Renewable Energy Question? (Motor + Generator)

[kasco]

Hi      WILL IT WORKS?

1KW el mot 4000rpm powering true pulley 1:4 generator req. (1000rpm and 4kw power) to make 3KW el energy

generator will power the motor back 

yes i know there are some loss  so let say we need 2kw el. energy get 1kw power of el. motor 

and we need 4kw power to get 3kw  el energy                  is still 1kw spare or not?

 

[kme]

Unlikely.

You need the efficiency rating of the motor & genny........but unlikely to (combined) be 75%

Thats without taking into account transfer losses, heat, control gear, etc........

Any meaningful conversation would require more information - -specifically the efficiency ratings.

KME

edit: 1KW "spare"?? NO. what isn`t transferred is "lost" ( i.e. transformed into another type of energy.)

 

[steptoe]

am I reading this right,

you want to put something on the motor shaft [alternator] that will turn and thus give you electricity out ? windmill/waterwheel?

it doesnt work that simply,

I could be very wrong here though, its not easy understanding the post.  :|

 

[kasco]

1 kw spare should be electric energy 

 

[kasco]

am I reading this right,you want to put something on the motor shaft [alternator] that will turn and thus give you electricity out ? windmill/waterwheel?

it doesnt work that simply,

I could be very wrong here though, its not easy understanding the post.  :|

electric motor powering generator then generator powering motor back 

 

[poni]

noooooooooooooooooooooooooooooooooooooooooooooooooo!!!!

 

[steptoe]

it will never work,

too many losses,

nothing will work at 100% efficiency, and you are trying to get >100% efficiency , or have you got 2 motors?

remember that a generator used for powering a motor needs to be x3output of the motor rating for start-up inrush.

 

[kasco]

Motors are about 90% efficient at converting electricity to mechanical work.

Generators are also abpout 90% efficient.

to get 1kw power of motor then need 1.10kw el energy 

to get 1kw of el energy need 1.10kw of power

I'm not electrician is it ok?

 

[steptoe]

NO,

motors need about 250% to start,

and, I dont know where you get the idea they are 90% efficient, that is dependant on the motor.

 

[kasco]

from internet

Electrical motors constructed according NEMA Design B must meet the efficiencies below:

Power
(hp) Minimum Nominal Efficiency1) 1 - 4 78.8 5 - 9 84.0 10 - 19 85.5 20 - 49 88.5 50 - 99 90.2 100 - 124 91.7 > 125 92.4
Gen2.0 PremiumPlus+ Electronically Commutated Permanent Magnet (ECPM) Motors, from NovaTorque Inc., Fremont, Calif.—driven by variable frequency drives—offer motor-only rated point efficiencies of 93% and 92% for 3 hp and 5 hp versions respectively. By comparison, 3 hp and 5 hp NEMA Premium induction motors, when driven by variable frequency drives, achieve a motor-only efficiency of between 88.5 and 89%.

 

[kasco]

or what you think is real life efficiencies for motor and generator

 

[Andy™]

Hi      WILL IT WORKS?

1KW el mot 4000rpm powering true pulley 1:4 generator req. (1000rpm and 4kw power) to make 3KW el energy

generator will power the motor back 

yes i know there are some loss  so let say we need 2kw el. energy get 1kw power of el. motor 

and we need 4kw power to get 3kw  el energy                  is still 1kw spare or not?

erm... if it was that simple, do you really think it wouldnt already be done?

energy cannot be created or destroyed, only transformed.

 

[kasco]

all energy will be transformed to electricity is it?

 

[steptoe]

not all,

some of it will be transformed as heat etc.

there will be friction etc involved, this is where efficiencies come into play.

 

[ProDave]

Google "perpetual motion" and you will find all the answers.

 

[kasco]

yes 

not all,some of it will be transformed as heat etc.

there will be friction etc involved, this is where efficiencies come into play.

do you know how much  losses will be and efficiencies for motor and generator ruff

 

[steptoe]

could probably be about 99% losses without further information on the exact set-up

 

[kasco]

99% losses on motor that is 1% efficien so how much el energy you need get 1kw of power 1.99kw el e?

 

[Andy™]

99% losses on motor that is 1% efficien so how much el energy you need get 1kw of power 1.99kw el e?

99% losses mean you will need 100kw in to get 1kw out

 

[kasco]

numbers found off web sites sellers  

1- MOTOR efficiency of between 88.5 and 89% go for       80%     20%loss

2- PULLEY  loss of approximately 10%                                          10%loss

3- GENERATOR Typical efficiency values are 93-94%.      90%    10%loss

4- OTHER  heat . gravity. air                              idon't know           10%loss

all i think not will be more than 50%