How Much Solar Do You Need on a Boat?

This is one of the most common questions new cruisers and liveaboards ask. The answer depends less on boat size — and more on how much power you actually use each day.

Refrigeration, Starlink, lighting, and especially air conditioning can dramatically change your solar requirements.

A Typical Cruising Boat Daily Usage

That means many cruising boats use somewhere between:

4,000 to 8,000 watt-hours per day

And that's why many real-world cruising boats carry:

The Problem

Most people guess wrong.

They either install too little solar and run the generator constantly — or they overspend on equipment they don't actually need.

The Easy Way to Find Your Number

Instead of guessing, you can simulate your exact setup.

Try the Boat Power Simulator

Real Example

A liveaboard running refrigeration, Starlink, and occasional air conditioning might use:

With those settings, the system may last overnight — but struggle during cloudy weather.

That's exactly the type of scenario the simulator helps you test.

Try your own system here:

Open the Simulator

Related Guides