If you’re like me, you will go out of your way to minimize your utility bills. While you can take steps to lower water usage with low flow toilets and fixtures, nothing compares to the granularity possible as with per-device electricity monitoring.
This all came to light when I had left the house for a week during the holidays. Expecting to see near zero usage, I checked my smart meter through my electric utility provider’s website and was shocked to see that, while I was several thousands miles away, my home was consuming just over 4kWh a day in electricity. I decided right then and there that I needed to be much more conscious of the devices left running while I was away and of those that needed to be on 24/7, I wanted to know just how much they were costing.
My home is powered by an INSTEON network of home automation devices, controlled by a Mac mini running Perceptive Automation’s Indigo. This tutorial will show you how to monitor your energy usage on a per-device basis for as many devices as you care to monitor. This tutorial assumes you already have an Indigo installation up and running.
Step 1: Step 1: Energy Variables
Add your iMeter Solo(s) to Indigo and give them names that will help you identify their monitored load. You don’t need to worry too much about the polling frequency, we will be handling that through scheduled actions.
Open the Variables List from the Window menu and click the plus sign in the bottom left of the window to create a new variable group. Name the variable group something specific to an individual device, for instance: Energy Monitoring (Furnace).
Next, we will create a variable for this device at each hour of the day, 24 variables in all. Click the New… button in the upper left corner of the Variable List window. As this variable set will monitor the hourly tally of your appliance, give the variable a name like “energyFurnace0100” where 0100 is the hour of the day. To prevent sorting issues, I suggest using 24 hour time (0100 through 2400).
When your variable list is complete, it’s time to move on to the schedules that will log the current consumption.
Step 2: Step 2: Logging Schedules
On their own, your variables won’t actually do much. We need to create a schedule that will log the current power consumption of your iMeter using each variable.
Select Schedules from the left sidebar in Indigo and click the New... button in the upper left corner. Give your schedule a name, something like “Energy - Furnace - 0100.”
Set the time to match that of your schedule, in this case, 1:00AM. Leave the rest of the settings on the Schedule tab as they are and skip the Condition tab.
Under the Actions tab, select “Insert Device State into Variable” from the Variablessubmenu in the Type menu. Based on your version of Indigo, this command may be under a different submenu.
In the resulting Device menu, select the iMeter for this device, in this case, the Furnace iMeter.
Click the Edit Action Settings button. In the window that appears, select “curEnergyLevel” from the Insert State menu and select the correct corresponding variable from the Into Variable menu, in this case “energyFurnace0100.”
As of now, at 1:00AM, the current power draw detected by your “furnace” iMeter will be stored in the 0100 variable.
Take a few minutes and duplicate the schedule for each hour of the day (or half hours, etc. if you want increased granularity - although I’ve found hourly works very well for pinpointing power consumption spikes).
Step 3: Wrap Up
There are a few things to consider about this system.
1. As built, you can only see power consumption for the past 24 hours.
2. You might end up with a very large number of variables if you have multiple iMeters you wish to track.
Conceivably, you would use a few iMeters moved around the house to identify appliances and electronics that consume unexpectedly high amounts of power. After you’ve identified when they use the power, you can make decisions on what to do to resolve the issue. Sometimes it can indicate normal usage, other times it might help to identify a failing appliance.
At the very least, it is eye opening. I was shocked to find that the air handler for my furnace used 587W when on - and that’s completely indecent from any power consumed by the compressor when the AC is on.
If you want more control or just like jumping off the deep end, another Indigo user, nsheldon, has created a scripting addition to Indigo to track energy consumption of more than just iMeter solo devices. Give it a look here.