Adelaide Local Meeting's power use - then and now

Summary of bills (2007)

Period

kWh used

$

greenhouse gas emissions (tonnes CO 2)

July , August, September

879

184.76

0.88

October, November, December

331

86.82

0.34

January, February, March

277

79.79

0.29

April, May, June

369

93.76

0.38

TOTALS

1856

445.13

1.89

 

The table above shows how much fossil fuel electricity we used in 2007.
 
   
Production for PV panels and grid power usage, 2009-2011
Period
kWh drawn from the grid over the quarter
kWh exported from PV panels over the quarter
Greenhouse gas emitted by grid power usage (tonnes CO 2)*
April, May, June 2009
534
64
0.37
July , August, September 2009
516
428
0.51
October, November, December 2009
394
706
0.39
January, February, March 2010
294
745
0.28
April, May, June 2010
398
429
0.37
July , August, September 2010
503
391
0.46
October, November, December 2010
255
688
0.23
January, February, March 2011
239
675
0.22
 
 

*As shown on the electricity account for the mains electricity used at times the PV panels were not producing (night, overcast conditions, or when our draw exceeds our generation). Note, however, that as we export more solar power into the grid than we extract, the panels could be considered to offset the entirety of our power carbon footprint.

 
   
Annual summaries
 

kWh drawn from the grid over the year

kWh exported from PV panels over the year

Greenhouse gas emitted by grid power usage (tonnes CO 2)*

Did we export enough solar power to offset our grid use? Was there any extra export above that offest, and if so, how much?
2007
1856
1.89
No
2009
1738
1943
1.55
Yes, fully offset. Yes, extra 205 kWh exported
2010
1395
2183
1.23
Yes, fully offset. Yes, extra 788 kWh exported
 
   

The Meeting House uses power over the entire 24 hour perod, and solar energy is only produced in daylight hours. Even so, the table above shows a reduction in our draw from the grid of over 25% compared to 2007 and a large export to the grid that occurs during the daytime when there is little draw on power.

Most night-time power uses such as lights have already been converted to low energy globes, so items with a steady draw are the probable cause of the resistant grid draw. As the HWS is only switched on "on demand" the most likely appliance to further reduce grid draw would the the refrigerator. This will be replaced with a more energy efficient model when it reaches the end of its life.

 
   

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© 2009 Religious Society of Friends: South Australia Regional Meeting