Efficency of a diesel generator

what is the efficiency of a diesel generator? I have to find that out and I have worked out that 1 MJ costs 2.61p and I have to then work out the fuel cost per kWh of the electricity produced?

ALL HELP APPRECIATED! THANKS :*

Reply 1

username1560589

Original post by itsyahg

Work out what a kWh is in MJ, then it's just a simple conversion.
edit: Estimate the efficiency.

(edited 8 years ago)

Reply 2

itsyahg

Original post by morgan8002

Work out what a kWh is in MJ, then it's just a simple conversion.
edit: Estimate the efficiency.

I think that 1 kWh is 3.6 MJ, oh right so if I used eg, 60% efficiency, what would I do with that 60%? x

(edited 8 years ago)

Reply 3

username1560589

Original post by itsyahg

I think that 1 kWh is 3.6 MJ, oh right so if I used eg, 60% efficiency, what would I do with that 60%? x

Yes. You'd use it to calculate the output energy, using

E_{out} =\epsilon E_{in}

, where

\epsilon

is efficiency.

Reply 4

itsyahg

Original post by morgan8002

Yes. You'd use it to calculate the output energy, using

E_{out} =\epsilon E_{in}

, where

\epsilon

is efficiency.

okay then, i'm still quite confused what the energy input and output would be? x would I do 45.5 MJ (calorific value for diesel) x 60?

(edited 8 years ago)

Reply 5

username1560589

Original post by itsyahg

okay then, i'm still quite confused what the energy input and output would be? x would I do 45.5 MJ (calorific value for diesel) x 60?

Remember it's 60%, so you would multiply be 0.6, not 60. The input energy would be the energy per penny in cost, because you want to find the output energy per penny in cost.

Reply 6

itsyahg

Original post by morgan8002

Remember it's 60%, so you would multiply be 0.6, not 60. The input energy would be the energy per penny in cost, because you want to find the output energy per penny in cost.