hoehater t1_iu4hrdy wrote on October 28, 2022 at 2:17 PM

Reply to comment by BirdUp69 in World’s 1st bulker powered by wind sails into Port of Newcastle by edweirdmuybridge

There are so many things wrong with that idea it’s not even funny, but the short answer is that there would be multiple points of loss in such a system making the entire arrangement incredibly inefficient compared to sails.

Keep in mind that sail used on these big ships aren’t simple pieces of cloth like ships used thousands of years ago, they’re air foils much like the wing of a plane. This means they can exert a LOY more force than you might think depending on wind direction and speed in relation to the ship. Fun fact: modern sail boats can achieve speeds 3-4 times that of the wind under the right conditions.

BirdUp69 t1_iu5b0en wrote on October 28, 2022 at 5:33 PM

Would be interesting to see a comparison across all wind conditions. And the installation/maintenance costs would also make for an interesting comparison

hoehater t1_iu5izhl wrote on October 28, 2022 at 6:27 PM

Wind turbine are generally far less then 50% efficient at turning the kinetic energy of wind into mechanical energy, most are under 40%. The theoretical maximum is about 59%.

Losses from the transmission and generator are 10-20%.

Losses from power transmission and conditioning would be another 5-10%.

Losses at the electric motor would 3-5%.

The loss of most boat props is between 20-40%.

Then there’s the issue of forces on the ship caused by a wind turbine, by design would be working AGAINST the motion of the ship with anything except a tail wind.

So yeah, it would be totally useless.

BirdUp69 t1_iu6oppk wrote on October 28, 2022 at 11:29 PM

What about directly driving the prop, mechanically?

hoehater t1_iu79zme wrote on October 29, 2022 at 2:23 AM

With what? A wind turbine? That would be like blowing into your own sail, just like using it to drive an electric motor.