Marine gasoline and diesel engines are among the greatest contributors of hydrocarbons (HC) and oxides of nitrogen (NOx) pollution in the United States. In some regions, fuel from outboard motors is the primary cause of Federal impaired water body designations. Most boaters are aware that engine emissions can produce ground-level ozone and smog. Ozone is a recognized respiratory system irritant that causes lung and heart inflammation. Products of combustion include the greenhouse gases carbon dioxide (CO2) and carbon monoxide (CO). Carbon dioxide is seen as a major contributor to global warming.

Shifting environmental and economic concerns have generated the need for an outboard engine which is clean and cost effective to operate.  To combat hydrocarbon pollutants in outboard boating Stevens students designed a hybrid outboard motor with a dual drive arrangement consisting of both an electric motor and gasoline engine instead of the typical single power source.

Hybrid Outboard Reduces Emissions

Keith Haxton of the Hy-Board senior project design team reports, “Hy-Board is a hypbred outboard boat engine that reduces emissions based on a gasoline electric parallel drive.  It is fuel efficient  and environmentally friendly.  Hy-Board is significantly better than what’s on the market place.”

In this manner, the user may use direct electric drive while operating at low speeds and then engage gasoline drive when high speed performance is required. The flexibility allows the best features of each power system to be exploited to meet the customer objectives of increasing efficiency and reducing environmental impact.
 
Teammate John Pearlman comments, “The outboard motors on the market now are dirty-running. Our product eliminates the operating range in which the previous products are inefficient.  In other words, they produce less emission.”

The power sources are engaged by an unique constant variable transmission. This transmission uses variable sheaves actuated by axial cams to ensure that the maximum efficiency is obtained and no power is lost in transition. The product efficiently combines the benefits of both power sources safely and cheaply.

Driving a motorboat with an outboard engine for one hour may make as much air pollution as driving a car for 800 miles (1300 km).  Motorboat engines also pollute the water with their exhaust and by spilling oil and gasoline. Every year in the U.S., the total amount of water pollution from motorboats may equal 10 to 15 Exxon Valdez oil spill disasters. The chemicals in this pollution can kill fish eggs and other forms of water life.
 
Says team member Wayne Stankewicz, “ Whereas a gasoline motor produces high emissions, our hybrid electric motor achieves efficiencies as a dual power system.”
 
Boaters can make a remarkable difference in reducing marine engine pollution. Reducing engine emissions has a positive effect on diminishing respiratory conditions like asthma. The U.S. Environmental Protection Agency (EPA) is phasing in tighter emission standards for marine engines that are now coming on the market. High performance engines burn less fuel and lower pollution levels. The amount of fuel burned determines the carbon footprint of your boat. Reducing CO2 emissions lessens the production of greenhouse gases.

Engine Maintenance and Considerations

• Keep your engine in good condition and well tuned
• Follow the manufacturer's recommended service schedules
• Properly match engine horsepower to vessel size
• Install electronic engine and fuel monitoring equipment
• Avoid purchasing carburetor equipped engines

Use of these strategies will reduce engine emissions resulting in better air quality, reduced carbon loads and improved fuel economy.  In the meantime, keep your eye on the hybrid outboard engine market for Hy-board. The Hy-board is a new outboard engine concept in an attempt to satisfy the market demand.

Technology Commercialization

Although electric outboards provide excellent low speed performance and are becoming more popular, they remain unsuitable for high speed operation. Thus, there exists a market demand for a device that combines the excellent low speed efficiency of an electrically driven product with the high speed performance of a gasoline engine.

Says  Haxton ,  “At the same time we were designing our project, we took a course about technology commercialization.  We evaluated our project as a product that would go potentially out into the market.”  “We’re looking to pursue commercialization beyond school,” adds team member Michael Vitiello.  “The outcome will depend upon investment funding. Our idea has definite commercial application.”