Joe Blake
14th July 2012, 21:41
Partially as a result of a pretty fierce storm a few weeks ago that knocked out the grid for 24 hours, I bought a new refrigerator to replace my 15 year old chilly box (Fridge/freezer). For the past 3 years or so I'd been keeping it chuffing along by putting 4 litres of ice in it every morning from the camping freezer (12/24/240 volts) which runs directly off the sun (most times anyway - via batteries).
I am an inveterate tinkerer and I have been monitoring the power performance of the fridge and arrived at the following figures. Over 9 days the old 240 volt fridge consumed 7.5 kWh.
The new fridge, although it does not have its own freezer, is actually of larger capacity than the old. I put the watt meter on it from day 2 (giving it a day to reach operating temperature - 4 degrees Centigrade - via a digital thermometer). I started the daily ice bottle routine immediately, and after 14 days the figures were 3.0 kWh of power consumed.
I then ceased putting in extra ice and after 14 days 4.0 kWh of power had been consumed.
The old fridge has been de-gassed and is in the process of being turned into a raised vegetable garden, so I can't do any comparison with the old banger not using extra ice.
Given that there is only one person using the fridge, and didn't alter their lifestyle over the period, the figures derived would seem to be comparable.
So for those who like statistics, a summary:
Standard electricity tariff: 21.87 cents per kWh.
15 year Old fridge (with extra ice daily): 0.83 kWh/day = 18.1 cents/day
New fridge (with extra ice daily): 0.21 kWh/day = 4.59 cents/day
New fridge (without ice daily) : 0.28 kWh/day = 6.12 cents/day.
Obviously with the 240 volt fridge(s) running off solar power during the day from my rooftop panels, seems hard to justify buying the 12/24/240 volt freezer and associated gubbins such as PV panels and batteries purely from an economics point of view, but given that on more than one occasion of grid failure over the past few years I've been able to maintain the fridge at a reasonably low temperature, and therefore not had to throw out spoiled food, it makes a modicum of sense. After the last major power outage, if I'd had to replace food because of spoilage I'd have been looking at something in the vicinity of $80 or saved (I had food in the camping freezers as well), and the old adage, "a penny saved is a penny earned" could apply here.
If nothing else it certainly gave me a practical insight into the efficiency of newer refrigerators compared to those of the last century.
Joe
I am an inveterate tinkerer and I have been monitoring the power performance of the fridge and arrived at the following figures. Over 9 days the old 240 volt fridge consumed 7.5 kWh.
The new fridge, although it does not have its own freezer, is actually of larger capacity than the old. I put the watt meter on it from day 2 (giving it a day to reach operating temperature - 4 degrees Centigrade - via a digital thermometer). I started the daily ice bottle routine immediately, and after 14 days the figures were 3.0 kWh of power consumed.
I then ceased putting in extra ice and after 14 days 4.0 kWh of power had been consumed.
The old fridge has been de-gassed and is in the process of being turned into a raised vegetable garden, so I can't do any comparison with the old banger not using extra ice.
Given that there is only one person using the fridge, and didn't alter their lifestyle over the period, the figures derived would seem to be comparable.
So for those who like statistics, a summary:
Standard electricity tariff: 21.87 cents per kWh.
15 year Old fridge (with extra ice daily): 0.83 kWh/day = 18.1 cents/day
New fridge (with extra ice daily): 0.21 kWh/day = 4.59 cents/day
New fridge (without ice daily) : 0.28 kWh/day = 6.12 cents/day.
Obviously with the 240 volt fridge(s) running off solar power during the day from my rooftop panels, seems hard to justify buying the 12/24/240 volt freezer and associated gubbins such as PV panels and batteries purely from an economics point of view, but given that on more than one occasion of grid failure over the past few years I've been able to maintain the fridge at a reasonably low temperature, and therefore not had to throw out spoiled food, it makes a modicum of sense. After the last major power outage, if I'd had to replace food because of spoilage I'd have been looking at something in the vicinity of $80 or saved (I had food in the camping freezers as well), and the old adage, "a penny saved is a penny earned" could apply here.
If nothing else it certainly gave me a practical insight into the efficiency of newer refrigerators compared to those of the last century.
Joe