{"id":11117,"date":"2014-10-05T23:10:39","date_gmt":"2014-10-06T03:10:39","guid":{"rendered":"http:\/\/scruss.com\/blog\/?p=11117"},"modified":"2014-10-05T23:10:39","modified_gmt":"2014-10-06T03:10:39","slug":"log-your-electricity-consumption-with-powermon433","status":"publish","type":"post","link":"https:\/\/scruss.com\/blog\/2014\/10\/05\/log-your-electricity-consumption-with-powermon433\/","title":{"rendered":"Log your electricity consumption with Powermon433"},"content":{"rendered":"

NB:<\/em><\/strong> this is in the\u00c2\u00a0 early stages of development, but does work. It’s by no means a plug-and-play solution. You’re going to have to do some coding, and perhaps some soldering. Undaunted? Read on \u00e2\u20ac\u00a6<\/em><\/p>\n

I really like the\u00c2\u00a0Blue Line Innovations PowerCost Monitor\u00e2\u201e\u00a2<\/a> (aka the Black & Decker Power Monitor EM100B<\/a>). I bought one long before the OPA started to give them away free to Ontario households as part of their peaksaver PLUS<\/a> program. It’s a little device that clamps to your hydro meter and sends instantaneous power readings to a display.<\/p>\n

\"PowerMonitor-displays\"<\/a>
Power Monitor displays \u00e2\u20ac\u201d Black & Decker on the left, Blueline on the right<\/figcaption><\/figure>\n

Wouldn’t it be so much better if you could log and analyze these data? So a day’s power consumption might graph to something like this:<\/p>\n

\"PowerMonitor-20140929\"<\/a>Yup, this is my real electricity consumption, as logged from the PowerCost Monitor. You can see the fridge cycling on and off, and I think the big mid-day spike was either the AC or the dryer; someone was home on that Monday. The rather blocky green line is Toronto Hydro’s hourly smart meter data. It really hasn’t got the resolution to show really detailed power use.<\/p>\n

That spike at 06:30; what’s that? Let’s take a look:<\/p>\n

\"PowerMonitor-20140929-kettle\"<\/a>That’s me boiling the kettle. You can see that the time resolution is better than a minute, and the power is to the watt. Mmm, coffee \u00e2\u20ac\u00a6<\/p>\n

All of this is recorded using a simple Arduino-based solution, originally cooked up by Bryan Mayland<\/a>. I’ve forked his code and added some instructions: scruss\/Powermon433<\/a>. Here’s the rig I’ve been using to log data over a USB serial link:<\/p>\n

\"Arduino<\/a>
Arduino FIO compatible + RFM69W board + FTDI serial<\/figcaption><\/figure>\n

That’s a particularly ugly rig, due to the limitations of the 3.3 V receiver board I was using. There are other options that work with more normal Arduino boards up on github.<\/p>\n

Here’s a sample of the data I’m logging, including the kettle incident:<\/p>\n\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Datetime<\/span><\/b><\/td>\nElapsed_s<\/span><\/b><\/td>\nEnergy_Wh<\/span><\/b><\/td>\nPower_W<\/span><\/b><\/td>\nTemp_C<\/span><\/b><\/td>\n<\/tr>\n
2014-09-29T06:27:44<\/span><\/td>\n23241.7<\/span><\/td>\n25876<\/span><\/td>\n289<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:28:16<\/span><\/td>\n23273.6<\/span><\/td>\n25876<\/span><\/td>\n290<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:28:48<\/span><\/td>\n23305.5<\/span><\/td>\n25876<\/span><\/td>\n291<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:29:20<\/span><\/td>\n23337.4<\/span><\/td>\n25892<\/span><\/td>\n294<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:29:52<\/span><\/td>\n23369.2<\/span><\/td>\n25892<\/span><\/td>\n286<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:30:24<\/span><\/td>\n23401.1<\/span><\/td>\n25892<\/span><\/td>\n277<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:30:56<\/span><\/td>\n23433.0<\/span><\/td>\n25892<\/span><\/td>\n357<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:31:28<\/span><\/td>\n23464.9<\/span><\/td>\n25892<\/span><\/td>\n1844<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:32:00<\/span><\/td>\n23496.8<\/span><\/td>\n25892<\/span><\/td>\n1836<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:32:31<\/span><\/td>\n23528.5<\/span><\/td>\n25952<\/span><\/td>\n1829<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:33:03<\/span><\/td>\n23560.2<\/span><\/td>\n25952<\/span><\/td>\n1818<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:33:35<\/span><\/td>\n23592.1<\/span><\/td>\n25952<\/span><\/td>\n1836<\/span><\/td>\n15<\/span><\/span><\/td>\n<\/tr>\n
2014-09-29T06:34:07<\/span><\/td>\n23624.0<\/span><\/td>\n25952<\/span><\/td>\n1836<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:34:39<\/span><\/td>\n23655.8<\/span><\/td>\n25952<\/span><\/td>\n1836<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:35:11<\/span><\/td>\n23687.7<\/span><\/td>\n25952<\/span><\/td>\n1848<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:35:43<\/span><\/td>\n23719.6<\/span><\/td>\n26048<\/span><\/td>\n1832<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:36:15<\/span><\/td>\n23751.5<\/span><\/td>\n26048<\/span><\/td>\n2000<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:36:46<\/span><\/td>\n23783.4<\/span><\/td>\n26048<\/span><\/td>\n2000<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:37:18<\/span><\/td>\n23815.2<\/span><\/td>\n26048<\/span><\/td>\n2000<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n
2014-09-29T06:37:50<\/span><\/td>\n23846.9<\/span><\/td>\n26048<\/span><\/td>\n368<\/span><\/td>\n15<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

