Wattvision API ready for developers!

Today we're proud to announce the very first release of our APIs for upload to and download from the wattvision servers.  By exposing APIs we hope that hardware and software developers will build solutions that help consumers access, collect, and understand their energy use data. This is our initial release, so you can expect that our APIs will change and evolve in the coming months.

Upload API

The upload API allows you to send raw energy use data to wattvision for storage and visualization.  You get access to all of the features of wattvision, like email alerts, participation in red house green house, embeddable widgets for your blog, your place in the rankings, data on wattvision mobile (visit wattvision.com from your iPhone or Android Phone), and everything else we're working on.

Download API (experimental)

The download API gives you access to your data on wattvision.  In this experimental version, we give you access to the last five minutes of data, and the most recent data point.  With this info, you can create your own display for wattvision, or plug wattvision data in to any solution you may already have, like your home automation system, for example.

But the most exciting feature of the download API is that it works without changing firewall settings on your router or setting up dynamic DNS.  Wattvision is the first energy use device that provides an API to download data from the cloud, and we hope this will enable some really cool scenarios. Happy coding!


  1. The APIs are subject to change.
  2. Let us know if you build anything cool, we might showcase it! Ping info@wattvision.com.
  3. Try to avoid building mission critical things on the download API. Like any website, wattvision might go down for maintenance -- please don't count on us for something critical, we're still in beta. :)
  4. If you use the download API, it would be great it you had "powered by wattvision" somewhere on the main page of your site. We're still figuring out the details there, but something to note.

Announcing "Red House Green House"

The idea here is simple.  If your home is using more power than the average of other homes on wattvision, your home gets a red roof. If your home is using less than the average, it's got a green roof. It's a quick way to see how you're doing relative to everyone else on wattvision.  Here are some images from the wattvision map:

If you set your home to be private -- it won't show up in the map or in the browse list, but you can still see if it has a red roof or green roof on your My House page.

Behind the scenes, wattvision compares your present energy use with the 'system-wide average' -- the average of all users on wattvision -- every few minutes.  So you can actively work to get your house to have a green roof in just a matter of minutes, ensuring yourself a place among those working to save the environment while saving some money.  Your comments are appreciated!

EarthHour Report

On Saturday, March 27, 2010, we asked the wattvisionaries (our beta users) in three timezones to participate in EarthHour.  We gathered quite a bit of data from the event, and we'd like to share some of it with you.  But if you're just curious as to who "won" -- the winner is Rob Patton of Florida, who got his home's energy use down to a mere 28 watts from about 6:30p to 10:30p! Congrats, Rob! We'll be sending you a wattvision t-shirt.

So did our users participate in EarthHour? Yes, they did.  Let's look at the data aggregated from 12 homes on wattvision in the Eastern timezone.

Let's first look at the average energy use per house on Friday night, the night before Earth Hour.  From the graph, you can see that in the period between 8:30 and 9:30, homes averaged an energy consumption rate of about 2,250 watts.  The blue line is an Excel-generated trendline (6th order polynomial).

The next graph has the same axes and trendline, but contains the data from the night of Earth Hour -- Saturday March 27th.  You can see the 'dip' around Earth Hour, reaching its minimum around 9:15.

How about the day after Earth Hour and the following Saturday (exactly 1 week after Earth Hour)?

Here's Sunday after Earth Hour:

And here is the following Saturday, exactly one week after Earth Hour:


Based on the data presented, we think we can safely conclude that our users actually participated in Earth Hour last Saturday.  Whoo hoo!

So how much did our users save?  A quick calculation is required. Assume the 12 homes on wattvision typically average about 2,500 watts of consumption between 8:30-9:30pm, and that during earth hour, on average, the usage went down by 700 watts per home.  This means our users saved 8.4kWh of electricity, or about 34.2 pounds of CO2 that would have otherwise been released into the atmosphere!  You can check our calculation here. And also check out the EPA's Greenhouse Gas Equivalencies calculator.

Thanks again to the wattvisionaries for participating, and congrats again to Rob!

Wattvision gets an in-home display with Chumby

Wattvision on the Chumby

Sure, wattvision looks great on your laptop or your web-enabled phone, but what about those times when you don't want to whip out your phone or open up your laptop?

Well, enterprising wattvision beta user Ryan Carrington cranked out a solution -- a version of wattvision that works on Chumby, a multi-purpose in-home display unit.  We worked closely with Ryan, gave him access to the download API, and we can't thank him enough for his help with this!  Shown above is the Chumby One running at the House in Pennington, NJ. Ryan got it working on his Chumby Classic.

