Follow-Up to https://www.eng-tips.com/viewthread.cfm?qid=461107 [ Floating Power Plants ] 1

[crshears]

Hello all,

Reading Bill's very sobering description of the virtually complete destruction of isolated power systems by hurricanes got me wondering...

Are there already ship-based power plants that tie up in disaster-struck places to provide temporary power until such time as new/replacement/repaired permanent infrastructure is in place? I'm not sure how to search on line for this information...my W/A/G is that such plants would likely have a total capacity of < 10 MVA, although I could of course be wrong about that.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[waross]

Hi CR.
As well as the generating plant, my customers on the island included two seafood processing plants.
Home was in the city of La Ceiba. A river cuts through the eastern part of the city.
Both bridges were out and I was on the wrong side of the river.
Sunday after the storm, the owner of one of the seafood plants knocked on my door.
He had found someone to take him across the river and found my home.
"Bill we need you, bad!
Don't go to the airline office in the city.
The flights are restricted and only emergency supplies are allowed on flights to Guanaja.
Go straight to the counter at the airport.
There will be an open ticket waiting for you and authorization to board the flight."

On Monday, one week after the storm had first hit, I was back on the island.
The plant owned a supply ship which delivered their product, mostly frozen lobsters, to the US.
Before the hurricane they had beached the ship and then flooded the ballast tanks.
It rode out the storm well.
The ship was tied alongside and a cable run into the plant. (60 KVA)
The cable was direct connected to one of the freezer compressors and every four hours they would shut down and change the connection to a different freezer.
First order of business;
Re-connect the cable.
Now we had lights and could select the running freezer by throwing breakers.
Further to your comments, CR, I was made aware of a floating power plant, but it was much too large to and was on the west coast.
The other seafood plant had two New Cat units brought down from Florida on their supply ship.
These units were in place long before the floating power plant could have been mobilized and rounded the Panama Canal.
But, yes, CR, shipboard generation is an option.

The human factor.
The working poor.
There are a lot of working poor, especially in the third world.
Most of us deposit our paychecks in the bank and then pay our living expenses out of the checking account.
The excess accumulates and is tapped for large expenses, cars, vacations, and for sivings and investments.
The working poor have no excess.
The day before payday, the bank account is empty and there is little money left in the pocket.
Then the disaster, be it hurricane, earthquake, flood or fire.
There is no more job and no more paycheck.
The end of the hurricane is just the start of the suffering.

The plant that brought me back had purchased two used generators but had not installed them.
They were purported to have been overhauled.
Actually they had had a Miami River overhaul.
That is a pressure wash and a coat of paint.
The first one on-line blew a rad hose after a few hours running.
The second had the wrong electronic governor installed and would not hold a stable speed.
One governor later, (mechanical, robbed from an unused engine) we got enough power back on the plant to go back to work.
About 50 working poor went back to work.
It was a good feeling.

The other plant a standby generator and started it up.
Unfortunately it was contaminated with sea water and lasted a few hours before the generator end disappeared in a cloud of smoke.
Somewhere here the other plant received the new sets and I took a day and got them back on-line.
Another 75 working poor went back to work.
Felt good but I didn't have time to sit around feeling good.

There was still the main plant to recover.
Out of time just now, but there were more adventures if anyone is interested.








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

 

[crshears]

Hello again Bill, absorbing account indeed...

Where my mind was going was to wonder if a smallish vessel [

http://www.scrutonmarine.com/p2421.htm

] with Diesel-electric drive could be converted to supply ~ 1 MW of power @ either 50 or 60 Hz, and if it could or would likely be put to good use; as per the link the vessel is currently for sale, and I suspect if the seller does not soon find a purchaser the vessel will be sold for scrap. [If that eventuality arrives, sad though the occasion might be I wouldn't mind being the "engineer" for the final voyage - I previously posted about my experiences aboard her].

