You can put this solution on YOUR website! To do this calculation you need two additional constants, the heat of fusion and the heat of vaporization.
The heat of fusion is the amount of energy required to go from solid to liquid (333.6 J/g for water).
The heat of vaporization is the amount of energy required to go from liquid to gas (2257 J/g for water).
As you can see it takes about 7 times more energy to vaporize water than to melt the equivalent amount of ice.
The heat of fusion for 500g of water is 166.8 KJ.
The heat of vaporization for 500g of water is 1129 KJ.