40 MW XFR vs 20 MW Turbogenerator 6

[Okpower]

Hi all:

I have to do a presentation for the management team about a comparison between two options for a petrochemical plant electrical feeding:

1.- To buy and to install a 40 MW, 34.5/13.8 KV XFR with its correspondent 34.5 KV transmission line (3 Kms), to feed the main substation.

2.- To buy and to install a 20 MW, 13.8 KV Gas Turbogenerator in the same main substation.

I can say that I am pretty clear with the technical comparison, advantages and disadvantages.

But I need a solid economic data (basically initial cost of the two options, i.e. initial investment) to do a good presentation. I know this is the first point that the management would want to evaluate,and analyze to finally decide the best option.

Can anybody help me tu supply the initial investment, or initial cost comparison between the two options.

Thanks in advance

 

[jghrist]

There are so many variables that you cannot expect to get a solid cost estimate for free from a public forum. I would expect that a solid cost estimate for the two alternative would itself cost thousands of dollars.

It's far from obvious that the initial cost is an adequate basis for economic comparison anyway. What is the purchase cost of energy vs fuel and O&M cost of generation?

Why do you need a 40 MW (sic) transformer if a 20 MW generator is adequate?

 

[waross]

One or two percent difference in fuel cost will soon pay for the more efficient option.
Example;
Some years ago, Caterpillar was pushing the purchase of their new generation of more fuel efficient diesel generators on the basis that the fuel savings over the older sets would be enough to make the payments on the new set. This was in the 1 MW to 2 MW range of diesel generators.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rbulsara]

Agree with the above...you will need to invest time and money to come up with a reasonable estimate..never mind a solid one and a life cycle cost comparison.

Rafiq Bulsara

http://www.srengineersct.com

 

[Okpower]

Thanks for your answers. Actually, I could use a good approach, for just initial investment (cost of the XFR and the TG) e.g
, "the option 1 could be 200% the option 2" or "the 20MW turbogenerator cost the same than a 40 MW XFR".
Jghrist, the 40 MW XFR could be installed to have future power capacity. The 20 MW TG could be installed as initial power supply (by some couple of years).

 

[desrod]

Once again, depending on where you are, the best choice might be quite different.

In Canada, you can you get credit from the utility for the line and transformer not for the turbogenerator. Utilities do want your business and are ready to help you for that. Does-it apply to your situation?

Do you need any on-site emergency supply that you will need?
Can you sell back some energy/power?
What level of reliability do you want? How do you plan to operate when maintaining you generator? You might need more than 1 unit....they do fail and repair time might be longer that repairing a line. What is the cost of not operating?

Complex study. Hard to give you good advice in a forum.
Daniel

 

[waross]

Further to my last post, you may want to consider the annual cost of buying grid power and the annual cost of buying fuel for the turbo. Consider also the price stability of both options.
Consider;
10 MegaWatts average load at $0.08 per KWHr is about $7 millions per year. You may want to do a fuel cost estimate based on the actual fuel and electricity costs over the last few years. This could well be more important than initial cost.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[rmw]

Have you contacted ANY turbogenerator vendors or X-former vendors? That would be a better place to start than a public forum with a lot of anonymous contributors, notwithstanding the experts that we are...

Once you have contacted tham and have some facts and a group of questions generated by these facts, then a forum like this can be valuable. Not at the 'how high is up' stage.

rmw