Propane-Powered Outboards by Lehr

Ever imagine boating without gasoline? No pain at the pump. Fewer dollars for despots. No ethanol troubles. And less emissions that add to the climate troubles. No, this is not a manifesto about paddling, rowing, or sailing. It’s about propane gas, which can fuel  internal combustion in sensible ways. At least that’s the idea Capt. Bernardo Herzer is putting before consumers, because he is convinced that a cleaner and more affordable energy future won’t happen without gaseous fuels.

The Lehr propane-powered outboards can run with a remote fuel tank or a screw-in one-pound camping bottle.

Herzer is a circumnavigator and a licensed captain, but more importantly, he’s the CEO of Lehr, a manufacturer of four-stroke propane-powered outboards that debuted at the Miami International Boat Show this year. These engines look and act much like the conventional outboards already familiar to boaters, and use a widely available fuel.

Lehr CEO Bernardo Herzer

“There are many upsides to propane-powered propulsion,” Herzer says, meaning in comparison to gasoline. It burns cleaner, it’s cheaper, it has high energy density, it’s readily available, and the US won’t have to import it from hostile regimes. And propane prices don’t skyrocket the way gasoline prices do. The average residential price for a gallon of propane was $2.87 in March 2012, a buck less than most people paid for a gallon of regular unleaded. The average wholesale propane price decreased by almost 8 cents per gallon to $1.24 per gallon, according to data by the US Energy Information Administration.

It took Herzer some time to get from the initial idea, inspired by the propane galley stove on a research ship, to the propane outboard. On the way, he took a detour developing and licensing this technology for lawn-care equipment, scooters, and go-carts. And he got Jay Leno to review some of these gadgets on TV. Today, Lehr holds numerous patents and was recognized with the EPA Clean Air Excellence Award and the Popular Mechanics Breakthrough Product Award.

Outboards that can run on compressed natural gas have been around for a while, but they failed to catch on, because fueling was a hassle, to say the least, and they weren’t all that efficient, simply because they were originally conceived for gasoline consumption. “[Our motor] is not a conversion of an engine that was designed to burn gasoline, but it was designed and optimized to burn propane, which is rated at 110 octane,” Herzer explains.

Lehr published research numbers that indicate propane produces 25 percent less CO2 and up to 60 percent less CO, while reducing the emission of ultra-fine particulates by 97 percent. According to the company, propane also has 96 percent fewer carcinogenic emissions than gasoline and zero ozone-depleting potential.

The 2.5-hp Lehr is shown here with a one-pound propane bottle as the fuel source. The company also makes a 5-hp model.

But it’s not all peaches. While there are many benefits to propane as a fuel, sourcing it as a byproduct of crude oil extraction remains ecologically problematic. As long as we are drilling for oil, we’ll get (relatively) cheap propane, which could power leaf blowers and outboards. At the same time it is a substitute for water in the controversial method of hydraulic fracturing (aka fracking) to get oil out of underground shale deposits.

But Herzer is focusing on the benefits downstream, which should be music to boat owners’ ears. Besides more benign emissions, propane-powered engines require less maintenance and fewer oil changes. “Ninety percent of the problems with gasoline outboards are related to either the carburetor or water in the fuel,” Herzer says before playing his trump card: “No ethanol.” Propane sidesteps the messy issue of the notorious fuel additive that helps gasoline engines burn cleaner, but absorbs water, making  it a formidable enemy of boat engines, fuel tanks, and lines. To combat these problems, boaters are required to treat their fuel with more additives, which adds cost and complexity.

Lastly, propane is easy to package in exchangeable tanks that are common for gas barbecues, or in 16-ounce cartridges that are screwed into the back of the outboard, the same as they would be in a camping stove or gas lamp. These receptacles are lighter than batteries or the thick-walled tanks that are needed for compressed natural gas, because propane liquefies at much lower pressure. According to Lehr, a gallon of propane can power a 5-hp outboard for up to two hours and the 2.5-hp model for up to four hours, depending on operator habits and sea state.

Lehr outboards are priced between comparable common four-stroke gasoline engines and zero-emission electric outboards. The 5-hp model sells for $1,920 (15-inch shaft) or $1,955.99 (20-inch shaft). The 2.5 hp comes with a 15-inch shaft only and retails for $1,200. The motors are offered with a three-year limited warranty and are sold by distributors such as Donovan’s and retailers such as West Marine. Lehr says more powerful models are in the pipeline.

Dieter Loibner