A Common BTO “Gotcha”: “My electricity bill went way up”
When buying a PC through a build-to-order (BTO) provider—especially a desktop—“my electricity bill went way up” is a very common experience.
If the PC is rarely used, or used for only about an hour a day, the impact may be small. But the more hours a PC runs, the more it can affect the monthly electricity bill.
Situations where electricity costs jump
Switching from a laptop to a desktop
With remote work becoming more common, more people are deciding that “if the work is at a home desk, a desktop is fine,” which has increased upgrades from laptops to desktop PCs.
What often surprises people who move from a laptop to a desktop is the next month’s electric bill—along with the improved responsiveness and comfort of the PC itself.
In general, laptops typically draw around 50–120 watts while in use, while desktop PCs are commonly around 120–300 watts. Some high-performance PCs can even exceed 700W under heavy load.
For example, Apple’s newer Mac Pro models became a hot topic for their performance, and on the highest-end configuration:
- Power consumption at maximum CPU load = 902W
- Power consumption in standby = 302W
Mac Pro power consumption and thermal output (BTU/h)
That’s more than 10× a typical laptop—roughly in the same ballpark as running a home heater in winter.
Very few PCs are as power-hungry as a high-end Mac Pro, but with higher-spec desktop PCs, electricity costs that were easy to ignore on a laptop can become noticeable—especially the more hours the PC is used.
Upgrading to higher-end CPU and GPU parts
With BTO PCs, parts like the CPU and memory can be customized, which makes it easy to get excited and want to “go with something faster!” However, upgrading the GPU and CPU—especially to higher-end models—often increases power draw as well, making it more likely to end up with a power-hungry PC.
For example, many desktop CPUs are around 65W TDP, but a 64-core Ryzen Threadripper can be 280W (an increase of more than 200W).
The same goes for GPUs. The GeForce GTX 1660 Ti, commonly used in entry-level gaming PCs, has an 80W TDP, while the previous generation’s flagship GeForce GTX 1080 has a 180W TDP—an extra 100W.
If both upgrades were done, total power draw could increase by roughly 320W. Assuming electricity costs 25 yen per 1 kWh (about $0.23), that would mean:
- Electricity cost increases by up to about $0.07 per hour
- Up to about $2.25 for 1 hour a day (30 hours/month)
- Up to about $18 for 8 hours a day (240 hours/month)
If switching from a laptop, the display’s electricity use would also be added, so the monthly bill could increase by more than 2,000 yen (about $19). At about $19 per month, that’s about $225 in one year, or about $450 in two years—enough to make a noticeable difference in the total cost of owning the PC.
This is an extreme example because it assumes “maximum load,” but it should make it clear how much electricity costs can rise.
That covers electricity costs for desktop BTO PCs.
Even if the cost per hour seems minor, over one or two years it can add up to a meaningful amount. When building a BTO PC for long work hours (not just as a hobby PC), it’s worth calculating electricity costs up front.
This matters even more for offices that deploy 10 or 20 machines, where “long hours + multiple PCs” can make electricity costs add up quickly.
Of course, if there are benefits that justify it (like improved productivity), that’s a different story.
