We will typically size a system with enough power to achieve hull speed.  For example, the QuietTorque 10.0 system has enough power to drive most sailboats up to 30 feet at hull speed. An electric 10 kW system can replace a diesel or gas engine of about 20HP.  Any loss in range and speed is more than offset by the Clean! Green! Quiet! and the immediate “right now” power of an electric system.