Sunday, March 6, 2011

Smart Grid or DIY power usage monitoring?

When energy prices go up, it piques my interest in Smart Grid technology and energy consumption monitoring, etc. I think "Smart Grid" technology is ironic, because the devices collect power statistics to control consumption while consuming power themselves. Conversely, you can't manage what you can't measure, and your dryer, water heater, hair dryer, and HVAC use a lot more juice than some small electronics. Also, there are some nifty devices available to do this without interfacing with your provider's meter, and they provide more detailed information. Folks are saving hundreds by finding energy waste by proactively looking at usage data and accordingly unplugging things or changing usage habits, water heater and thermostat settings, etc.

In Texas (among other places), the utilities have been replacing meters on houses with ones that use a 900MHz mesh network protocol (IEEE 802.15.4). The providers can do remote connect/disconnect and automatically read the meter without tromping into your yard and upsetting your pets. In fact, they are collecting and storing smart meter usage data at 15 minute increments, which is sort of creepy in a 1984 kind of way. They know when you run your dryer or when your A/C kicks on and possibly the size of the compressor on your fridge and how often it cycles. If you want to know what they know, there are devices you can connect to your home router that can participate in this network, gather your power usage info and upload much more detailed data to web sites, like Microsoft Hohm or Google Powermeter. These web apps can show graphs of your power usage on your computer or smartphone. These may be unnecessary in Texas, because there is a Smart Meter Texas Portal which is a joint project by Oncor, CenterPoint, and AEP Texas under the direction of the Texas Public Utility Commission. It's publicly funded, probably by federal stimulus money, and available for free by signing up here using info from your power bill:

If you live in Oncor territory in North Texas, they use ZigBee Smart Energy Protocol 1.0. I found a variety of in-home displays (IHDs) to show your current power usage and hourly/weekly/monthly cost. There should be a way to get an in-home display for cheap or free, because in 2009 the Department of Energy allocated $3.4 billion in stimulus grants for smart grid projects, including the deployment of over a million IHDs. (Sidenote: It appears that Cisco is getting their money back for contributing $187,472.00 to the Obama Campaign and about $2 million a year for lobbying. See Cisco HEM for home energy monitoring and Cisco HEC for home energy control devices.)

Here's a ZigBee to IP/Ethernet bridge to connect to your home network. You can connect thermostats, meters for individual appliances (freezer, hot water heater, etc.), displays, and TV-connected controllers and other things once you have a ZigBee home area network (HAN).

I'm not sure that most of this Smart Grid stuff the utilities are doing is ready for prime time. ZigBee SEP 1.0 is being supplanted by a more capable and IPv6 compatible SEP 2.0 protocol, which is not backwards compatible. So, you have to buy devices compatible with (or upgradeable to) whatever version your meter is. Here's Oncor's take on that. Besides, if your house doesn't have a smart meter, or you don't know which protocol it's using: AMR-ERT(old), AMI/ZigBee 1.0(new), ZigBee 2.0(newest). That's necessary information to buy the right interface, you can capture the data yourself with some cool new products. I haven't found a gateway that is compatible with all of them, probably because they're so different.

Of course, there's more than one way to do that. There is a meter you can clamp around your breaker panel wires yourself and a WiFi gateway to push data to Microsoft-Hohm or Google Powermeter. Here's a comparison of Envi by Current Cost and Blueline products. The PowerHouse eMonitor works with Google Powermeter and monitors each circuit in your breaker panel, which lets you pinpoint what's sucking up the juice and costing you money.

Pricewise, the cheapest way to go is to just get a government subsidized IHD that works with your meter to see your electricity spend in real time. The next cheapest solution, which gives you historical usage info, is to get the smart meter interface (iTronERT or ZigBee to IP/Ethernet gateway) for about $200. No smart meter? Not smart meter smart? The other solutions involve metering it yourself at the breaker panel and sending the data to the cloud via WiFi. These kits start at around $300 for the meter and the network interface. You can also get an IHD or access it with a browser or an iPhone or Android App. I suppose it'll pay for itself over time if you can find when, and therefore what, is wasting power.

I'm guessing these things will be mainstream in a year or two when the industry standardizes on the best protocols and the price comes down on the hardware.