While already converting as many buildings as possible to natural gas, the town is toying with the idea of switching some of its fleet to propane.
“We live in a country, in a world, where oil is expensive. Gasoline comes from oil,” said Selectman Andy Bodner, who passed a proposal from Rye Brook, N.Y., based Paraco Gas to convert some town vehicles on to First Selectman Rudy Marconi.
“We have abundant natural gas supplies,” Mr. Bodner continued. “As a matter of fact there’s a forecast that there’s a hundred years’ supply of natural gas in this country.”
“Natural gas” is different from propane, though the two are often used interchangeably. Natural gas is a naturally occurring mixture of gases that includes propane.
“More and more in Europe, Canada… large commercial fleets — buses, trucks, the vehicles” are run on these alternative fuels, Mr. Bodner said. “Hundreds and thousands of cars that work for utilities. The UPS trucks are moving to this cheaper, abundant fuel.”
Propane generally offers less fuel efficiency but can mean better performance than gasoline, since the propane has a higher octane rating. It also costs less per gallon and burns “cleaner” — releasing considerably less greenhouse gas.
Propane industry spokesmen say propane cuts greenhouse emissions over 20%. The Department of Energy reports that a study factoring in extraction and delivery methods, as well as how much carbon comes out of the tail pipe, put that figure at around 10%. Environmental Protection Agency standards require converted vehicles to have as good or better emissions, but the Department of Energy reports that an improperly done propane conversion can produce worse emissions than gasoline.
The make or break question is probably going to be: Can this idea it save the town money?
Paraco Gas belongs to a national network of companies that offer propane vehicle services, called Alliance AutoGas.
In an article in The New York Times, a North Carolina police department that used an Alliance company to convert to natural gas reported major savings on fuel — around 40% to 50%, according to the sheriff there.
There would be an upfront conversion cost — which the North Carolina department covered in part with money from drug seizures and a grant — to make the town’s cars or trucks run on propane, and possibly a conversion back to gasoline-only if the town wants to sell a vehicle. The conversion would be to a “bi-fuel” system, where the vehicles could still run on gasoline. It includes installing a separate tank, feeder lines and injectors, control hardware, and a dashboard switch to choose fuel type, according to Paraco Vice President Mike Gioffre.
It would also require a pumping station to be installed in town, which operates like a gasoline pump, which Paraco would install and maintain.
Conversion could be $5,500 per car, or more for some of the town’s larger trucks.
Buildings also have an upfront cost, but since the town tends to hang on to buildings longer than vehicles, building conversion can justify a longer “payback period.”
The town’s cost of gasoline is considerably lower than the average consumer pays at the pump — around $2.90 compared to about $4 per gallon in Ridgefield this week — the town doesn’t have to pay taxes on the fuel. Still, propane costs the town about $1.25 less per gallon.
What about safety? Isn’t propane highly explosive?
Yes it is, Ridgefield Assistant Fire Chief Kevin Tappe said, but all sorts of cars — gasoline, diesel, electric, even hydrogen — are on the road, and they each have their own safety challenges and systems to address those challenges.
Propane has been used to power vehicles for three decades, and both propane (called Liquid Petroleum Gas, or LPG) and natural gas (Liquid Natural Gas, or LNG) tanks are built to withstand serious abuse, Chief Tappe said.
“Since LPG and LNG are compressed gases, they must be stored in a cylindrical container that is tested and rated for the pressure involved. There are government or industry standards and regulations that pertain to the design, structure and breaking strength of the cylinders. In the many years that LPG and LNG powered vehicles have been in use, I cannot remember even one report in the country of an explosion, fire or other catastrophic release.
“There was one release in the Midwest a few years ago but it was the result of the LPG car being subject to a fire underneath the car. The pressure tanks for LPG and LNG are also built with relief valves that release excess pressure if the pressure should rise in the cylinder for some reason such as exposure to high heat.
Each fuel type presents its own challenges in emergencies.
“The flammable properties of gasoline, propane and natural gas are similar but propane and natural gas pose a more serious risk in that they are gases and expand as they are being released creating a flammable cloud of vapor that could ignite easily whereas gasoline, being a liquid, also gives off vapors but the liquid doesn’t disperse into the air but rather flows along the ground,” Chief Tappe said. “The flowing fuel makes it easier to predict where it is headed while a release of LNG or LPG is more difficult to predict. Both the vapors from gasoline and LPG are heavier than air and will seek low areas: Storm drains, basements, etc. LNG, on the other hand, is lighter than air and will dissipate in the breeze easier since it tends to rise.
The Fire Department has to prepare for other alternative fuel uses and electric and hybrid cars.
Hydrogen-powered cars are being tested by General Motors within 200 miles of White Plains, N.Y., so Assistant Chief Tappe attended a training seminar where some of the safety features were demonstrated.
“Hydrogen is the most flammable and explosive gas known to man — think the Hindenburg disaster…
“Of course, our main concern was the safety of the hydrogen cylinders, possible explosion or fire, etc. GM showed us the test results on the cylinders. They had shot at them with rifles, dropped them out of airplanes and run them over with tanks, and the cylinders did not fail.
Electric cars are another challenge, Mr. Tappe said. The high voltage systems are relatively simple to make safe if the car’s 12-volt battery can be accessed, but that is not always possible in a crash.
“We carry an entire booklet on our apparatus showing the location of high voltage batteries, 12 volt batteries and electric line placement for all makes and models of hybrid vehicles through 2012. Obviously, this reference material requires updating annually as new models are released.”