Tag: hydro

Log your electricity consumption with Powermon433

NB: this is in the  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 …

I really like the Blue Line Innovations PowerCost Monitorâ„¢ (aka the Black & Decker Power Monitor EM100B). I bought one long before the OPA started to give them away free to Ontario households as part of their peaksaver PLUS program. It’s a little device that clamps to your hydro meter and sends instantaneous power readings to a display.

PowerMonitor-displays
Power Monitor displays — Black & Decker on the left, Blueline on the right

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:

PowerMonitor-20140929Yup, 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.

That spike at 06:30; what’s that? Let’s take a look:

PowerMonitor-20140929-kettleThat’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 …

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

Arduino FIO compatible + RFM69W board + FTDI serial
Arduino FIO compatible + RFM69W board + FTDI serial

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.

Here’s a sample of the data I’m logging, including the kettle incident:

Datetime Elapsed_s Energy_Wh Power_W Temp_C
2014-09-29T06:27:44 23241.7 25876 289 15
2014-09-29T06:28:16 23273.6 25876 290 15
2014-09-29T06:28:48 23305.5 25876 291 15
2014-09-29T06:29:20 23337.4 25892 294 15
2014-09-29T06:29:52 23369.2 25892 286 15
2014-09-29T06:30:24 23401.1 25892 277 15
2014-09-29T06:30:56 23433.0 25892 357 15
2014-09-29T06:31:28 23464.9 25892 1844 15
2014-09-29T06:32:00 23496.8 25892 1836 15
2014-09-29T06:32:31 23528.5 25952 1829 15
2014-09-29T06:33:03 23560.2 25952 1818 15
2014-09-29T06:33:35 23592.1 25952 1836 15
2014-09-29T06:34:07 23624.0 25952 1836 15
2014-09-29T06:34:39 23655.8 25952 1836 15
2014-09-29T06:35:11 23687.7 25952 1848 15
2014-09-29T06:35:43 23719.6 26048 1832 15
2014-09-29T06:36:15 23751.5 26048 2000 15
2014-09-29T06:36:46 23783.4 26048 2000 15
2014-09-29T06:37:18 23815.2 26048 2000 15
2014-09-29T06:37:50 23846.9 26048 368 15

You’ll see that I’m recording:

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

Compare that to the smart meter data:

DateTime Hour KwhUsage Cost Rate
2014-09-29 05:00:00 5 0.29 $0.02 $0.075
2014-09-29 06:00:00 6 0.31 $0.02 $0.075
2014-09-29 07:00:00 7 0.59 $0.04 $0.075

Not much data there, is there? Certainly not enough resolution to tell if a kettle has been running.

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:

  Power Monitor ndToronto Hydro Smart Meter
Day First Reading / Wh Last Reading / Wh Total Consumption / kWh No of readings Daily Total / kWh No of readings
2014-09-29 23896 43668 19.772 2711 19.77 24
2014-09-30 43668 52500 8.832 2710 8.82 24
2014-10-01 52500 68004 15.504 2711 15.51 24
2014-10-02 68004 81996 13.992 2712 13.99 24

The difference looks to me like aliasing; THES’s reporting is much more granular.

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!

smarter meter

I just signed up for Toronto Hydro‘s Time-of-Use (TOU) Metering programme. While it was mentioned in this month’s PowerWISE (hey, am I the only one who reads the info inserts that comes with their bill?), it doesn’t seem to have been officially launched.  On first look, it’s fairly nifty (click the image for a full-sized view):
daily TOU breakdown hourly
Since I’m a Bullfrog customer, I don’t think I get charged TOU rates (hey, it’d be nice; actually, if coupled to current capacity, I’d make hay while the sun shines/wind blows/water flows …) but at least I get to see the data. I wonder if the front end is scriptable? I’d love to be able to track my usage day by day.

(And to think, yesterday I was on the cusp of buying a Black & Decker Power Monitor. If it had ethernet/wireless/bluetooth, I’d have been on it like an X on a Thing That X Likes. It looks a bit complex to install.)

barefoot hydrodynamics

Ever since I discovered them, I have been fascinated by the Foxfire books. Not that I’m planning to go back to the land or anything, just they they often display flashes of ingenuity and craftsmanship.

Take this, for example:

tub wheel - from foxfire 2

It’s clearly a turbine runner, but it’s made from a slab of solid pine, pinned together then held in compression by steel bands around the rim.

sam burton chisels out a tub wheel bucket

It was made by Georgia craftsman Sam Burton, and is documented in Foxfire 2 (Wigginton et al, 1973, pub. Anchor Books, ISBN 0-385-02267-0, pp. 142-163).

Energy Saving Tips for Canadians, #1: a name thing

Canadians are remarkably profligate in their energy use, and I think I know why. It’s not to do with the oft-cited scale of the country, the size of our houses, our cold winters or our hot summers, it’s something simpler than that; it’s what we call our electricity.

Power here is generally known as hydro, and with it comes images of tree-lined rivers with bears happily fishing for salmon. Local electricity companies tend to have that watery thing in their name: Toronto Hydro, Hamilton Hydro, London Hydro (Crieff Hydro is something quite different, though). Some happy green images, eh?

I propose that we stop using the term hydro, and replace it with the snappier smog belching, nuke leaking, only fractionally hydro. It’d certainly make yer average Kathy or Doug drop their double-double (or donut, or dumaurier) when they got their smog belching, nuke leaking, only fractionally hydro bill in. Energy use would plummet, and at no cost to anyone!

Debunking the 25% Myth

My dad called yesterday, asking, “Wind turbines do run for more than 25% of the time, don’t they?”. Seems he read an opinion piece in his favourite fair ‘n’ balanced rag (The Telegraph) that said that wind turbines only run 25% of the time.

I see this factoid popping up more and more from the anti-wind crowd. It’s a particularly difficult one to refute in the press, as by the time you’ve tried to explain the difference between capacity factor and operation time, you’ve lost them. Or gone over your allotted time/word count, at least.

I’ve got a year’s production data from WindShare/Toronto Hydro‘s turbine in front of me. It’s on a marginal site, one that probably wouldn’t be developed by a commercial entity. So, does it run for more than 25% of the time?

Yes; the turbine is generating 63% of the time. I’ve defined generating as providing a net export of power to the grid. Our turbine’s a bit more cranky than most, and I have a suspicion that our metering system is dropping some production, but even so, 63% is way more than the claimed 25%. So it gives me great pleasure to say:

MYTH: Wind turbines only run for 25% of the time.
BUSTED! Wind turbines run at the very least 60% of the time, usually more.

(I can’t guarantee that Country Guardian won’t quote me out of context. I could make a cheap shot about not blaming them for their paymasters in the nuclear industry requiring value for money, but I won’t …)