1. MARINE ELECTRIC PROPULSION Rethinking Energy, Motion, Space, & Time On Your Boat

2. Perfect Propulsion System Manufacturer would pay you Infinite speed No pollution; it removes pollutants wherever it goes Cures athlete’s foot, ED & psoriasis End wars, turns debts into surpluses Sorry, Can’t Do… But Can We Improve Boat Propulsion With 21 st Century Tech? YES!

3. Back to Basics: Getting A Boat Moving Push Through the Water… Displacement Skim On Top… Planing

4. Today’s Focus: Displacement Planing Hulls? Some Other Time. WHAT WE NEED – A JET OF WATER MOVING AFT

5. Another Way…Jet Engines!!

6. Seriously…What Propellers Do GRAB THE WATER, PUSH IT AFT

7. How Propellers Do It? FEED THEM TORQUE

8. Isn’t This Presentation About Electric Propulsion? WHERE ARE THE AMPS & VOLTS? Not Yet…Soon

9. Prop Properties To Push More Water More Blades Larger Diameter More Blade Angle (Pitch) Spin Faster To Push Less Water Fewer Blades Smaller Diameter Less Pitch Spin Slower Props Don’t Care What (or who) Is Turning Them

10. Boat Properties I Less Power to push Longer waterline length Less weight Less beam Fin keel Less Speed Boats Don’t Care What Is Turning Their Props

11. Boat Properties II More Power to push Shorter waterline length More weight More beam Full Keel More Speed Boats Don’t Care Who Is Turning Their Props

12. What You Use To Turn The Prop Shaft Is Secondary; Your Boat’s Design, Weight & Speed Drive The “Power Equation”

13. Even If You Have These Guys…

14. What A Prop Really Wants From 0 to 1 knot Prop has to overcome inertia of still water Must establish moving jet, but it need not be fast Needs lots of torque to do it RPM change is small Consider a Displacement Hull Vessel With a Maximum Operating Speed of 6 Knots Under Power

15. What A Prop Really Wants From 5 to 6 knots Inertia is not an issue; water jet is already moving Prop must accelerate the moving water jet Torque increment is small RPM change is huge Consider a Displacement Hull Vessel With a Maximum Operating Speed of 6 Knots Under Power

16. Props Want High Torque @ Low RPM, High Speed @ High RPM… …Which Is What Electric Provides

17. Now Consider A Diesel Engine Low Torque @ Low RPM Torque Catches Up @ High RPM Must be OVERSIZED to address mismatch This is why so little happens in the first third of your throttle’s arc of travel

18. Knock-On Effects Of Oversized Diesel Engines In Sailboats When diesels perform best: – At full design temperature, which means… – At or near full throttle most of the time On sailboats, they run intermittently at various throttle settings – “Wet Stacking” – Incomplete fuel combustion – More maintenance, shorter life Not easy to “fine tune” prop thrust

19. Deeply Conflicted Diesels Propulsion is not the diesel’s only job It also has to spin its alternator for battery charging Easy in the old days…not much power needed Today…different story

20. “What Is My Purpose In Life?” Propulsion or Power Generation? Do you run your diesel in neutral to charge your batteries? Let’s use a 27 hp diesel as an example…it’s equivalent to about 20 kW (before losses) You upgraded to a 200 amp alternator Call it 14 volts – that’s 2.8 kW max Diesel is grossly under-loaded! …Your diesel engine keeps asking itself

21. Recap – Diesel Issues on Sailboats Mismatch in torque curve → oversized diesels Mismatch in usage for long, trouble-free life – Diesel likes to run hot most of the time – Sailboat needs intermittent use, often at low load Conflict: Diesel is asked to push the boat and make electricity too – totally different uses

22. …While Introducing No New Ones, Right? Electric Propulsion Solves All Of These Problems….

23. We Wish. Electric DOES Offer: A streamlined way to organize energy generation, storage and use A highly modular approach – easy to mix and match components at various price and performance levels A set of trade-offs that make it right for some and not for others

24. With Electric, Propulsion Is Just Another Load Energy Sources Dockside Power On-Board generator Solar Panels Wind generators Fuel Cells Regeneration under sail Energy Storage Lead-Acid Batteries – Golf Cart – AGM’s – Thin Plate Pure Lead AGM Lithium Ion – LiFePo4 – LiMn NiFe Energy Users (Loads) Propulsion Motor Fridge Air Conditioning Windlass Nav & Comm Instruments Lights & Fans Pumps TV, PC, Tablets

25. …So Treat It Like Any Other Load How much power does it need? For how long? Always at max power when it’s on? Probably not, most of the time Add its load to all the others Compare with energy storage capacity Factor in contributions from sources Size the storage and the sources such that the storage always has a reserve

26. …Just Like They Do In: Cruise & Navy Ships Subs Diesel Locomotives In fact, small craft, with their diesel engine- transmission drives, are the outliers

27. Wait A Minute… Some of the sources are AC, others DC Some of the loads are AC, others DC Now add electric propulsion… it’s 48 Volts DC, 72, 96 or more Can’t mix and match, Right?

28. Actually… AC to DC: rectification DC to AC: inversion DC voltage to a different voltage: conversion All of these are easier, better, cheaper today: – Many manufacturers and products to choose from – Off-the-shelf, proven technology, mass-produced components, reliable, efficient, affordable

29. So… You can focus on: – Energy coming in – Energy stored – Energy going out Let geeks like me worry about: – AC-DC & DC-AC transformations – DC-DC voltage matching – Controls – Monitoring & Display

30. The Result Daysailers (no generator): – Go out any time; no winterizing in cold regions – No outboard or diesel engine maintenance – Quiet, precise control, easier handling Cruisers (with generator) – Much more effective use of diesel engine; low- load operation nearly eliminated – With DC-DC converter, one generator charges both propulsion batteries & house batteries – Quiet (when gen’s off), precise control, etc.

31. RECAP Thanks to recent technology advances, small craft can feasibly be powered electrically, like large vessels and locomotives, with lots of benefits and some drawbacks. For many boats and owners, the case for electric is compelling.

32. FOR MORE INFO www.annapolishybridmarine.com ddiquinzio@annapolishybridmarine.com David M. DiQuinzio PE 443 924 4484 THIS PRESENTATION CAN BE VIEWED AT www.annapolishybridmarine.com/ marine-electric-propulsion-presentation.php