What size of dc/ac electrical motor would i need to match a 715hpm diesel engine?

Question

The engine would be for a boat so another question i have is does anyone have any idea how to calculate or figure how many kw it would take to run a dc motor like that obviously it would not be running at 715 hp the whole time because that is only needed for acceleration. Thank you!!!!!!!

Answer 1

this must be a big boat.

715 HP converts to 533 kW by my calculator.

Usually an electric motor can be smaller than an equivalent gasoline engine as it has a wider torque range.

and now you see why electric cars are so difficult to make. If you used a 100 kW motor, 150HP, you would need hundreds of pounds of batteries to run it for an hour.

1 large battery has 1kw-hr of power. 100 of these would give you 100kW-hrs, enough to supply a 100kW motor for 1 hours. At a weight of maybe 2000 pounds.