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Created page with "= Fuel Cells = There are several [ https://en.wikipedia.org/wiki/Fuel_cell fuel-cell technologies] that combine hydrogen and oxygen to produce electricity. The oxygen require..."
= Fuel Cells =
There are several [ https://en.wikipedia.org/wiki/Fuel_cell fuel-cell technologies] that combine hydrogen and oxygen to produce electricity. The oxygen required for a fuel cell comes directly from the air. The hydrogen is not so readily available. It is difficult to distribute and [https://en.wikipedia.org/wiki/Hydrogen_storage store].
The electricity is used to turn a shaft motor, just like in a diesel-electric system. Current devices the size of a small piece of luggage can [https://www.fueleconomy.gov/feg/fuelcell.shtml power a car]. As fuel-cell technology improves, fuel cells may well be widespread in marine use. They are already powering submarines and yachts.
However, there are no practical alternatives to diesel fuel for ocean-going boats because of the need to fill up at a fuelling station and store highly compressed (and explosive!) hydrogen.
On the horizon for sea transportation are two promising fuel-cell technologies: Proton Exchange Membrane Fuel Cell (PEMFC) and Direct Methanol Fuel Cell (DMFC).<ref>Center for Renewable Energy & Sustainable technology, http://solstice.crest.org/hydrogen/hydrogen_fuelcell_intro.html</ref> They operate at a fairly low temperature (50-100 °C and 50-200 °C, respectively) compared to other fuel cell technologies, warm up quickly and don't require expensive containment structures.
DMFC fuel cells use a reformer to generate the hydrogen from some other fuel, such as methanol (wood alcohol). Methanol used to be distilled from wood but today is usually processed from natural gas.
A basic fuel cell is about 80% efficient at producing electricity. DMFCs are around 40% efficient.<ref>Center for Renewable Energy & Sustainable technology, http://solstice.crest.org/hydrogen/hydrogen_fuelcell_intro.html</ref>
But methanol reformers and fuel cells in combination are only about 30-40% efficient, so the overall efficiency drops to 24 to 32%, given a conservative electric motor efficiency of about 80%.
Another approach generates hydrogen from the electrolysis of water, using electricity generated from solar panels or wind turbines. This would make a boat completely independent of shore-based energy, but it is unlikely that a boat could support a sufficiently large installation of green energy generators.
== References ==
There are several [ https://en.wikipedia.org/wiki/Fuel_cell fuel-cell technologies] that combine hydrogen and oxygen to produce electricity. The oxygen required for a fuel cell comes directly from the air. The hydrogen is not so readily available. It is difficult to distribute and [https://en.wikipedia.org/wiki/Hydrogen_storage store].
The electricity is used to turn a shaft motor, just like in a diesel-electric system. Current devices the size of a small piece of luggage can [https://www.fueleconomy.gov/feg/fuelcell.shtml power a car]. As fuel-cell technology improves, fuel cells may well be widespread in marine use. They are already powering submarines and yachts.
However, there are no practical alternatives to diesel fuel for ocean-going boats because of the need to fill up at a fuelling station and store highly compressed (and explosive!) hydrogen.
On the horizon for sea transportation are two promising fuel-cell technologies: Proton Exchange Membrane Fuel Cell (PEMFC) and Direct Methanol Fuel Cell (DMFC).<ref>Center for Renewable Energy & Sustainable technology, http://solstice.crest.org/hydrogen/hydrogen_fuelcell_intro.html</ref> They operate at a fairly low temperature (50-100 °C and 50-200 °C, respectively) compared to other fuel cell technologies, warm up quickly and don't require expensive containment structures.
DMFC fuel cells use a reformer to generate the hydrogen from some other fuel, such as methanol (wood alcohol). Methanol used to be distilled from wood but today is usually processed from natural gas.
A basic fuel cell is about 80% efficient at producing electricity. DMFCs are around 40% efficient.<ref>Center for Renewable Energy & Sustainable technology, http://solstice.crest.org/hydrogen/hydrogen_fuelcell_intro.html</ref>
But methanol reformers and fuel cells in combination are only about 30-40% efficient, so the overall efficiency drops to 24 to 32%, given a conservative electric motor efficiency of about 80%.
Another approach generates hydrogen from the electrolysis of water, using electricity generated from solar panels or wind turbines. This would make a boat completely independent of shore-based energy, but it is unlikely that a boat could support a sufficiently large installation of green energy generators.
== References ==