Hybrid system for Sunreef 82 needed

A friend of mine is now about to order a Sunreef 82 catamaran, to be built in Gdansk, Poland. What he wants to change in the standard design, is a replacement for twin 330 hp diesel engines to provide low operation cost, clean, quiet and modern propulsion unit. Here is the preliminary specification of needs:

Sunreef 82 (http://www.sunreef-yachts.com/news,11,Sunreef-82.html) is a large cruising catamaran, with standard diesel propulsion of twin 320 hp engines. The future owner wants to replace traditional diesel system with a hybrid electric multisource system.
With the dry weight of around 82 tons, the yacht is expected to reach 10-12 knots of speed when motoring. The battery bank should allow to sail for at least 3-4 hours without starting a diesel. Diesel(s) would only be used for longer trips, in emergency situations and in case of lack of alternative charging power.
There are two charging sources expected (apart from the genset and shore grid connection) - three wind generators will be mounted in the aft plus a regeneration sailing mode for long passages.

I was searching this site, but all I found was either outdated or smaller than I think we need.
I am looking for some professionals whou would be able to deliver a solution and work with Sunreef to make it work. Any suggestion will be appreciated.
Peter

 

Any suggestion will be appreciated.

Review the many posts here , and break the news to the cash cow that its not yet practical.

As they would say in New Jersey "forgetaboutit".

FF

 

Hi Peter,

The first check regarding feasibility for hybrid electric drive is to compare the house and propulsion loads. In this case, propulsion power is a hair under 500 kW peak; if the house loads are of this order of magnitude or higher (say 100 kW plus) there *might* be an economic advantage to hybrid electric. (Indeed, it can be the case even in relatively small boats of 30-something feet that the house loads are greater than the propulsion demand, making hybrid electric drive a possibility)

Since I suspect that the house loads in this boat are much lower than the main propulsion requirements, a decision to use electric drive would have to be based on other criteria. Motoring with the engines off could be one reason. However, even with a big battery, you would not be able to do so for long in a boat of this size and weight.

The required battery bank will end up being heavy, expensive, or both. Regeneration via dragging the props is possible, but creates a lot of drag. The combination of heavy systems and dragging props will slow a sailboat down enough to frustrate its crew and guests.

If your friend is not concerned about the high capital cost, the increased operating costs, the weight and the reduced sailing performance, by all means feel free to try it. Steyr Motors makes a system that might be suitable for your application. If even that one is too small, you will likely have to turn to the commercial/industrial suppliers who do tugboats and small cruise ships.

If quiet motoring and low operating cost are the main criteria, it is likely that a pair of marine diesels, well installed in soundproofed engine rooms and equipped with top-quality mufflers, would be a satisfactory solution. But your friend wouldn't be able to say "it's an electric hybrid" when asked about it at the yacht club.... which might be the real reason behind this.

 

I looked into all this for my own vessel and this is just all a rough idea.
I'm sure someone who wants to sell you a system for $200,000 will pick this to pieces and say I'm wrong...but that's OK.

An engineer explained this to me once,and it's quite simple...
This is all just a rough estimate:

Like MM says what about house loads? and slightly under 500kw peak for the diesels but we don't know how much hp it needs to move at 11 knots...:?:


This is assuming you're running DC drives:
Lets just say you need 400 kw to move at speed,and use 120 VDC to cut down on losses.
Watts= amps x volts so 400,000=a x 120 .... so 3333 amps an hour using 120 volts.
I have a Lifeline agm batteries and they give 25 amps for 270 minutes to 100% discharge.
So if you need 3333 amps an hour: (3333/25) 140 of these at 50 kg = 7000 kg.
But you only want to discharge batts to 50%,so double that weight to 14,000 kg/30,000 pounds/15 tons.
At 500 kw....18,000 kg/40,000 pounds/20 tons.
Top quality lead modular 6 volt Surettes batteries +10% weight...500 kw =20,000 kg/44,000 pounds/22 tons.

Which I'm sure will slow the sailboat down so as to be useless and need to be completely redesigned anyways.
Either way he's be looking at ~$45k to $60k in batteries to be replaced every few years-hardly environmentally friendly.
Or he could just use the almost silent 350 hp 750 nm VW tdi at 460 kg/1000 pounds each and use 210 g/kw of diesel at cruise.
And with feathering props won't slow down your sailing speed.

http://www.vw-m.de/index.php?id=471&no_cache=1&L=1

If has the $6 million to build a new sailing cat,he won't care that it will likely be a net loss in money using DE.
He will likely use wind/solar etc to recharge the house batteries(or smaller gen set) and he may rarely fire the main generators.
So to spend the the same amount on diesel as it costs to replace the batteries seems maybe seems unlikely....

ps: as this is a very rough estimate anyone who wants to spend hours with a calculator looking up figures etc to refute me-go ahead-I won't waste my time debating you.

 

Well, I could pop out such a vessel at about 15 tonnes less weight to GL regulations.

But that is not the issue.

Quiet and modern is the issue.
Get a pair of Steyr or even Yanmars in and turn a big wheel.
And leave the "hybrid" nonsense.......

Nigel Calder is trying since about 15 years or so, and he is not a complete novice either, by so far with a clear result.

You cannot beat a good Diesel setup in ALL terms.