Based on your experiences it seems highly probable that such a conversion would include installing as many fuel tanks as possible in way of providing extended run time...

Thoughts?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[zeusfaber]

It's not just power.

When a warship turns up at a disaster zone, one of the biggest benefits it brings (alongside well-equipped people trained to work as a team) is a chuffing great RO plant. Never mind the Air Force managing to fly in hundreds of bottles of fresh water, here's a facility that produces hundreds of tons of the stuff a day.

A.

 

[crshears]

Valid point...but political alliances may have a great deal to do with just whose warship will show up - or be invited - where...

Perhaps fitting in RO equipment as well should be tossed into the mental exercise...come it to that, what else?

Then again, perhaps it is unrealistic to expect every emergency support vessel to be all things to all needs; after all, not every privation will necessarily exist in every disaster zone...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[jraef]

After hurricane Katrina the issue of using US military vessels to provide shore power was looked at seriously. Large deck nuclear powered aircraft carriers can provide upward of 100MW if excess power. I don’t know the outcome of that study but I had a tiny tiny role in some of the minor logistics planning involved in building the rather substantial infrastructure necessary to facilitate it. My guess is that the entire issue was killed in terms of the funding it would take to build out that infrastructure with a low (at the time) likelihood that it would ever be be used. Has the increased climate risk changed that formula? I wonder. I’ve heard news stories saying that in the minds of military think tanks, climate change risks have moved closer to the top of the scenarios they think about.

For sure, the issue of naval vessels providing a mobile water supply, food relief, medical relief and fire fighting force is and has been provided as a form of humanitarian aid, but connecting electrical power is not in the least bit as simple as it sounds on the surface.

As I recall from my minor involvement, the only story they shared as an example was one where a naval ship temporarily powered a set of locks on the Panama Canal when the local power plant went down. The required infrastructure it took to pull that off was used as the example to be followed.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[crshears]

My thought was that for relatively small amounts of power, a vessel could be secured alongside a pier or wharf closest to the shore [so as to not have live power lines running right where other vessels would want to discharge their cargoes], the vessel's aggregate output being brought up via cables to potheads, thence via overhead span to a single shore feeder. PTs and CTs would provide intelligence to an onboard programmable feeder relaying scheme, tripping off line any running generators, etc., etc.

The issue of matching supply voltages, phasing and frequency would of course require careful attention.

One issue I could foresee is providing a temporary and portable means of conducting the warm engine discharge water far enough away from the vessel so as to mitigate recirculation concerns and avoid rejecting more heat into a confined body of water, such as a harbour, than it will naturally dissipate.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[waross]

You're overthinking it. CR
In our case, they ran a cable across the dock and tied directly into the control panel for a freezer.
Nothing fancy.
I moved the connection to a JB that would back-feed into the main panel and let us choose loads by switching breakers.
When we got both the used generator running, instead of trying to parallel, we dedicated one gen-set to the ice machine and connected the other gen-set to the main panel.
A disaster is hard to plan for.
It was a case of what is the most pressing need?
What resources do we have?
Can we meet the need with what's available?
Some needs can not be met.

Heat rejection:
This was a seafaring community and while I was the authority on things electrical I was not always involved with things mechanical. (Unless the local fix went completely sideways.)
Some of our radiators needed replacement.
Rather than new radiators, the powers that be installed a heat exchanger and built a keel cooler to cool the other side of the exchanger.
The keel cooler (A grid of parallel steel pipes) was dropped into the sea a few yards off shore.
I found software to calculate keel coolers.
According to the software, we needed to get the power plant up to 10 knots!
But the software did not take into account a couple of hundred feet of pipe buried in damp sand.
That made the difference and the system worked fine.
This was for either one or two 600 KW sets. Memory fails.


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

 

[waross]

Thanks, CR, for giving me a chance to share memories.
I should declare a standing anecdote alert for this thread.

