What is a Kilowatt (kW)?

Lyall Burgess

Sep 1

2 min read

No, we're not talking about that corporate cartoon character Reddy Kilowatt! It's that as more and more boats are going solar we're starting to see an increase in the average size of the solar system aboard. From smaller 200W-400W systems we're now seeing larger catamarans in particular with over 2,000W systems. You may see this written as a 2kW system, but what is a kW and how is it different from a W?

It's simple: 1 thousand Watts equals 1 Kilowatt.

1 Kilowatt (kW)	1,000W (1 thousand Watts)
1 Megawatt (MW)	1,000,000 Watts (1 million Watts)
1 Gigawatt (GW)	1,000,000,000 Watts (1 billion Watts)
1 Terawatt (1TW)	1,000,000,000,000 (1 trillion Watts)

Large solar arrays on the aft of many catamarans

Here's just a few examples of larger installs from our install list:

Fountaine Pajot 44 with 5x415W-R. That's 2,075 Watts or 2.07kW
Lagoon 500 with 6x370W. That's 2,220 Watts or 2.22kW
Leopard 44 with 4x470W. That's 1,880 Watts or 1.88kW

It's simple: 1 thousand Watts equals 1 Kilowatt (kW)

When working with power it's often easier to work in watts (instead of amps) even if you have a 12V battery or maybe a larger 24V or 48V battery bank aboard, or even if you're talking about devices powered off 110V (whilst on shore power or via your inverter or generator). It keeps all the numbers in check and when you do a power audit you will find the labels on devices often have it written in watts.

A good analogy would be how fast you travel in your car. At a given moment you might be travelling at say 65mph, so in one hour you will have travelled 65 miles. If your solar array is rated at 1,000Watts then in one hour you will have produced 1,000Watt hours (given good conditions/lots of variables)