This unit is a standard chest freezer but I added about 12 gallons of olive oil .
As you can see I used old plastic signs to keep the oil up against the cooling coils, I tried this with half liter water bottles but the fridge gets too cold ( 26f ) for the food.
Water has a heat of fusion of about 100, this means it takes 100 times as much energy to freeze 32 degree water as it does to raise water 1 degree from 32.
The problem with using water for a fridge is you will freeze your food if you try to use the heat of fusion of water to keep cool.
Olive oil has a heat of fusion of 48 but it starts to freeze at 40 degrees Fahrenheit, it also has one half the heat capacity of water , this means it takes 4 gallons of olive oil to hold as much heat as 1 gallon of water( at fusion temp), but it thaws at 32-40 degrees which means it will hold the refrigerator at 32-40 degrees for a very long time.
As you can see I have bottles of water and oil (I didn't have enough oil). It usually takes 1/2 hour to get from 40 to 32 degrees but it will stay at less than 40 degrees for a few days while unplugged.
This saves power and money by using the solar panels when the sun shines to make cold and then using the flywheel effect of the olive oil to hold it for long periods.
A regular fridge would need power at night, (which requires battery power) this system does not need batteries so your bank can be smaller.
By not using batteries you do not lose power on charge or discharge and can rig it to come on only when the batteries are fully charged.
To control temperature you can use a regular fridge thermostat and a battery powered timer to turn the fridge on at 3:00 pm or so for 1/2 hour.
The compressor runs at 180 watts so one half hour every day = 90 watt hours/day, I will update the power usage as I get more time using it.
4/29/11
This is in my sun room I will move it to a cooler area this summer or power consumption will go up.
Water has a heat of fusion of about 100, this means it takes 100 times as much energy to freeze 32 degree water as it does to raise water 1 degree from 32.
The problem with using water for a fridge is you will freeze your food if you try to use the heat of fusion of water to keep cool.
Olive oil has a heat of fusion of 48 but it starts to freeze at 40 degrees Fahrenheit, it also has one half the heat capacity of water , this means it takes 4 gallons of olive oil to hold as much heat as 1 gallon of water( at fusion temp), but it thaws at 32-40 degrees which means it will hold the refrigerator at 32-40 degrees for a very long time.
As you can see I have bottles of water and oil (I didn't have enough oil). It usually takes 1/2 hour to get from 40 to 32 degrees but it will stay at less than 40 degrees for a few days while unplugged.
This saves power and money by using the solar panels when the sun shines to make cold and then using the flywheel effect of the olive oil to hold it for long periods.
A regular fridge would need power at night, (which requires battery power) this system does not need batteries so your bank can be smaller.
By not using batteries you do not lose power on charge or discharge and can rig it to come on only when the batteries are fully charged.
To control temperature you can use a regular fridge thermostat and a battery powered timer to turn the fridge on at 3:00 pm or so for 1/2 hour.
The compressor runs at 180 watts so one half hour every day = 90 watt hours/day, I will update the power usage as I get more time using it.
4/29/11
This is in my sun room I will move it to a cooler area this summer or power consumption will go up.