Block Ice
If I put a block of ice in my refrigerator every day & left it on would the energy savings be worth $2 per day?
Of course the ice would have to be in a pot or something to keep the melt water under control.
Would the $2 a day spent on a block of ice be worth the effort?
A regular $2 bag of ice is about 2.7kg. Assuming the ice is at 0C it will take (2700g)*(80 cal/g)*(4.186 J/cal) = 904,176 Joules of energy to melt the ice.
1 Joule is the same as 1 Watt*second so it takes 904,176 Ws of energy to melt that ice.
Converting the watts to kilowatts and seconds to hours we get (904,176 Ws)*(1/1000 kw/w)*(1/3600 h/s) = 0.25 kwh of energy to melt your ice.
0.25 kwh of energy is worth around 2.5 cents.
So no, it won’t work. This method will put you out about $1.97 for every bag you put in (not to mention the gas and time spent buying the ice).
Someone is going to mention that you also have to take into account the ice actually being below zero and also it warming to the temperature of the fridge (around 5C) but these effects are small compared to the energy of melting.
