Co-gen Interconnection with local utility 1

[nightfox1925]

Hello sirs. I am involved in a feasibility project of constructing a bio-ethanol plant wherein the by product cane bagasse will be used to feed a boiler to drive a 3MW, 460VAC, 60Hz steam turbine generator. In order to improve system reliability and recover some costs, we are proposing to interconnect the said co-gen units to a 34.5kV local utility distribution via 34.5/0.46 transformers.

In this regard, I would like to request for any helpful web links that would provide better understanding on the prevailing requirements for an interconnection and how the export/import of power metering would be visualized. We are also going to coordinate with our local utility for their own requirements but some infomation of the same from other international counterparts would also be helpful.

best regards to all and thank you in advance.

GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata

 

[davidbeach]

You need to hire a consultant familiar with such installations. There are many things that need to be considered and this forum can not provide all the information needed to design this type of installation.

 

[richs]

Hiya-

PURELY for informational reading you might want to search on the internet for topics like "ship berthing" electrical and hospital standby generators.

3 MW might be a little high for typical shipboard phasing to commercial mains, but it is well within reasonable sizes for things like hospitals which should maintain an uninterruptable power supply to the facility.

As you bio shows that you are not a first timer to these boards (you've been here for awhile), I am assuming that you will be a participating (although maybe not prinicple) person in this project. I'm hoping that you are like the rest of us that would like additional information on a subject that we are tasked with. I would certianly agree with davidbeach in that I would be reluctant to tackle such a task for the first time all by myself.

Congratulations on your efforts to recover "waste" products into usefull energy. I, although a computer type, like every other engineering type, hates to see potential energy go to waste. In my state of California, I see lots of potential (gas flares from refineries, wasted head of water) not being utilized. Indeed, this very weekend, I was traveling in the central valley of our state and got to thinking (again) of agricultural wasted potential. We burn many of our fields after we have harvested our crops. It would be interesting to see if there could be a portable co-geneartor plant that is mobile that could transfer power to the electric grid from these field wastes. It most likely would not be profitable for one to collect the waste and burn them in a central location, but a plant that could travel along the fields to collect waste, generate and transfer at the same time. Think of a steam tractor with a *LONG* extension cord to the nearest power grid.

Anyway, best of luck.

Cheers,

Rich S.

 

[JBinCA]

I'm going to second DavidBeaches recommendation - Hire a consultant.

I recommend this if you're in the US more because every utility has their own requirements, interpretations of those requirements, and process for determining compliance with those requirements.

A thorough understanding of the control and protection concepts is certainly required to do this project, but is the knowlesge of the approvals requirements and process. It's probably cheaper to pay someone who already knows the latter than it is to learn it yourself.

I would actually differ with Rich S's two research recommendations. I've got a fair amount of experience with both shipboard and hospital generation projects and as a rule neither installation would operate a generator in parallel with the grid for any significant amount of time. Ships usually parallel and transfer very quickly from one source to another (the reason they tie to the grid is so that they can shut things down!). Hospital stand-by gens usually do not parallel at all - just open transition.

A recent thread touched on some of the issues surrounding continuous parallel operation, and yielded a helpful reference:

thread238-181861

If you go to this website,

http://www.woodward.com/pubs/pubpage.cfm

and type in 26260 and search all documents you'll get a reference manual called "Governing Fundamentals and Power Management". This is a very good manual and covers all that has been discussed plus a little more

Rich S. -

I live in CA's central valley, and we had one of the major co-ops of growers request a strikingly similar system to what you were thinking about. One of my colleagues ruled it out on a cost / benefits basis due to relatively low heat content of the typical retired plants and trimmings. The idea sort of died on the vine, if you'll excuse the irresistable pun there.

Renewed interest is being driven by a targetted 90% (if I remember corretcly) reduction in the allowable airborne particulate emmisions of the farms. The current solution to the waste is to burn it onsite, and that burning is in open air so it's not complete enough to come anywhere close to the emmisions targets.

Your vision may not be too far off, but I think collection and shippiing to centralized generation is more likely.

Regards,

JB

 

[nightfox1925]

Thank you gentlemen for your technical opinions. I am requesting for a meeting with the vendors and I will surely suggest to take the services of a consultant involved in this type of system.

GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata

 

[tinfoil]

At an absolute minimum, ask the utility where you wish to make the connection, as their rules are what count.

For example, in Ontario, where I work, the Provinccial Gov't has very specific guidelines to establish 'non-utility generation (NUG)'.

Look at

http://www.oeb.gov.on.ca/documents/cases/EB-2005-0447/appendixe_201206.pdf

and

http://www.oeb.gov.on.ca/documents/cases/EB-2005-0447/appendixf_201206.pdf

In addition, the local utility within Ontario may have some specific issues as well.

In your jurisdiction, the rules will likely be different.

Ask the utility.