If you have a Chumby and Wattvision, it's quick and easy to set up this particular widget. Just grab the ID and API Key from http://wattvision.com/house -- click "settings" and scroll to the bottom.  You're probably already familiar with Chumby widgets, so it should be quite straightforward to set up.  You can see details on the wattvision widget at the chumby widgets site.

If you have one and not the other, we're in touch with the Chumby Team to see if there are more seamless ways we can work together, but for now, the widget is ready to use.  Thanks again Ryan!

Lots of great feedback since our beta launch

We've been well-received by the blogosphere so far.  Here are some choice quotes and comments -- we'll probably keep updating this post as we get more feedback.  Thanks to everyone for your constructive comments and notes!

"No electrician, access to real-time home energy data via web or cell, and ability to share data through social networking: the top most desireable features I've heard from participants in previous studies (Intel, Department of Energy) on home energy usage are all there."  - Jay Hasbrouck

Coverage on:

Washington Post version of Techcrunch story

JetsonGreen "Wattvision could really help a homeowner out. Knowledge is power, and knowing how equipment uses energy may cause some users to make changes to save energy."

TreeHugger  "But an interesting pricing structure, super simple displays, and social networking tools for energy consumption data could help set Wattvision apart from the rest of the market." (Topsy trackbacks)




Wattvision Public Beta Launch!

It's here -- the wattvision public beta for digital meters!  If you have an electricity meter like the ones pictured below, you can get the wattvision beta hardware for just $149 (for a limited time, use $50 coupon code wvbetablog at checkout).

You may have never looked at your electricity meter before.  It's got all the information on your energy use. And it's probably outdoors.  If it looks like one of these, the wattvision sensor can connect to it and start uploading data to wattvision servers. (While you're investigating, take a picture with your phone and send it to meters@wattvision.com, and we'll tell you if our sensor is compatible.)

Digital meters like the ones pictured above have been found all over North America.  We currently have sensors running in Massachusetts, New Jersey, Florida, California, Ontario, and British Columbia.  (If your electricity meter doesn't look like this, send us a photo at meters@wattvision.com and we will notify you if our sensors are compatible.) Yes, more meter types are forthcoming.

The wattvision sensor hardware is self-installed and connects to your meter and your 802.11b wireless network, and uploads data directly to the wattvision servers. You'll have data updating live on the web or your iPhone.  Get your sensor now to see how much energy you're using, and how you compare to other wattvision users.  Check out wattvision mobile on your iPhone right now, and add it to your home screen. Just navigate to wattvision.com in Safari!

Today marks a big step in our exciting journey. We thank everyone that has given us help, support, and advice. We sincerely hope that we are making something people want (let us know if we're not!). Our twitter account and our blog have been dark for a while -- we imagine that we will have a lot more to say now, so stay tuned for updates. ;)

Understanding your electricity meter with Wolfram Alpha

Energy use is all the rage these days -- but few people know how to read their own electricity meters.  Here's how you can find out your live use, in watts, with a little help from Wolfram Alpha.

If you're like most people, you have an analog meter that looks something like the attached photo.  It features several clock-like dials, a bunch of numbers and codes, and a spinning ferraris disk that should be rotating now, if you're using any electricity at all in your house.

You'll need to find one key number on your meter. Let's call it the multiplier. It's usually labeled with Kh, Kp, or Ka, and is typically 6 or 7.2 on homes in the United States. For our example, we'll assume it's 7.2.

The multiplier is equal to the number of watt-hours of energy that pass through your meter per revolution of the spinning disk.  Without getting lost in energy units, take a close look at your meter's disk.  You'll notice it's got a mark on it (or many marks) that you can use to count revolutions.

With a stopwatch, time how long it takes for one revolution (rev) of your disk, in seconds.  Let's say it takes 15 seconds for your meter's disk to complete one rev.  Type the following into wolfram alpha:

[multiplier] watt-hours per [time for one rev.] seconds in watts
7.2 watt-hours per 15 seconds in watts >

Ta-da! You get an answer in watts -- 1,730 watts.  If your energy use remains constant for 1 hour -- you will have used 1.73 kilowatt hours.  A typically kilowatt-hour costs around $0.15 in the northeast, so you just spent nearly 30 cents on electricity.

If you try this out, post your results in the comments!  Now, as you can imagine, wattvision simplifies this procedure quite a bit.  More on that soon! ;)

Thanks! @ab90 @jeff @rafe @seth @dshen @davemcclure @damienmulley @davidadewumi

Demo days are over.  Many thanks to the following attendees who tweeted about wattvision!

@ab90 - view tweet - view blog post
@damienmulley view tweet
@davemcclure view tweet
@davidadewumi view tweet
@dshen view tweet
@jeff view tweet
@rafe view tweet view article
@seth view tweet

You can see more tweets about us on search.twitter.com -- and watch for our responses to the questions on twitter.com/wattvision. :)