1. Alternative Energy Propulsion in Short Route Ferries
Case Study: Halifax Harbour Ferries
Presented By:
E.Y.E. Marine Consultants
Good morning everyone and welcome to E.Y.E. Marine Consultants presentation On Alternative Energy in Short Route Ferries
We chose this topic a while back and it seems a perfect fit for this conference and its focus on the environment and the restriction we will soon face.
For our presentation we will look at one of E.Y.E’s most prolific designs and one I’m sure you are all familiar with by now; The halfax Dartmouth ferry and route. (Click)

2. What is meant by “Alternative Energy”?
Hybrid
Green Energy
-So what is meant by Alternative energy?
-Every generation seems to have certain catch phrases that stick out.
-Certainly these days Hybrid (click) is one of them along with others such as green energy (cliclk)
(Click click)
These phrases are usually used in on there own or in conjunction but there are almost always used when trying to (click) Reduce Emissions
But (click) Does it Pay to do us green energy or alternative energy methods?
Shipping industry has always been considered a dirty industry; you just have to go down to the harbor front and you’ll probably see at least one or two ships belching out smoke out of there exhaust pipes
As an industry we need to work harder to develop alternatives that help to reduce emissions and provide something better for the future generations as many of our pervious presenters have stated. (Click)
Reducing Emissions
But Does it Pay?

3. What we Are Comparing? vs. vs. Diesel Propulsion Battery Hybrid
Battery Powered
Main source of power from Battery Bank
No secondary sources of power
Plug into electrical grid during stops and over night
Diesel Electric
Main source of power from Battery Bank
Secondary sources of power from diesel generator
Plug into electrical grid during stops and over night
Diesel Engines
Main source of power from diesel fuel
No secondary sources of power
So what are we comparing?
We will compare the existing diesel propulsion drive solution to a hybrid drive solution and also look at if a totally battery powered solution is feasible today. (Refer to slides)
click

4. Energy Density
-When looking at alternative energies the best variable to look at as ship designers is energy density.
-Energy density shows us how much energy there is in a given technolgy versus its size and mass (click)
-So we here the energy density of 1 liter of diesel fuel, approx kWh per litre
-Then we have probably the most advanced batteries today Li-Ion (click) at 163 Wh
-And then our premium Lead acid AGM batteries (click) at 20 wh per lire
-you can see the considerable decrease in energy
-This is why batteries are only suitable in short route ferries at present. Batteries would be too large for long route applications.
(click)
-Even when you factor in the approximately 40% effeciney of a diesel engine to generate electrical power diesel still overwhelming favourite. But it is this 60% loss in energy that we want to exploit. (click)

5. So Why bother? Total Savings of $503.30/day
Consider ferry uses 15L/Trip of fuel
Ferry operates 67 trips a day
That’s 1005 Litres of Diesel Fuel per day.
@ $1/L that’s $1005/day
Total Savings of $503.30/day
Amount of energy used per day
1005L x 10.4 kW-h/L = kW-h/Day
Diesel engine operates at approximately 40% efficiency = x .4 = kW-h/Day
Average rate of power from NS power is $0.12/kW-h
Total operating cost = x 0.12 = $501.70
So why such poor energy densities why bother even looking at batteries in our propulsion systems. (Click)
-Refer to slide
(next slide)

6. Let’s look at Batteries
Lead Acid
(AGM)
Lithium Ion
Nominal Voltage
2.0V
3.70V
Energy Density
20 Wh/kg
163 Wh/kg
Cycle Life
(50% DOD)
~3000
(8 yrs.)
~300,000
Charge Capacity
C/5 2C
Pack Maintenance
$0/ Life time
Installation
Cost
$20 /kW-h
$1600 /kW-h
Recyclable
Yes
-So there is an advantage so let’s look closer at batteries for a minute
-For the sake of this study we will compare the standard Lead Acid type AGM with the latest in battery technology, Li-Ion
Li-Ion is consider probably the leading technology in batteries today
And AGM are the best of the lead acid batteries that are the standard for most commercial applications for the past several years.
Nominal voltage; higher voltage means less cells required in the bank bank
Energy density as we saw in the last slide
Cycle life; No battery likes to be discharged completely. This reduces the life of the battery considerably. So if we look at the cycle life if we discharge the batteries to 50% their capacity we see the AGM will last approx. 8 years before needing to be replaced while the li-ion will essentially last the life of the ship.
I was told by many battery manufacturers that once installed both types of batteries will require zero maintainence over the life of the battery.
Now a big one; the cost to install. Ouch the li-ion is very expensive.
Finally both batteries can be recycled, which is good as it would not make sense to use batteries to help the environment only to fill our landfills with toxic chemicals once they are used.

7. Battery Propulsion Total Required Capacity: Diesel = 10451 kW-h
If we look at the rate of power consumption for both diesel and battery power.
Very large difference.
Note; How battery capacity curve flattens between trip 21 and 31 and again at 56 onward. This is due to moving from 15 min sch to 30 min sch with twice the recharge time.
Total Required Capacity:
Diesel = kW-h
Battery = 2626 kW-h

8. The Breakdown Total Power Used = 4238 kW-h/Day
Total Rechargeable Power = 1620 kW-h/Day
Available Regeneration Rate
600V x 250Amps = 150 kW
Off Hours Recharge required = 2625 kW-h/Day
Total power consumption comes from maximum power draw from appropiate sized DC motor.
The maximum charge rate Transport Canada will allow in TP127E is 250amps
If we use a normally obtainable high voltage of 600V
Our regeneration rate becomes 150 kw
Therefore our off duty recharge will be 2625 Kw-h/day

9. The Good This gives us a savings over the diesel propulsion of
Emissions factor in NS powers CO2 emission approx. 899 g/kwh

10. The Bad Actual Battery Capacity Needed: AGM = 6562.5 kW-h
Li-Ion = 4375 kW-h
Installation Cost:
AGM = $ 131, $20/kW-h every 8 years)
Li-Ion = $ 7,000, $1600/kW-h Life time)
-As stated before All batteries do not like to be discharged fully all the time.
-To get the maximum life out of a battery
-AGM’s cannot discharge below 40% of full charge and Li-Ion not below %60.
-This adds to the required capacity install onboard and the installation costs.
-Yikes, that is a large initial capital cost
Then factor in the installation cost and you see especially with the Li-Ion the cost is huge!