You’ll see that I’m recording:<\/p>\n

    \n
  • a system timestamp<\/li>\n
  • the elapsed logging time, from the Arduino’s clock<\/li>\n
  • instantaneous meter readings in watt-hours. Note that not every row has an update<\/li>\n
  • the average power since the last record. The product of this and the time between records adds up to the energy consumption<\/li>\n
  • the outside temperature in \u00c2\u00b0C. This is not very accurate (in full sun it over-reads vastly) but better than nothing.<\/li>\n<\/ul>\n

    Compare that to the smart meter data:<\/p>\n\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n\n\n\n\n\n
    DateTime<\/span><\/b><\/td>\nHour<\/span><\/b><\/td>\nKwhUsage<\/span><\/b><\/td>\nCost<\/span><\/b><\/td>\nRate<\/span><\/b><\/td>\n<\/tr>\n
    2014-09-29 05:00:00<\/span><\/td>\n5<\/span><\/td>\n0.29<\/span><\/td>\n$0.02<\/span><\/td>\n$0.075<\/span><\/td>\n<\/tr>\n
    2014-09-29 06:00:00<\/span><\/td>\n6<\/span><\/td>\n0.31<\/span><\/td>\n$0.02<\/span><\/td>\n$0.075<\/span><\/td>\n<\/tr>\n
    2014-09-29 07:00:00<\/span><\/td>\n7<\/span><\/td>\n0.59<\/span><\/td>\n$0.04<\/span><\/td>\n$0.075<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Not much data there, is there? Certainly not enough resolution to tell if a kettle has been running.<\/p>\n

    Even though this interface is homebrew and cheap, it is accurate. Here’s how four days of continuous readings stack up against Toronto Hydro’s meter:<\/p>\n\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n<\/colgroup>\n\n\n\n\n\n\n\n
    \u00c2\u00a0<\/span><\/td>\nPower Monitor<\/span><\/b><\/td>\nndToronto Hydro Smart Meter<\/span><\/b><\/td>\n<\/tr>\n
    Day<\/span><\/b><\/td>\nFirst Reading \/ Wh<\/span><\/b><\/td>\nLast Reading \/ Wh<\/span><\/b><\/td>\nTotal Consumption \/ kWh<\/span><\/b><\/td>\nNo of readings<\/span><\/b><\/td>\nDaily Total \/ kWh<\/span><\/b><\/td>\nNo of readings<\/span><\/b><\/td>\n<\/tr>\n
    2014-09-29<\/span><\/td>\n23896<\/span><\/td>\n43668<\/span><\/td>\n19.772<\/span><\/td>\n2711<\/span><\/td>\n19.77<\/span><\/td>\n24<\/span><\/td>\n<\/tr>\n
    2014-09-30<\/span><\/td>\n43668<\/span><\/td>\n52500<\/span><\/td>\n8.832<\/span><\/td>\n2710<\/span><\/td>\n8.82<\/span><\/td>\n24<\/span><\/td>\n<\/tr>\n
    2014-10-01<\/span><\/td>\n52500<\/span><\/td>\n68004<\/span><\/td>\n15.504<\/span><\/td>\n2711<\/span><\/td>\n15.51<\/span><\/td>\n24<\/span><\/td>\n<\/tr>\n
    2014-10-02<\/span><\/td>\n68004<\/span><\/td>\n81996<\/span><\/td>\n13.992<\/span><\/td>\n2712<\/span><\/td>\n13.99<\/span><\/td>\n24<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    The difference looks to me like aliasing; THES’s reporting is much more granular.<\/p>\n

    I’m going to develop this further to turn it into an easy (or at least, easier) to use logging platform. It’s taken us a few years to get here, but there’s nothing quite like a project finally working!<\/p>\n","protected":false},"excerpt":{"rendered":"

    NB: this is in the\u00c2\u00a0 early stages of development, but does work. It’s by no means a plug-and-play solution. You’re going to have to do some coding, and perhaps some soldering. Undaunted? Read on \u00e2\u20ac\u00a6 I really like the\u00c2\u00a0Blue Line Innovations PowerCost Monitor\u00e2\u201e\u00a2 (aka the Black & Decker Power Monitor EM100B). I bought one long […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[2837],"tags":[2207,2838,2750,2839,1566,2795,912,2835],"class_list":["post-11117","post","type-post","status-publish","format-standard","hentry","category-powermon","tag-arduino","tag-black_and_decker","tag-blueline","tag-consumption","tag-electricity","tag-github","tag-hydro","tag-powercost"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pQNZZ-2Tj","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/posts\/11117","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/comments?post=11117"}],"version-history":[{"count":6,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/posts\/11117\/revisions"}],"predecessor-version":[{"id":11127,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/posts\/11117\/revisions\/11127"}],"wp:attachment":[{"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/media?parent=11117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/categories?post=11117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scruss.com\/blog\/wp-json\/wp\/v2\/tags?post=11117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}