[Notice: the thumbnails of the graphs are very ugly, I'm still looking for a way to make that better looking without too much work. I you click on the thumbnails a larger version of the graphs will be displayed.]

Ever since I have had my ‘own’ water, gas and electricity meter (no more shared meters) I have noted my consumption. On this you’ll find an overview of our energy consumption since the end of 2004.

Electricity:

We have energy efficient appliances, no dryer, compact fluorescent and LED-lighting, laptop computers, quite a few plug switches which eliminate standby power nearly completely, and the most important component: energy conscious inhabitants. All those things have allowed us to lower our electricity consumption to about 900kWh per year (2009), which is very low for a two-person household. During the winter months the consumption is usually a bit higher because the central heating system runs more, the lights are on longer and my girlfriend uses an electric blanket. During holidays we switch off all electrical equipment (except, obviously, the solar panels) so there’s usually one summer month with a very low consumption.

Solar power:

We installed our first 555Wp of solar panels in June 2006. At the beginning of 2007 the installation grew to 855Wp, and with our move to our own house, in the beginning of 2008, we had the installation extended to 1365Wp. In February 2009 in installed a small 100Wp panel as an awning above our front door, bringing the total op tu 1465Wp. The final extension in April 2010 added a 660Wp installation, for a final total of 2125Wp. Since January 2010 I am able to measure the production of all the seperate installations. The seasonal trend is very clearly recognisable in the graph:

Drinking water:

I started measuring the drinking water consumption later than the others, as the water meter in our rental apartment was located quite inconveniently. It is one of the most stable quantities I measure, except for 2006 when my girlfriend spent six months out of the country. March 2010 shows a large spike, this is the result of an unfortunate incident in which the water tank of the toilet did not close after flushing, letting water flow for a whole day.

Natural gas:

Our rental apartment, where we lived from the end of 2004 to the end of 2007, had a somewhat  energy efficient central heating system and average insulation levels. The house we bought in the beginning of 2008 was built in the ’30s, and as such not brilliantly insulated although all windows have double pane glass and the central heating is quite new and efficient. Those factors just about cancel out because our natural gas consumption did not change significantly after our move. Of course the seasonal changes in the natural gas consumption are clearly visible in this graph.