# When making energy decisions, educate yourself first.

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Ozone
Status: Member (Offline)
Joined: Feb 11 2011
Posts: 3
When making energy decisions, educate yourself first.

I read an interesting note from one of my wife's friends, on Facebook. It was along the lines of "You know your parents are getting old when you come home to a dark house and your dad is walking about using a torch, to save on the energy bill".

Ok, so have a laugh at dad's expense, while demonstrating that those on or approaching pension age have a very different viewpoint on costs compared to the young and frivalous. That, whilst an important distinction, is not the subject of this mail. What I considered was, is her father saving money?

I looked up torches on line and found a good quality LED torch that runs for "100 hours" on 2 litium cell batteries. These batteries sell for \$6.50 a pair. If my maths is correct, that's 6.5c per hour of use.

The lights in my house are 23W globes (these burn about as bright at the old 100W incandecents), the one in my garage is only 11W and in my sons room, I have a 5W globe (quite dim, same as old 25Watter, so I can turn it on at night to check in on him without waking him ... he is only 1 year old) So, 23W, left burning for 1 hour is 23Whrs (Watt hours) .. or 0.023kWHrs (kilo Watt hours). In my area, 1 "unit" of electricity costs 20c (ie: 1KWHr = \$0.20) which means that this very very bright light is burning up less than 0.5c per hour.

To me, this means that the battery powered torch is 10 to 15 times more expensive to operate, for the same amount of time, than the grid supplied light globe, not to mention providing far more light, which, as you age has to be considered a safety bonus compares to walking around in the dark with a torch. The simple reasoning is that grid power is supplied in bulk, whilst batteries are small packages of power, bought in tiny indvidually wrapped containers, and we all know about the savings associted with buying in bulk.

Yes, her father had a neat idea, and maybe there are cheaper torches available out there (especially a solar powered torch or a torch with a built in generator). The option to buy power in battery form, however, may seem cheap, but in reality, it's very expensive.

The simple lesson to learn is that you need to educate yourself and make intelligent decisions on energy savings.

Damnthematrix
Status: Diamond Member (Offline)
Joined: Aug 10 2008
Posts: 3998
packaged energy

I remember reading in a david Suzuki book (before LED torches came to be!) that the energy in small batteries costs 750 times as much as grid electric energy.....!

Mike

Ozone
Status: Member (Offline)
Joined: Feb 11 2011
Posts: 3
And the rest....

Down here, you can buy AA batteries for \$29.95 for a pack of 24. These are 1.5V and may be up to 2900 mAh batteries. (2900 mAh is the top end estimate for Alkaline batteries)

2900mAh at 1.5V = 0.00435kWh, so for \$1.25 a battery, you are looking at about \$287 a KWH, compared to 20c for grid connected power. Thats over 1400 times more expenisve!