Most Inspiring Proven Hybrid ?

Run that by me again.........

 

CAFE calculations don't work that way. A common misunderstanding, though someone claiming knowledge of the auto industry and issues with meeting future CAFE regulations should know better. CAFE calculations are based on consumption, not fuel economy. Consumption is the reciprocal of fuel economy.

An example of how the math works. How many 100 mpg vehicles need to be sold so that for every hundred 16 mph vehicles the fleet CAFE average is 25 mpg? Most folks would guess something like ten, and someone who remembers high school algebra would probably come up with an answer of twelve.

The answer is seven hundred and fifty 100 mpg vehicles would have to be sold for every hundred 16 mpg vehicles to achieve a fleet CAFE average is 25 mpg.

 

Here's how CAFE fleet average calculations work for a fleet with two vehicles:

CAFE fleet average = (combined sales volume of A and B) / {[(sales volume of Vehicle A) / (CAFE fuel economy number of vehicle A)] + [(sales volume of Vehicle B) / (CAFE fuel economy number of vehicle B)]}

It's sometimes refered to as a volume weighted harmonic average.

 

My apologies, upon further research it appears the foot in my mouth is a nice match for the boot applied to my ***.

 

Running Free, don't lose heart. I am designing hybrid drive into a new hull where batteries will constitute part of the ballast. My application is different from most - to generate from the shaft under sail and provide 1. Harbour maneouvering/getting out into the wind, and 2. Steady-state alternating from diesel to electric under long distance powered cruise.

My theory is that running the engine properly loaded charging and driving the shaft at the same time when underway by diesel will produce a combination of fuel efficiency gains, quiet periods, eliminate the need for a separate genset and allow charging via wind and solar during extended authoring.

My "stretch" dream is to attain up to 5 hours electric propulsion. Let the scoffers commence...!

 

"My "stretch" dream is to attain up to 5 hours electric propulsion."

Easy !!! if 1/2K is your speed of advance, calm water , no wind.

 

Har har

You are a very funny fellow. I'm surprised you didn't tell me to also look for a lake with a slope.

 

well fast fred has a point though - 5h of propulsion is very relative depending on size of a boat and the speed that is considered reasonable.
3knots in flat calm is quite a bit easier than 6knots in decent chop but for many 3 knots is not reasonable.

 

Aha - but without information on boat displacement, LWL, motor and battery sizes, these assumptions can't be made can they? My fault - I wasn't very corpus mentis yesterday because I was too doped up after surgery...

BOAT: Sailing Trawler, LWL about 53'
DISPLACEMENT: Don't know, maybe 50 US tons fitted out. Still a bare steel hull
POWER AVAILABLE: Experimenting, probably between 25 to 50 kW electric motors
driving the prop shaft via pulley
STORAGE: **** loads of batteries in the keel, which is a hollow steel keel big enough
for a man to climb down with steps to service the batteries

OK, so I've done the calculations, and I'm well aware that I would need a few tons of batteries to get 5 hours of electric drive at 5 knots with a max of 50% discharge. That may or may not be a problem depending on the budget. But I'm totally confident I can afford, install and maintain one hour's worth at perhaps 4 to 5 knots.

Having sailed over 22,000 miles aboard a 51' ketch, I have no illusions of cruising at hull speed in heavy conditions with electric drive and I have a 135 HP Perkins diesel engine to install too for that work. But I'm quite used to getting an efficient 100 miles per day.

If the best I can get is one hour on with the electric, then an hour with the diesel, then I'll be very happy to call it "Hybrid drive". The 48 volt DC motors are cheap and when under sail I will be charging for free off the prop shaft.

However, the biggest cost is the batteries! I'm open to any ideas on how to source the best approach. I've looked at various options such as Vanadium Flow and Nickel Hydride etc., sadly good old lead-acid seem the most cost effective. Maybe diesel-powered fuel cells might do it? I haven't had much luck finding reasonable flywheel storage. What's left?

BTW my calculations show that choosing the right prop dia and pitch under electric drive under calm conditions, I should be able to achieve 4.5 knots at 20 HP and 5.75 knots at 40 HP. Any whiz kids who could discuss this? Unfortunately I only have a diesel engine-based calculator, I don't understand how the different torque etc. changes it when using electric. For example, If I stick on a bigger diameter prop, will the electric motors happily accept it and get more speed? Or should I just get an Autoprop and let it handle the difference as it sees best for pitch? So many variables...

 

Hi Ray,
I assume you've been thru some of this material?
http://www.boatdesign.net/forums/boat-design/batteries-new-battery-technologies-21869.html

I've not been paying much attention to this subject for quite awhile. but I seem to remeber Profession Boatbuilder did an interesting article on real life battery tech that was just a grade above lead-acid, and was reasonably priced, and in operation now??

Perhaps check the links on the opening page?

Too bad that Glacier Bay had to give up on their prime developments
http://www.boatdesign.net/forums/boat-design/batteries-new-battery-technologies-21869.html#post193567

 

Solar power, batteries...

What is suddenly wrong with the fresh air? Can't have it greener and cleaner than the fresh air.

You know, the wind. The thing that propells sailing boats up to 50 knots per hour.

It's already here and it's been confirmed as the most efficient propulsion for boats.

Show me a battery or solar panel that can do that and create zero emission at the same time.

 

masrapido: "...wind. The thing that propells sailing boats up to 50 knots per hour."

Wow, that's quite an acceleration. In 4 hours that would be 200 knots!

 

Darn, and I thought that I'd confuse you if I write "90 km/h"...

 

50 knots per hour is actually 50 kts divided by hours which is 50 nautical miles .....

so the wind can propel a boat for 50 nautical miles ......

 

I was considering electric, as a package the technology is not sorted nor viable... Three mates have also tried it and all went back to normal options, (diesel saildrive, large outboard in a pod, sails and a pair of small outboards)... Electric systems do NOT CUT THE MUSTARD , , , YET?

Do something productive and use the search function and read all the relevant threads...