The beauty of sailboats is that they don't require power in order to move. However, modern-day sailboats have a host of onboard electronics that do require power: Navigation lights, radar, a VHF radio, a GPS unit, the navigation console, interior lighting. These are typically powered by batteries, which are charged by an auxiliary motor if the boat has one, or the boat can be plugged in at the dock.

However, a Belgian startup called Phileole has invented an alternative: This Grain Blanc wind turbine.

This can be bolted to the mast. Because of its vertical orientation, it can capture wind from any direction. And unlike having to fire up the motor, it operates silently.

It's a lot bigger than it looks in the photos, by the way. It's just over 42" tall and just under 18" in diameter.

One unit can generate about 2.4 kWh per day, which is enough to power lighting, navigation equipment, the radio and the autopilot, with juice left over to charge laptops or phones. And of course, yu can add multiple units if you need more juice.

Though the device was designed specifically for sailboats, the company also sells bundles of them for buildings and homes in Europe.

The company notes that the units are made primarily from recycled polypropylene, and are 95% recyclable themselves.