General Information
Sunrise07:38
Sunset18:06
Temp. Outside9,2 °C
Temp. Inside22,7 °C

Usages for today
Gas0,00 m3
Power0,1 kWh
Water0 L

HA Statistics
Devices 292
Device values 1723

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How to measure power consumption

Using a RFXCOM RFXMeter and aRFXPulse module, i can count the pulse coming from a DIN-rail KWh-meter with S0-output.

Eltako WSZ12E-65A This is the Eltako DIN-Rail KWh-meter. This meter is DIN-rail mountable, so it's very easy to install this meter into the fusebox. It generates a pulse for every Wh that is being consumed. Counting these pulses is all that has to be done...

Remember, you can click the images to enlarge them. 
The Eltako kWh-meter built into the fusebox This is the KWh-meter as it is installed in my fusebox.
The fusebox This is my fusebox with the KWh-meter installed.

More information about the components used:

Eltako WSZ12E-65A specs (dutch)

RFXCOM RFXMeter with pulse counter
 
For measuring individual devices i have 2 Power Monitors like these:
BASETech Power Monitor
Ideal for measuring power usage of all the individual power consuming devices in your house. Just plug the power monitor in a the wall outlet, plug the power consumer to be measured in the power monitor and it starts measuring the power consumption.

This way it's easier to identify the big power consumers in your house, which makes it easier to see where your efforts in power usage reduction can have the best results.   

Power usage is stored in a SQL Server database on a hourly basis. So for every day that passes, 24 rows are written into a table. From there on it's very easy to create charts to display power usage for the last 1 or 2 days, but also more aggregated charts can be produced to display usage over a longer period and perhaps show trends.

Our nightly power usage used to be 550-600W. This was way to high! So when i got power usage visualised, i started doing something about it; basically switching off everything that could be switched off, especially at night. Here's where Domotica can be of great help;just let your Home Automation system know you're going to sleep and it can take care of switching off all devices you don't need while sleeping! This way you'll never have lights buring in the garage all night..

Another thing i did was get rid of 3 PC's that were running 24/7 and replaced them with 1 power efficient, yet fast server. It consumes around 70W, much less than the other 3 together. And it has more CPU power too!

Nowadays (August 2008) we still have a nightly power usage of around 300-350 Watt. That's still to much in my opinion! What is causing this?
A few ideas:

- My server that's on for 24/7;
- DSL modem, router, WiFi Access Points etc.;
- Mechanical ventilation;
- Central heating/boiler;
- Garage door opener;
- Lights outside;
- 2 fridges and a freezer;
- 2 alarm clocks;
- Bedroom TV on standby;

As you can see, there's still a lot that can be done to reduce our power consumption...

To be continued...