3D printers are accused of using a lot of electricity and are thus harmful to the environment.
High end FDM printers use around 50 Watts of power while similar lower cost printers consume as much 125 Watts of power after the printer has reached its target temperature. Resin printers consume about 60 Watts of power while the UV light is running and 20 Watts between exposures.
The Experimental Setup
If you have been around the 3D printing community, you might have seen this article from 3D Print Headquarters about how much electricity a 3D printer uses. Unfortunately, that article is no longer available but it is saved at Archive.org.
The experiment that was conducted was on a MakerBot Replicator 2, a much higher end 3D printer. Since this resource is not longer available, I have decided to replicate the experiment with a bit more precision.
My printer is an Ender 3 V2. This is a popular hobbyist printer.
The print that I made was the ever popular Benchy, available on Thingiverse.
|Hot End Temperature||200º C|
|Bed Temperature||75º C|
|Layer Height||0.1 mm|
|Wall Thickness||0.8 mm|
|Print Speed||60 mm/sec|
Before I get into the results, I want to explain a couple of terms.
Power is the rate at which energy is transferred. It is like your speed when you are driving. Electrical power is measured in Watts.
Energy is the measure of total work done. It is the sum of power over time and is equivalent to the total distance driven. Electrical energy is measured in Watt-hours.
The print took 2 hours and 57 minutes from the initial warmup to completed print. The total energy over the print was 381 Watt-hours.
What is surprising is that I found that the normal power consumption was about 2.5 times that reported previously. Either the Ender 3 uses more power than other printers or there was an issue with the power strip I was using to collect the data.
I verified the data I was getting using this Power Monitor. My original plan was to use this monitor to get the usage data but it would have required me to manually monitor power consumption.
Now that I have 2 independent power monitors giving me the same power consumption data, I am confident that I am getting the correct data.
There was a weird drop in power for a few seconds around the 2 minute mark. The power reading in the data was about 7 Watts, which is the power consumption when the machine is on but not heating up. This occurred when the bed was heating up and had reached 65º C. There was no noticeable issue at the time and had no effect on the print.
We can clearly see on this chart the spike in power consumed when the hotbed is heating up. One the bed reached its temperature, and the hotend began to head up, power consumption was still high but not as high. This means the biggest driver of power consumption is the heated build plate.
Interestingly enough, while the build plate was heating up, the hotend also started to warm slightly. Not a lot, but enough to show up on the graphs. Since the hotend was sitting just above the build plate, the heat from the plate was enough to slightly warm the hotend.
My setup used 200º C hotend and 75º C heated bed. Did the higher temperatures force the printer to use much higher power to maintain them?
Lowered Temperature Results
To determine if the higher temperatures I used were the cause of the increased energy consumption, I lowered the hotend to 185º C and the hotbed to 60º C.
Despite using the same GCODE file, changing just the values for the temperature, the second print took 2 hours and 42 minutes. This print was almost 15 minutes faster. The first print reached the goal temperature in about 5 minutes so it cannot be that the time saved came from being able to reach the print temperature faster.
The total energy for the second print was 269 Watt-hours.
We can clearly see that the power consumption dropped to around 100 Watts. This is still higher than reported previously but much closer.
Again, let’s look at the first hour of the print.
This second print heated up faster but it also started at a higher temperature. This explains why the power consumption was lower at the start and total energy was lower.
The difference in power once the prints reached their target temperature is dramatic. We get a decrease in power of around 25 Watts.
What caused such a significant difference in power?
Looking at the Replicator 2 that was used to get the original 50 Watt power measurement, there are some striking differences compared to my Ender 3.
While the Replicator does not have a full enclosure, the back is solid and there is little opportunity for air flow around the build plate.
Most of the power being consumed is used to maintain the hotend and build plate temperature. With less airflow underneath, the Replicator may be better able to maintain its build plate temperature and consume less power.
One way to mimic this is to use an enclosure. I purchased an 3D printer enclosure from Amazon so that I could move my 3D printer into the garage.
Another difference between the Ender 3 V2 and the Replicator 2 is the build plate size. The Replicator has a build plate that is 285mm x 153mm rectangular. My Ender 3 build plate is 220mm x 220mm square.
Thus the Replicator 2 has a rectangular build plate with a surface area of 43,605 mm2 and the Ender 3 has a square build plate surface area of 48,400 mm2, almost 11% larger.
While I would not be surprised if the energy required to maintain the temperature of a build increased in a non-linear fashion (meaning double the area more than doubles the required energy for the same temp), I find it hard to believe that an increase of 11% would double energy required.
Again, I printed the same benchy, this time using the enclosure. The print took 2 hours and 43 minute and consumed 304 Watt-hours of energy.
Looking at the chart, I am a bit disappointed with the results.
Based on the power consumption chart and the energy consumes, can you guess which benchy I used? You might guess the 200º C. It looks like it started around 125 Watts initially and dropped closer to 110 Watt. As the air in the enclosure warmed up, less power was needed.
Unfortunately, I used the 185º C print.
There is some other factor that is affecting the power consumption that is not clear from the data. These prints were done during different times of the day.
While I made sure the build plate was cooled to room temperature before starting, I did not check the temperature of the electrical components, which may have been warm from my attempt to re-level the bed before the print. The bed got misaligned after putting it in the enclosure.
What ever factor may have resulted in the slightly higher consumption in the enclosure, I do not think it can account for the difference in power consumption with the Replicator 2.
The most likely culprit is the cheaper parts used in lower cost 3D printers. To save on costs and get a printer that is priced for a wider market, electrical parts that are less efficient may have been used.
This only covers FDM printers, but what about resin printers?
Resin Printer Power Consumption
What we have not seen is any measure of how much power a resin printer uses. Resin prints do not heat up, so we would not expect them to consume as much power as an FDM printer.
I printed the benchy on my Anycubic Photon Mono X.
The power consumption of the resin printer fluctuated between 20 Watts and 58 Watts. The upper limit is when the UV light is emitting and the lower is when the build plate is moving up and down.
The first few layers are exposed to the UV light longer than later layers. We can see that in the chart where power consumption stays higher for an extended period of time.
It is interesting to see that power peaks initially and then slowly drops a couple of Watts over a couple minutes. This printer is in my garage and most likely started warm. Once the fan started running, the printer cooled to a steady state.
My results were surprising given what has been reported by 3D Print Headquarters. While previous power consumption was significantly lower, they were also using a much higher end printer.
This experiment provides an essential contribution to the 3D printing community. While we have for years been claiming that 3D printers are only consuming 50 Watts of power, this is certainly not the case for all printers.
Additionally, I have contributed to the discussion data involving resin printers. While these printers may not be as popular as FDM, hobbyists may want to consider using resin if they are concerned about their power usage.