oder wie bekommen wir mit unseren 650m2 Atelier/Werkstatt/Galerieflächen die Strom und Heizungskosten unter Kontrolle?

We need an energy monitoring system!

There's already a great open source software platform out there. It's call Volkszähler - it has nothing to with a census, it's a Zähler (meter) for the Volk (people). It can log all sorts of things like energy use, temperature, air pressure, humdity ....

More info about it here: http://www.volkszaehler.org/ (the website is mixed German / English. If you don't speak German, Google Translate is your good friend)

But afterall that's just software. How is the consumtion actually measured? With one of those things:

It fits snuggly on a DIN-rail, right next to the circuit breakers and it measures the electricity flowing through it. For every Watthour consumed it sends out a short impulse (on the two unconnected screw clamps on the left). This is called an S0-interface. The impulse can be detected by a NetIO from Pollin Electronics, an Arduino, or even a simple serial port. We'll be using a NetIO for greatest stability and flexibility.

Plus this meter also has a good old-fashioned rotary counter built in that can't be reset or tampered with, just in case someone doesn't trust the software ...

To test out the monitoring platform I've hooked one of those meters up to my server at home (using the serial port method). On the left side is a graph of its energy usage:

So my server used 2.39 kWh during the last 24 hours. Ouch! That's too much. I really need to do something about that - but when it's getting warmer outside. Right now I can make good use the heat given off by that thing ;) You can also clearly see the peak in the night when all the automatic backup-cronjobs fire off.

Since all that seems to work fine, we'll set up the larger version for our shared workspace soon. We'll keep you up to date on this page ....