# What size generator would I need if I had no batteries?

1210 Views 8 Replies 6 Participants Last post by  Rbertalotto
I want to run a 50hp electric motor on a snow blower on a truck. It may sound crazy, but let’s talk theory here for a second. To make power transmission easier than 30gpm hydraulic units with 50hp ICE motors, can’t I just run a generator to spin the motor?

My math looks like I need a 60kw generator to power a 50hp electric motor??? For real?? That’s huge.
1 - 9 of 9 Posts

#### kennybobby

· Registered
Joined
·
1,955 Posts
Just like in school, you have to show your work on math problems--can't just throw out a number.

Are you using 0.746kW per Hp?

But it's not clear how you improve the situation:

from 50hp ICE driving 30gpm pump,

to 50hp ICE driving 50hp generator driving 50hp electric motor driving 30gpm pump?

#### Jason is Crazy

· Registered
Joined
·
12 Posts
Discussion Starter · ·
Perhaps I explained myself all wrong lol.
The basis of the question is: I wish to power a 50kw electric motor without batteries. Does that mean I need a 50kw generator?

#### kennybobby

· Registered
Joined
·
1,955 Posts
If you could get 100% efficiency, then yes. But to allow for the real world losses you would need a larger generator, for example 63kW for an 80% efficiency.

#### brian_

· Registered
Joined
·
8,498 Posts
But it's not clear how you improve the situation:

from 50hp ICE driving 30gpm pump,

to 50hp ICE driving 50hp generator driving 50hp electric motor driving 30gpm pump?
No, the idea is to drive a snowblower. Instead of a transmission system consisting of a hydraulic pump and motor, the proposal is to use an electric generator and motor. The electric components would replace the hydraulic components, not be added to them.

So
from 50 hp ICE driving 30 gpm pump driving hydraulic motor driving blower
to 50 hp ICE driving generator driving electric motor driving blower

#### BVH

· Registered
Joined
·
47 Posts
What is the nameplate data on the electric motor. Need Voltage and Amps requirements and be sure Frequency matches.

#### brian_

· Registered
Joined
·
8,498 Posts
Are you really using a separate engine for this, or is the pump of the existing system driven by a PTO on the truck's engine or transmission? I assumed that snow blowers with their own engines used on loaders and airport runway clearing equipment usually drive the blower directly from the engine, not via hydraulics.

Neither hydraulic pumps and motors nor electric generators and motors are perfectly efficient. If the electric stuff is more efficient than the hydraulic stuff, less engine power would be needed; if the electric stuff is less efficient than the hydraulic stuff, more engine power would be needed.

The idea of an electric drive without a battery is the same as a diesel-electric locomotive or most diesel-electric or turbine-electric ships. The details depend on design choices (such as AC versus DC generators and motors), but regardless of the details the power output is the power input minus the power lost to inefficiency.

Yes, a traditional 50 kW engine and generator set is huge, because it uses century-old technology.

#### john61ct

· Registered
Joined
·
1,080 Posts
Why use an electric motor?

#### Rbertalotto

· Registered
Joined
·
54 Posts
Kind of like a diesel locomotive or a huge off road dump truck or a modern ocean liner........Engine driving generator driving electric motors...I get it!

1 - 9 of 9 Posts