11. Over 30 yrs.
If we look at a very basic 30 yr life cycle cost you can see that AGM’s look pretty good while the Li-Ion battery bank is very expensive relative to diesel power.

12. The Ugly Actual Battery Size Needed: AGM = 321,125 kg or 87.5 m^3
Li-Ion = 26,840 kg or 13.7 m^3
Now the ugly;
Remember the energy density and how much lower the AGM and LI-ion were?
Current ferries have full load displacement of approx. 200 tons. Therefore AGM not sensible solution.

13. The Ugly Cont’d Charging Constraints: 600V x 250 Amps = 150 kW
Max. Charge Off Duty
150 kW x 6 Hours x 2 chargers = 1800 kW-h
We Require kW-h
-If we cannot recharge at more than 150 kW
-And We are off duty for 6 hours, therefore our maximum charge capacity is 900 KWh
-If we assume there are two battery banks each with a charger than we get 1800 kWh 13

14. Now Where? What are the things we need to change?
Need to reduce the Battery Bank Size.
Reduce the Battery Bank Capacity.
Reduce the installation costs for the battery bank.
So now where?
Well, we need to work at reducing the battery bank size
We need to work at reducing battery capacity, which in turn reduces the size of the bank
We need to reduce the cost to install the battery bank
See the trend here?

15. SOLUTION?
HYBRID!
So what is the solution
Hybrid or Diesel electric

16. Hybrid Propulsion
So with a hybrid system we look at installing 1,2,3… generators to help continually charge the battery bank.
Hope is to run ferry off batteries and save fuel by only using a smaller generator to help suppliment power.
But How many generators do we need??
If we Base on our calculations on a 44W genset, you’ll see why we choose this size of generator later.
The more generators we add the smaller the required battery bank gets. Great!
But there comes a point when we start to get more generated power than we really need.
This defeats the purpose of having a battery at all as we are burning diesel fuel to generate this power.
In this case the best solutions look like either one or two generators.

17. The Breakdown 1 Generator: Required Battery Capacity = 1660 kW-h
Installed Capacity:
AGM = 4150 kW-h
Li-Ion = 2667 kW-h
2 Generators:
Required Battery Capacity = 1000 kW-h
1660 under the 1800 kW-h overnight charge threshold. This is why we choose the 44W generator size to achieve the maximum overnight charging rate, or as close as we could get.
You can see as significant drop in installed capacity versus the pure battery solution.
Installed Capacity:
AGM = 2500 kW-h
Li-Ion = 1667 kW-h

18. 30 Year Cost Comparison 1 Generator 2 Generators
If we look at our basic 30 yr life cycle costsing and
Factor in Engine costs, Additional fuel costs, and Maintenance costs We see that there is a slight savings using one generator for both AGM and Li-Ion and with 2 generators just the AGM solution makes sense.
Or does it???

19. The Physical Restrictions
Actual Battery Size Needed:
AGM = 207,500 kg or 53.3 m^3
Li-Ion = 16,973 kg or 8.7 m^3
Li-Ion Only Solution
Again we have to go back to the poor energy density of batteries and we see that the AGM solution still does not make sense.
But
Li-Ion looking not too bad

20. The Good and Bad The Good The Bad 30 yr. Savings of $ 790,458.40
Emission Savings of CO2 = Tons/yr Nox = 5.96 Tons/yr
Less exposed to fluctuations in fuel prices
More exposed to fluctuations in electricity prices.
Still very high installation Costs
Additional costs for charging infrastructure required at dockside.
So here are the good and bad to our hybrid solution using 1 generator and Li-Ion batteries.
Good
Significant savings over 30 yrs operating appr0x 6.5%
Large savings in emissions
Have less exposure to oil price fluctuations
The bad
More exposure to high electricity prices
Still very high relative installation costs
Have added expense of charging infrastructure dockside

21. From Here? Further analysis required into ferry operating loads.
Further study into optimal generator size and quantity.
Discuss possible safety issues with regard to stored battery capacity.
Look for better battery technology to improve energy densities.
Determine Charging infrastructure requirement and cost at dockside.
Collect firm data with regards to purchasing bulk energy and off peak recharging.
1) Further study into ferry operating load; to further try and reduce battery capacity (for this study we looked at full power loads)
2) Further study into matching generator size and quantity to maximise the battery usage, longevity and recharge cycles
3) Discuss with Transport Canada minimum tolerance with regard to generating power and battery capacity during the operation of the ferry.

22. Conclusion Technology is viable today with modest savings.
Further savings possible with development of emission credits.
Government incentives to promote and off set large installation costs.
Further reduction in price with bulk purchases of power and off peak recharging.
Satisfaction of saving emissions and helping environment.

23. For a copy of this presentation please visit our latest news section at our website:
E.Y.E. Marine Consultants Suite 1, 327 Prince Albert Road Dartmouth, Nova Scotia, Canada B2Y 1N7 Phone: (902) Fax: (902)