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KWH , Watt giving me a headache... Answered

Morning Guys

Need a bit of help with the maths.

Hoping to run a fridge on a inverter / battery / solar panel. If it has a energy consumption of 0.43 KWH, I think it would be about 43 watts not sure here. What size battery and solar panel would I need?

Big Love



4 years ago

I was hoping kwh was a typo.

A four hundred thirty watt hour used per day would suggest the fridge runs on only eighteen watts.

Jack A Lopez

4 years ago

I think if you understood the difference between energy and power, and the different units used for these, this would bring you closer to enlightenment.


Another step on the path, is the realization that quoted numbers do not always provide a complete, or truthful, picture of what's really going on.

The best way to get good numbers, is to measure them yourself, provided you have the ability to do this.

Anyway, you have thrown a single number at us: "0.43 KWH"

I am going to guess KWH stands for "kilowatt*hour", a unit of energy.

So what does that mean? Is 0.43 KWH the amount of energy your fridge uses in one hour? Is it the amount of energy your fridge uses in one day?

Maybe you are waiting for someone on this forum to answer that question for you?

However, if you actually have this fridge in your possession, and you have a power measuring tool (like the Kill-A-Watt brand, or similar) then it turns you are in a better position for to discover the truth of how much power, equivalently energy per unit time, your fridge is using, than are the people on this forum who can only see your fridge in their imaginations.


4 years ago

A refrigerator using 0.43 kwh is using 430 watts.


4 years ago

First off battery capacity is calculated in amp-hours. You can convert to Watt-hours by multiplying by the batteries voltage. Secondly is that a daily power consumption? Seems pretty low unless this is a mini fridge.

I've done some quick and dirty calculations with a lot of assumptions but it should give you an idea of what the calculations roughly are.


4 years ago

Actually 430 watts, check out DIY Solar Jon's instructable for the calcs