Friday, March 19, 2010

power usage: first observations from PowerMeter

We've started getting data from the TED 5000 and Google PowerMeter. They display the same data, but in different ways. The TED 5000 web page gives more detailed info, but PowerMeter makes it easier to compare your current usage with past usage.

First, let's look at a fairly typical day's usage in PowerMeter:

In the wee hours of the morning, you can see a regular spike about every hour or so. That's the refrigerator coming on. Around 6:30AM you can see the radiant heat in the bathroom coming on, lights, the coffee maker, etc.

The other thing of note is the darker green band at the bottom. That's the "always on" power consumption I mentioned last time. It's only about 85 watts, but since it's always on, that adds up -- over 2kWH per day, which is more than 20% of the 9.7kWH per day we averaged last billing cycle. With our other source of info, the Kill-a-Watt, I've found about 25 of the 85 watts so far. Unfortunately nothing in that 25 is easy to get rid of, but I'll keep checking to find the other 60 and see what I can eliminate.

Now let's move to a less typical day -- laundry day:

Note that the scale has been stretched from 0-1.5kW up to 0-5kW. That's because running an electric dryer causes a huge increase in power consumption. You can see the dryer running for two loads, plus a little secondary run after each to get rid of the last bit of dampness. This is a big vote for line drying your clothes to save energy. It takes longer than just throwing everything in the dryer, but clearly can save a bunch of power consumption since the sun is free.

For more detail about power consumption, you can also view the TED 5000 web page for your device:

There's a live dashboard that shows your current power consumption, power used since midnight, etc. You can also view historical data. But the most useful is the graphing tab, which lets you see your energy consumption in near real-time, with more detail than the PowerMeter gadget shows. You can click on the graph to show the power consumption at any given time on the graph; that's how I determined the "always on" power was about 85 watts. The fourth tab allows you to set up load profiles when certain equipment comes on. My first trial with that wasn't very successful, but I'm going to try again to profile the refrigerator and some other appliances.

So we haven't saved any energy yet, but we've got a lot more data about how to go about doing that now. Some of it, like line drying clothes is even pretty easy to do (at least when the weather permits) -- no fancy gadgets required.

1 comment:

nelsong said...

Thanks for posting your experience with the Google PowerMeter. I am interested to see how this data can impact users.