When a warship turns up at a disaster zone, one of the biggest benefits it brings

Some thing that I have not seen in any newspaper accounts nor online searches.
There was a large British Warship in the Gulf of Mexico shadowing and dodging the hurricane.
It anchored off the island of Guanaja and the sailors went ashore to provide emergency aid.
It looked like a small city sitting offshore.
As far as I know, the captain reacted to the situation and rendered immediate aid, with bothering with diplomatic niceties.
Shortly after I arrived it left.
I did not see any sailors but talked to many local folk who much appreciated the emergency help.
I was told that the sailors made sure that any needed medical help was provided and also cleared the walkways of fallen power poles and cables.
Then they "Got Out of Dodge" as it were, before sparking an international incident.
Kudos to the Captain for throwing out the rule book when humanitarian assistance was needed.
Zeusfaber, do you have any military/naval contacts who may be willing to shed some light on this?


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

 

[crshears]

waross stated: You're overthinking it, CR. In our case, they ran a cable across the dock and tied directly into the control panel for a freezer.

Hi Bill,

I agree that in the instance you're citing I'd have been overthinking it...

However! I'm citing a plant of ~ 1 MW, and running a cable across the dock to a freezer unit might not be the best way to go in a case like that, and I think it very definitely would not in the case of where a "large deck nuclear powered aircraft carrier" is looking to "provide upward of 100MW of power" ashore; straightforward scaling up and down could cause some problems...so in my view the degree of thinking involved is greatly impacted by the order of magnitude of the scenario in view.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[zeusfaber]

Bill,
It happens a bit like that all the time. The RN keeps at least one unit in the Caribbean throughout the hurricane season in the expectation that it will be needed somewhere. As long as the sailors behave themselves and the ship doesn't outstay its welcome, there's unlikely to be much diplomatic trouble.
A.

 

[jraef]

Sailors behaving themselves... riiiiiight.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[waross]

Thanks zeusfaber.
CR. It depends on the scale of the disaster.
When Japan lost the nuclear plant, a large ship feeding the grid would have been a quick and effective solution.
For other disasters, it depends.
If national disaster planners start thinking that way, I imagine that there will be stockpiles of equipment potted in coastal areas to facilitate the connection of shipboard power.
Pick a spot on the coast on your network where there is moorage for a large vessel.
How close to the shore is the nearest distribution circuit?
What is the capacity of the transformer feeding that circuit?
You can't put much more than the circuit transformer capacity back into the grid.
Yes you can overload the transformer drastically but you can't push 100 MW through a 10 MW transformer.
For dedicated loads such as a hospital there may be other solutions.
Caterpillar has built a lot of plants in semi-trailers.
Capacity around 1 MW to 2 MW.
These units have synchronizing gear and transformers.
Pull in and park, connect three or for overhead cables and hit the switch.

Where do you get them?
Probably a mine site that's off the grid.
Which is more important?
Critical services in the center of a disaster area or a mine site.
It depends.

Years ago a severe storm took down a couple of transmission towers on a 500 kV line feeding Vancouver Canada.
The cross-arms were salvaged from the downed towers and lifted with large mobile cranes.
Service was quickly restored.
Something similar could be used to run lines from a ship to the point of connection.
Three or four spans per mile for short distances.
It depends.

A normal back-up system will carry through a normal outage.
In the case of an rare abnormal outage where a system that was counted upon in the planning is also taken out, or for some reason is not available, you do what you can with what you have on hand.
I don't Canada has anything like FEMA.
That may be an advantage.
Good discussion.
Different points of view.
When the big one hits, the solutions may be something that we have not anticipated.


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

 

[waross]

Sailors behaving themselves... riiiiiight.

This wasn't shore leave.
This was work parties.
When I arrived the ship was standing off but no sailors were on shore.
I did not hear one account of colorful behavior.
They came onshore to work.
They worked.
They left.


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

 

[safspir]

Well worth repeating. Thank You Bill. "When the big one hits, the solutions may be something that we have not anticipated."