My Online Diary

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

Year	kWh/yr (household)	kWh/day	kWh/yr (per person)	kWh/day (per person)	Comments
2004	6524	17.9	3262	8.95	We 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
2005	5176	14.2	2588	7.1	Using Solar PV's to run all house lights from July.
2006	5160	14.1	2580	7.0	Added solar hot water system in June.
2007	5401	14.8	2400	6.6	Added 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).
2008	7132	19.5	2377	6.5	We 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.
2009	7336	20.1	2445	6.7	Well... we're not heading in the right direction. I haven't done anything to improve the house all year.
2010	7249	19.9	2416	6.6	No change.
2011	6990	19.0	2330	6.4	Very slightly better.
2012	7390	19.2	2463	6.4	No change.
2013	7236	19.8	2412	6.6	Very slightly higher.
2014	6970	19.6	2323	6.5	Switched 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

Year	kWh/yr	kWh/day	Source
1990	8510	23.3	IEA
2000	9071	24.8	IEA
2000	8723	23.9	World Bank
2001	8510	23.3	World Bank
2001	9264	25.4	IEA
2002	8831	24.2	World Bank
2002	9088	24.9	IEA
2004	10238	28.0	UN Development Reports
2005	9756	26.7	IEA
2005	9436	25.8	CIA 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.

Notes

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.

Interesting:

New Zealand electricity generation 2010

The rise of renewables, or so it seems - In the 2010 calendar year, a total of 43,401 GWh of electricity was generated in New Zealand, 74 percent of which came from renewable sources, up three percent from the previous year.
NZ electricity market overview
24hr NZ electricity usage, 24hr Wgtn electricity usage

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

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Page last modified on 08 January 2015 at 03:24 PM