Making Ice – A Technical Discussion

Matilda derives her energy for all shipboard systems from diesel fuel. Today I was explaining to Fiona the energy requirement to make ice for cocktails. At first, she said she didn’t care how much energy was required, either we have ice for cocktails or we sell the boat. As I continued to explain the physics to her she said, “Why don’t you just write a blog about it, I’m doing my Sudoku right now”. So, lucky reader, here it is.

It requires 4180 joules of energy to cool one kilogram of water by 1 degree centigrade. Keep in mind, you also have to cool the ice tray itself and, in fact, the entire freezer which is no easy task. Now, one liter of diesel fuel contains about thirty-eight million joules of energy. However, we must first convert the fuel into kinetic energy, then to electricity, then back to kinetic energy which is all very inefficient.

I’m no math whiz, but by my calculations it will require about 150 gallons of diesel fuel to make an ice cube. When I presented this information to Fiona at first she said she didn’t care. Then she said that I had obviously missed my calculations by several decimal points. She may be right.

Suffice it to say that it takes a lot of energy to make ice, but it will continue to be made aboard Matilda in quantities sufficient to make daily cocktails. Next week I will calculate the energy requirements for the three air conditioners and the sea water to fresh water processing system on Matilda. The Saudis are going to need to ramp up production.

I believe that solar panels may be a good investment.

9 thoughts on “Making Ice – A Technical Discussion

  1. Kevin Coomer

    I agree with Fiona. Keep buying fuel and never forget to TOP OFF the tank Before every trip. Especially the long ones.

    Cheers to you both. Safe travels.



    Well bless my soul, I was chuckling at the beginning of the blog until I reached Fiona’s comment: “Either we have ice for cocktails or we sell the boat.” That gave me a laugh out loud! The funniest things are SO true, and clearly Fiona was speaking her truth here. Respect.
    I love you guys, thanks for sharing your incredible journey with us!
    Nautical carpe diem= “Seas The Day!”


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