The 2019 Wikimedia Foundation Sustainability Assessment states that server electricity usage accounts for 54.6% of Wikimedia's carbon footprint. It would be nice to be able to break that figure down further, for example, by prometheus cluster. This would improve our ability to identify potential efficiency projects.
For Dell servers there is dellhw_exporter, although this requires OMSA to be installed. This is no easy task since there are no recent Debian packages available. However, the same information is apparently available with IPMI:
$ ipmitool -c -I lanplus -H mw1333.mgmt.eqiad.wmnet -U root -E delloem powermonitor powerconsumptionhistory Power Consumption History Statistic Last Minute Last Hour Last Day Last Week Average Power Consumption 155 W 155 W 160 W 165 W Max Power Consumption 199 W 199 W 220 W 244 W Min Power Consumption 117 W 117 W 105 W 97 W Max Power Time Last Minute : Thu Nov 7 02:05:33 2019 Last Hour : Thu Nov 7 02:05:33 2019 Last Day : Wed Nov 6 12:27:57 2019 Last Week : Tue Nov 5 22:25:05 2019 Min Power Time Last Minute : Thu Nov 7 01:36:15 2019 Last Hour : Thu Nov 7 01:36:15 2019 Last Day : Wed Nov 6 19:55:55 2019 Last Week : Sun Nov 3 02:05:35 2019
The idea would be to write a Prometheus plugin which runs this command and parses the response to extract the one minute average power consumption. Resolution is only 1W, but the same resolution is shown in the iDRAC web UI so it is probably the best that is physically available.