Last night at Green Drinks Boston, the buzz was about WattsOn, which is DIY Kyoto's gadget for monitoring home energy use.  I've heard a bit about this sleek little gadget before, although I haven't investigated.  I just took a gander at the website, and I'm mighty impressed!

WattsOn is a gadget that displays your current energy usage, using a sensor and transmitter which hook in to your electric meter.  The device also comes with software which allows you to monitor your usage over time, and to plug into a community of other WattsOn users.  Although I haven't tried out the device (it's apparently available in the UK, but not in the US), it appears to be designed exceptionally well - it could be a nice conversation-starter on a coffee table - and the software seems to handle most of the typical reports you'd expect.

As far as I can tell, the community tools attached to WattsOn are fairly basic - they allow you to see cumulative energy and monetary savings for the community as a whole, but that's about it.  There are plenty of other things that a community of people trying to reduce their energy usage can do - for example, review and recommend energy-efficient appliances, swap tips on the best ways to implement energy-saving practices, and so on.  Additionally, I can imagine a number of other ways to make the historical usage data available to users - e.g., over email, text message, and so forth.  Good data analysis might also reveal patterns that could help home energy users find additional savings above those offered by the typical measures, like replacing incandescent light bulbs with compact fluorescents.

While WattsOn is definitely a more comprehensive reporter than Tweet-A-Watt, it would be nice to get a breakdown of energy usage by room or appliance.  Depending on how it's implemented, Tweet-A-Watt is capable of creating that kind of breakdown, while WattsOn only displays aggregated usage.  On the other hand, WattsOn also takes 288 meter readings a day, so it's usually possible to reasonably approximate the reason for various spikes.  For example, if you turn on the clothes dryer around 6 pm, and see a big spike in the usage data starting at 6 and lasting for about 45 minutes, it's probably a good sign that the dryer was the cause of that spike.

WattsOn is an excellent tool in the energy efficiency arsenal.  While it's not yet available in the US, I hope it jumps across the pond soon!

Tweet-A-Watt is an elegant solution to the problem of tracking electricity.  While the smart grid gathers steam, it's still a long-term project, and many electricity consumers won't see results for several years.  Tweet-A-Watt addresses that problem in the short term.  By combining the Kill-a-Watt power meter, the XBee wireless board, and the Twitter API, Tweet-A-Watt gives consumers a device into which they can plug their appliances, and tweets their energy usage to Twitter.

The basic Tweet-A-Watt system could be improved by making the data available in a semantically meaningful way, i.e. via some sort of structured database for electricity usage which is API-accessible.  With that kind of data infrastructure in place, it would be possible to develop interesting tools that allow consumers to see historical trends in their electric usage; break down usage by outlet and/or appliances; and get alerts whenever their usage exceeds a certain limit.

Fortunately, the Tweet-A-Watt system is very accessible.  Start-up Tweet-A-Watt hardware packs cost $90, and Wattcher, the Tweet-A-Watt software, is open source.  An interested hobbyist could be up and running with Tweet-A-Watt in a weekend, without much trouble.

For wider distribution, it will probably be necessary to make Tweet-A-Watt a bit easier to build, and a bit cheaper - perhaps through a partnership with Kill-a-Watt, or by using a cheaper meter.  There's also a need for software that's a bit easier to use, perhaps using a software-as-a-service (SAAS) business model.  Such a service would allow users to register their Tweet-A-Watt systems, describe the kinds of appliances plugged in to each Tweet-A-Watt, view charts and graphs of their usage, and then receive alerts whenever usage jumps beyond some absolute or relative limit.  The software could even integrate with users' Facebook accounts, to let their friends know when they saved electricity thanks to Tweet-A-Watt.

While I think a SAAS model would be the easiest way to create a sustainable, accessible data store of electricity usage, the software could also be distributed as an open source web application, which motivated users could install on their own private web servers.  Neither the code nor the database structure for this kind of software is likely to be very complex, and probably won't require very sophisticated maintenance.

I'm always eager to see low-cost, accessible solutions like Tweet-A-Watt emerge, and I'm even more excited about the prospect of derivative services that make those solutions easy-to-use.  Making energy efficiency tools readily available is an important step in reducing our overall energy usage.