Low Voltage Generator vs. Medium Voltage Generator

I'm not sure if I understand Option #1 exactly, but it sounds like there might be more maintenance involved. It sounds like six generators and six 3-phase transformers.

Even at a 10% increase in cost to go with Medium voltage generator, there should statistically be fewer problems, over time than an option with six generators.

It comes down to pay now or pay later and later again, .....

you got it right. in option # 1; 6 x 1.01 MW low voltage380 volts, 3 phase generator and 6 step up transformers + accessories such as synchronizing panel and ATS.

For option # 2; they offer 3 x 2.1 MW medium voltage generator (13,800 volts, 3 phase) + accessories such as synchronozing panel and ATS.

thanks for the suggestion.

regards,

dalton

Hi Dalton,

Operation cost (fuel consumptions) if synchronization set up properly, for option #1 is lower than option #2 as number of unit on line will depend on your load.

Maintenance cost should not be far for option #1 and option #2.

Efficiency units brand and model is one big consideration for the efficiency, (not to mentioned the brand and model that I am using currently) they are in the same rated capacity, different brand and model but not the same efficiency.

I would say if you can also give us the unit brand and model, probably one of our member can give you more detailed and useful recommendation especially if they are familiar on the said quoted unit, somebody could also probably tell you not to go for it due to this and due to that etc.

Kind regards

Roman

Thanks Roman. I will give the brand & model when i repor back to office.

best regards,

As a general rule, increase in number of engine units means increase in cost/kW. (when generators running at rated output).

Have you consider all the cost for 6 x 1.1MW option? (ex: cost for exhaust system, air intake system, pipe work, fuel system, transformer cost, civil works, etc). I feel 1^st option is more costly than medium voltage 3x2.2MW option. Further, maintenance cost will be greater, since more units mean more auxiliaries, more problems. Your building space will also be doubled in 6x1.1MW option.

6 transformers means, increase of transformer losses.

Are these 6 x 1.1MW diesel units running parallel? In that case your fault level on switchgear will be dramatically increase compare to medium voltage option, which will increase your switchgear cost.

The advantage I see (as mentioned in previous posts) 1) you will have more steps (1.1MW/2.2MW/3.3MW…6.6MW), so you may able to run the generators at optimum level according to the load; 2) Loss of one generator, will be loosing only 1.1MW of power, so you are in safer side than loosing 2.2MW.

Dear Sir,

What I feel is your both options are technically feasible but finacially weak.I have similar system what we have done is transfer all critcal drive to one bar with a bus section.During power failure your deisel set will start and open the Bus section and close the generator BkR and vice vera during power restoration . In this case you need only one set and the capacity to be defined by the actual load on the bar.But if all of your drives are critical then the option is not valid.In addtion to that you have not expalined about the process where the set is used and the partial failure does not financially effect your whole process.You can also calculate the ROI(Return on investment) how much it cost you during a failure and the installation cost.

Hi Dalton,

Cutting to the chase, you would not be asking about these if you did not need them, right?

Even though you may use them a few times per year, what you have to ask yourself is,

1) Can we do without them

2) Do I/we value the product or service highly enough to choose an expensive and reliable Model?

3) Do I/we think we may be able to get by on just a fraction of the power a particular Generator can provide?

I do not think you would be investing in a Generator if the answer to #2 and #3 was no. If the period of time over a year you use them is a few days or weeks but, you could not function without, then the cost of fuel has to be met whatever happens.

It is of no use to anyone to have what is effectively a fuel tank with a leak!

Which is what you would have if you got a potentially unreliable machine. And it depends entirely on what you 'do' as a company, whether you make or produce something to sell. Or perhaps you provide a service. Does this service and or product mean that if it is not there it will be life and death as in supplying energy to a hospital. Or is what you do so valuable to your company that there can be no break?

If the answer to this is no we cannot afford a break. Then go for the most expensive and well known 'Brand' you can. You may also be able to rent them from a company who provide servicing and or perhaps fuel? Just a thought.

Have you actually thought of whether it may be cheaper and more cost effective to produce your own power? Rather than buy it in from the 'grid' off Saudi?

I have always been accused, if that is the correct word, of being a show-off and 'thinking above my station' when I have bought things for reliability that were and are still expensive. But I am still using my 'expensive' items, while others have had to spend lots on Maintenance and or new items to replace a better built one! And, for the most part the cash others have spent trying to save money, actually exceeds what I paid just the once.

Good luck my friend.