Mercury Marine Diesel Electric Hybrid Concept Vessel

I Have Seen The Future!

Dressed in eyecatching graphics, Mercury’s Hybrid Concept Vessel was a Miami International Boat Show highlight last February – but a quiet one. Equipped with both Cummins QSC 550, 550-hp diesel engines and Zeus pod drives plus high-efficiency electric engines, solar panels, full SmartCraft controls including joystick docking, the Mercury’s Hybrid Concept Vessel glided out of its slip like it was drifting in the wind, making virtually no sound, no smoke and no smell.

Yet, the driver of the boat simply used the Zeus joystick control to pivot in the channel and head out the harbour gap under electric power, even through stiff winds. The only sound was from the turbulent water at the transom.

As much as I care about the environment, the idea of an electric boat or a hybrid diesel electric boat had never really caught my attention simply because I didn’t see this as being mainstream. Of course, many Canadian Yachting readers would applaud the environmental effort, but I had no expectation that a hybrid yacht would be a realistic alternative to regular power systems.

Then I went out on the Mercury Marine Hybrid Concept Vessel.

Able to run on just electric, just diesel, or a combination of both, the captain can choose the best mode for the conditions. Out on the water, the transition from one mode to another was almost imperceptible except for the sound of the diesel engine (or the lack of it).

Cruising under diesel power, the electric engines can be used to recharge the lithium-ion battery banks that power the boat’s two 100-hp electric engine/generators. You can also plug it into shore power or re-charge with the array of solar panels fitted on the deck and hardtop. The Hybrid Concept Vessel is an amazing showcase of new technology, but the most important fact was that it all worked so well in a conventional 42-foot express coupe yacht.

Probably most important to prospective buyers is the appearance. Well, this is a conventional but handsome express hardtop cruiser – nothing weird or radical. You would never know that it was a hybrid boat from the appearance (or the performance) and the penalties in weight or increased cost are projected to be well within the envelope of what buyers are comfortable with. This boat is more than just a dream boat.

Dan Balogh headed the development team at Mercury and he explained to me that using the lithium ion batteries that have high power density, but much lighter weight than lead acid batteries, there was a mere 2,000 lb. of additional weight on a yacht that was 35,000 lb. to begin with. That’s a small price to pay in weight.

Speaking of the price, the “buzz-kill” question is always, what does this cost compared to a conventional solution? David Foulkes, Mercury’s VP of Product Development and Engineering said he anticipated a 7 to 10% cost premium – that was all.

This is partly because there are offsetting savings. The battery banks are a lot of money but so is a diesel generator. The battery bank in the Mercury Hybrid can power the yacht for 2 to 3 days without recharging, so you can save the generator investment and its significant weight as well. Consider this: peaceful sleep when cruising without noise or vibration from a generator. Run the A/C all night from the 300-volt battery bank. It has 60 kWh storage and the batteries are in a waterproof compartment.

The solar panels on the hardtop are always charging in daylight and they feature integrated bi-facial panels. So, they capture direct sunlight and reflected sunlight from water. Next, a clever four-panel solar array folds out on the forward deck when you are moored. That adds a lot of charging power. In a week of sitting, these can fully recharge the batteries at no cost.

Befitting a concept boat, there were also additional safety features such as a theft deterrence system and on-board monitoring systems using telematics, (similar to automotive systems) so the boat can be “watched” remotely. Another safety addition are the transom lights that communicate to other boaters and swimmers that the boat is “on” and propellers may be spinning – critical information when you remove the sound of the engines by running on electric power. Finally, the solar power is independent of shore power and provides electrical backup to bilge pumps, starting batteries and other critical components. All very handy!

In fact, although the Mercury Marine Hybrid Concept Vessel only reaches 8 to 10 mph running on electric power alone, it means you should never be stranded. Hybrid propulsion combines reliable diesel engines and electrical systems providing built-in backups.

The electric motors both contribute 100 hp and also act as big generators when the CMD QSC 550 Zeus diesels are running. They boost charging capacity in a big way when the yacht is on plane and cruising.

We say it that way because the twin 550-hp diesels are plenty of power once the yacht is up and running but they are sized small for planing off a load. No worries. The electric motors can clutch in to add a big boost in acceleration. With both the QSM 550s and the electric motors engaged, this yacht leaped onto the plane in just 6 seconds!

The Mercury engineers said that the combination of high-torque electric motors with high-output diesel engines gets the boat on plane twice as fast as conventional power. As soon as cruising speed was reached, the motors can begin working as generators to recharge the batteries.

The photos show how the electric motors are easily integrated into the CMD Zeus engine and drive systems and the Hybrid Concept boat had a nice big engine hatch for easy service and also to show off the engineering. You could really live with this rig and you would have an easy time of it because the boat had the Mercury SmartCraft instruments, throttles and Joystick control systems. These are intuitive controls that make the entire boat easier to use.

It has automatic electrical power switching between vessel power and shore power meaning that the system is ready when you are. Just “unplug” from the shore power and go. A helm-mounted large-screen display keeps the driver informed of system status. Fuel levels, the state of the batteries’ charge and far more, is displayed.

Like other regular Zeus pod drive systems, this has all the bells and whistles such as the autopilot and “Skyhook” functions.

Skyhook is a GPS-controlled station-keeping function that uses the pod drives to hold a steady position for docking, fishing and those times like waiting your turn at a bridge or fuel dock. In Skyhook, you can run the CMD diesels but you can also use just electric.

This eliminates fuel waste, exhaust and smoke as you stay stationary.

Electric is also the economical and environmental way to enjoy relaxing rides down intracoastal waterways, rivers and through speed restricted zones.

Considering all the added functionality and the long-term fuel savings that are potentially available, silent nights on the hook plus, the propulsion redundancy for safety, I think many buyers would feel the added weight and 7 to 10% additional cost was money well spent.

I hope more people have a chance to both see and actually drive this boat, then they too will feel they’ve seen the future!

By Andy Adams