Electricity Usage

I've been obsessively recording my household daily electricity usage since we moved in to first home in Jan 2004. We don't own a car or use gas or wood for heating - so our electricity use is a rough indicator of how our carbon footprint is trending.

Source: My raw Excel data updated daily
YearkWh/yr (household)kWh/daykWh/yr (per person)kWh/day (per person)Comments
2004652417.932628.95We started with standard electric heaters as our only heating source. I installed ceiling insulation in April, under floor insulation in June, and a heatpump in September
2005517614.225887.1Using Solar PV's to run all house lights from July.
2006516014.125807.0Added solar hot water system in June.
2007540114.824006.6Added wall insulation January-March. Experimental double glazing in June. Had a baby(!) in October and replaced washing machine with a more energy & water efficient front loader (which is getting a LOT of use).
2008713219.523776.5We used 32% more electricity this year than 2007. It doesn't look so bad on a "per person" basis, but - climate change is due to cumulative total emissions, it doesn't care about efficiency per person. Reducing our carbon foot print is hard.
2009733620.124456.7Well... we're not heading in the right direction. I haven't done anything to improve the house all year.
2010724919.924166.6No change.
2011699019.023306.4Very slightly better.
2012739019.224636.4No change.
2013723619.824126.6Very slightly higher.
2014697019.623236.5Switched my web server machine to a low power machine running off my solar system in October.

For comparison

Michael Lawley's house (four person living) averages under 5 kWh/day. He uses a wood burner for heating and has a much better designed and insulated house.

New Zealand electricity consumption per capita

2000872323.9World Bank
2001851023.3World Bank
2002883124.2World Bank
20041023828.0UN Development Reports
2005943625.8CIA World Factbook

I don't know whether these include industrial electricity consumption or not. It's interesting that the numbers are jump around so much. I assume different sources use different population numbers.


In 2007 we were averaging just over 14 kWh per day (8 kWh per day in summer up to 24 kWh in winter). 2008 we averaged 19.5 kWh per day - so we're heading in the wrong direction energy-wise. Although we are still well below the 8000 kWh threshold that makes us eligible for the "low user" discount.

My 2011 goal is to use less than the previous year. (Which feels like a pretty feeble goal.)

Our electricity usage includes all heating and cooking, plus the usual TV's, radio's etc. Plus an electric lawnmower and the web server that serves up this site. It does not include the weather station and it's laptop, which run off my solar PV panels.

Overseas readers may be interested to know that New Zealand's electricity supply in 2010 was 74% generated from renewables (mostly hydro* and geothermal). This means my electricity usage has a smaller carbon foot print here than it would in the USA/UK/Europe where a lot of electricity is generated from coal.


Attach:NZ-electricity-generation-2010.jpg Δ|New Zealand electricity generation 2010

Attach:wgtn-electricity-usage-by-hour.gif Δ|Wellington electricity usage by hour (1 June-25 June 2009) [Source:http://www.systemoperator.co.nz/zone-loadings]

Page last modified on January 08, 2015, at 02:24 am
Powered by PmWiki