How much energy is Sagebrush consuming? We did an energy audit of one developer workstation, to get a general idea of how much electricity is used and look for ways to reduce energy use and carbon footprint.
The P4400 Kill-A-Watt meter is inexpensive and easy to use for measuring power (and volts, current, total energy, etc). Plugging the unit directly into a wall socket didn’t work well for us, since the display on this model is not illuminated and not particularly easy to read at standard wall socket height under a desk, but using the meter with a short extension cord worked fine. We might prefer higher resolution, so we can measure fractions of watts, but this is fine for the price.
While measuring we found several old unused wall-wart voltage adapters still plugged in wasting electricity, now discarded.
This workstation uses a laptop running Vista as main computer. The computer runs in dual-monitor mode with an external monitor and laptop screen. We use another laptop running XP, for testing and executing some programs not available on Vista, currently rarely used.
| DEVICE | Device Model | Active(W) | Standby(W) |
| laptop | Acer Aspire 5570 |
35 |
1 |
| 17″ LCD Monitor | HP L1815 |
35 |
1 |
| laptop 2 (rarely active, running WinXP) | Acer TMate 2300 |
40 |
1 |
| cable modem | D-Link DCM-202 |
3 | |
| wireless router | D-Link DI-713P |
8 | |
| VOIP phone adapter | Linksys PAP2 |
2 | |
| USB hub with devices (keyboard,mouse,tuner,scanner) | Belkin F5U237v1 |
5 |
4 |
| Laser printer | HP LaserJet 4L |
300 |
3 |
| cordless phone base | Uniden TRU8865 |
3 |
2 |
| miscellaneous wall warts (cell, blue-tooth, etc) |
4 |
Typical total power used is 105 watts when the first computer is active. The meter is able to measure total energy used directly. In a typical 24 hour period, we measured 1.52 kilowatt-hours. Somehow the computer and external monitor are staying active for longer than we expect, so we will investigate further.
What is annual electricity cost and resulting CO2 emission per workstation? We will consider in a later post.