BTW
the given figures for propulsion would make a monohull of that weight fly at half throttle, so you should reconsider your designer / builder immediately!!!

Regards
Richard

 

Actually my weights are off...I was really tired and wrote it up fast

We need 400 kw @3333 amps/hour @ 120 volts

Having a 300 watt @25 amps/hr @ 12 volt 100 pound battery:

Step it up to 120 volts,wired in a series:so 10 batts in series= 3000 watts@25 amps @ 120 volts

Consider this to be one battery,wire up 30 of these in parallel...so 300 batteries (30,000 pounds or 15 tons) and u get:

Output: 90kw@ 750 amps/hr @ 120 volts @ 15 tons which is not nearly enough and not considering losses and inefficiencies..

Supposing he wants to cruise at 3 knots and use 10kw/100 amps(????) an hour he may run for 6 hours and go..not very far.
And has to charge 15 tons of ballast/battery on a cat that does poorly with weight.

Now,anyone considering battery electric drive can use these posts.

And to paraphrase Apex somewhere "we can end this foolishness"

 

Until the next time... I think we get a green electric boater/ free energy/wind mill powered idealist every couple of months.

On another related point, all these system in order to have a chance of working use high voltage AC based systems that drive inverters to vary electricity to motors to adjust speed. These are very, very expensive an not yet available in marinized small scale.

OH latest news.... Crew of Hybrid catamaran all fried when water leak in bilge reached high voltage wiring.....

 

Granted...I didn't feel like doing tons of research and calculations.

BTW a 200 kw continuous electric motor runs about 700-900 kg ~ a ton each...and are maybe $20k+ each.
And another2 dam heavy gen sets.

So add 2 tons of motor,maybe similar weight in generators onto the 15 tons of batteries to go maybe 25 to 30 miles....

 

Peter, I work for a company, ReGen Nautic, that has developed a hybrid system for yachts utilizing mostly off-the-shelf products from the transport industry with power range from 50 to 600 kws, that is ideally suited for your friend's Sunreef 82. You can have him contact me at info@regennautic.com.

There is a lot of misinformation in the market and a lot of failures and hype. ReGen Nautic strives to offer a solution that fits the application and needs of the customer. Technological advancements in energy storage and motor technology changes the landscape of hybrid offerings for yachts. We are seeing considerable efficiency gains on our prototype Grand Banks 42 with range increase from 600 miles for the boat equipped with twin Cat 3208's to 2,000+ miles with a hybrid system WITHOUT compromising top speed of 14+ kts!

There are many trade-offs when designing a hybrid system for yachts, including price, efficiency, space utilization, noise level, maintenance, fuel capacity, length of time at dock, maximum speed, cruising speed, parallel, serial or electric only, etc. Each customer has their own priorities, so an evaluation of whether hybrid technology is feasible depends on the priorities of the customer. Hybrid propulsion is available and it works for power and sail boats up to 600 kw per shaft.

 

That are bold lies! Nothing else!

 

apex1, I respect your right to your opinion, but it seems curious that you would make such an accusation with no data or information to back it up. We have hard, real-life numbers from actual, on-the-water testing to back up this claim. I will post them tonight or tomorrow and allow you to make your own determination.

I think it is important that these discussion boards remain productive and informative and will strive to only post relevant and factual information.

 

...OH GOODY I just got back from a fishing trip and I can't wait to see this.....

Like I said before,I'd buy it IF (so far no proof of anything by anyone) it worked and IF it made financial ( ie. not needing to circumnav 3 times to pay it off) sense.

Show me.

BTW looked at the UQM motors, 30 hp continuous and 133 lb ft.

Looking at a Kubota 60 hp,at about 1500 rpm we have 35 hp and 125 lb ft....so with a 95% (?) efficient 2.2:1 gearbox, at the prop we'd have about 270 lb ft.

 

Bold claims and lies............

excerpt from your site:

The leader?

ever heard of ZF, Volkswagen, Siemens???

They come for free?

And where are the news??? Is this new???



Bold claims and lies, as usual.

Now, prove me wrong Mr. ReGen!

 

You might get some attention if you post on youtube a video containing a non stop,no cuts video of:

-the engine room with all the electric drives with evidence of a Floscan ( or similar fuel flow meter) being hooked up to the gen set
-and showing a direct line to it's meter close to the engine room with
-side by side video of the Floscan and a GPS (or two) showing mph.

Also want to know if the batteries are "assisting" during this video.

 

It is unfortunate that this forum is hostile to hearing new data and information. ReGen will not enter into any hostile discussions based on unsubstantiated opinions.

We did commit to giving this forum real and actual data from our on-the-water testing, so here it is:

Our 1986 Grand Banks 42 has 600 gallon fuel capacity. There is considerable data on GB42s with twin Cat 3208 configuration consuming approximately 1 gallon of fuel per mile.

Our variable speed, common-rail, dc gen set generates more than 4.0 kw per liter (measured into battery). Last nights testing used less than 25 kw of power at the prop to move the boat at 7.0 knots. That is enough data to determine the range with the serial hybrid system of more than 2,000 miles.

We are happy to have discussions with interested people. We will be launching our system this year and have two installs scheduled in the next few months. Later this year, we will be doing demo rides for interested parties where anyone will be able to experience the benefits of electric propulsion and record any data they desire.