Tag Archives: green stuff

Current Cost – watt hours and pachube

This is an email i sent to JT  so I apologise if it doesn’t make sense to y’all. Please ask questions if you don’t get me!

So we have this ‘Current Cost’ meter thing (free from Southern Electric) at the house. It’s a small wireless electricity meter. Well it’s more of a monitor or display actually but you get me….[insert pic].

Long story short, I’d noticed the RJ45 on the bottom and it’d got me wondering. A few google searches later and whammo i’d found what I needed. A bit of hardware, a bit of software (links on manyfacturers website!) and whammo….

I wired up the current cost (enegry meter) at the house to my laptop and it’s uploading to this Pachube (bless you) website:
http://www.pachube.com/feeds/2196

The graph is a bit useless atm (no history or dates on it 🙁 ) but the program here:
http://apps.pachube.com/google_viz/
Could probs snazz it up a bit.
There seems to be a binary pattern from some device that is turning on and off at regular intervals and using ~100w… i wonder if it’s the compressor on the fridge/freezer as it goes on thru the night lol.

Graph of peak watts and temperature from current cost and excel

Graph of peak watts and temperature from current cost and excel

The long jittery spikes are the washing machine/dishwasher/tumble dryer (the last being the biggest draw lol).

One guy is even trying to record signatures for each appliance and then work out from the data which appliance is causing the spikes.
http://chrishodgins.tumblr.com/post/33810511/via-chart-apis-google-com-so-its-the-bank
The idea behind this is if you can work that out, you can make a pie chart of the biggest consumers…

I have more results than are uploaded; i created a funky excel file which Should update from the mdb created from one of the apps i’m using but atm i think the file is locked or summat :(. Made a pretty graph to! Also predicting the future temperature based on a polynominal curve or something lol.

All gd fun. Now i jus want one of these tiny minuture computers:
http://www.fit-pc.co.uk/fit-pc-slim.html
or this awesome plug pc:
http://www.pcpro.co.uk/news/258238/plug-sized-pcs-arrive-in-uk.html (sweet) (Ubuntu on a plug [ via Youtube])
to record/upload the results, although it would make more sense to use the ipcop or home server since they are always on and the current cost device is wireless. (unfortunately our model does not have internal data logging 🙁 ). Don’t know how to work out kwh from current usage of watts every 3 seconds… i might be able to put something from averages tho. Any suggestions  anyone? I might just be being dumb lol.

Now all we need is the x10 plug thru devices to monitor electricty usage (by appliance) and bobs your uncle – we know exactly where the electricity is going.

IMO  (as a soon to be Building services engineer in training) this technology should be wired into all new houses in the actuall plug sockets. Want to know which of your kids (or indeed partner) is using the most electricity? 😉

The trickle usage these measuring devices could be designed to run on could easily be offset by a small(ish) solar pv installation too! (i’m talking around 10-30wh/day here 😉 ).

Oh and here’s how to connect the current cost to pachube:
http://community.pachube.com/?q=node/100

On the upside i’ve also unplugged the fancy pants MPPT  solar charge controller and hooked the install back up to the basic on/off controller, and now it’s definetly shifting amps! I was a bit worried that in full sun 53watts of panels was ONLY putting through 0.3-0.1a @11.7 (i know, discharged). Hmm gonna have to find out whats wrong with fancy pants, he wasn’t cheap! :'(