tablets have shorter lifespans than desktop PCs. Many of us only anticipate using a phone for a couple of years, tops. Technology doesn't change so quickly that our next phone uses drastically less power than our last.

But it's still the case that aging mobile devices don't hold a charge as long as they did when they were new. Much of this has to do with the nature of lithium-ion batteries. These batteries have a limited number of charge cycles. Plus, even if you were to keep a battery unused on a shelf, it would still only last around two to four years.

What to Look For in Replacement PC Parts

Let's say you're ready to send your computer off to retirement. How do you avoid buying a machine that's only going to guzzle more fuel?

This is mainly a question of priorities. Spec sheets often emphasize screen resolution, processors, and graphics cards, but going with larger numbers also means using more power. If you don't need the extra capacity, then you're using more energy than you need to accomplish your tasks.

Here are some ways to save money over time:

  • Only get the specs you need. It may seem tempting to get an i9 processor over an i5, but if you're only using a machine to browse the web, check email, and pay bills, most of that CPU's power is going to waste. That said, lower specs doesn't always mean less energy. Sometimes a component uses the same amount of power regardless, so add this to the list of details you research before making a purchase.
  • Go for integrated graphics over a dedicated card. High-end graphics cards from Nvidia and AMD require more power, even when idle. They also require more energy to cool.
  • Have as few moving parts as necessary. A spinning hard disk drive uses more power than a solid state drive. A computer with a fan needs more energy than a machine that's fanless.
  • Look for "low-power" computers or components. Some pre-built tiny PCs use comparable energy to a laptop, if not less. You may also see manufacturers or retailers market such products as "low-wattage."
  • Go portable. If you don't need a desktop, switch to a laptop, tablet, or the smallest form factor you can get away with. Since portable devices run off batteries, manufacturers design them to be more energy efficient. They're also not plugged into the wall most of the time anyway. But once you go mobile, you'll have to wrestle with a faster upgrade cycle and planned obsolescence.

Do Newer PCs Use Less Energy Than Older Ones?

Not necessarily.

If an older PC only sees light usage (e.g. by running a lightweight Linux distro), then it may consume less energy simply because it isn't doing much. With so many different parts to consider, there are too many variables to offer a blanket answer.

Some newer PCs are more efficient than older models, while some older PCs use less energy by virtue of doing less.

If you really want to determine the amount of electricity your desktop PC consumes, you will need to consider how much energy various PC components use. Then monitor this information over time so you can make an informed decision when it's time to replace your machine.