Hydrogen-Powered Ferry Promises Cleaner Air

But how the hydrogen is produced also matters

A rendering of a "zero emission," hydrogen powered ferry
A rendering of a "zero emission," hydrogen powered ferry

Note: Metropolitan Shuttle, a leader in bus shuttle rentals, regularly sponsors coverage on Streetsblog San Francisco and Streetsblog Los Angeles. Unless noted in the story, Metropolitan Shuttle is not consulted for the content or editorial direction of the sponsored content.

An Alameda-based company, Golden Gate Zero Emission Marine, will receive a $3 million grant from the California Air Resources Board (CARB) to build a prototype hydrogen-powered, fuel-cell ferry.

As Zero Emission Marine’s web page puts it: “Hydrogen is the simplest element consisting of only one proton and one electron. It is the most plentiful element in the universe and extremely high in energy.”

The kind of hybrid, battery powered/hydrogen-powered fuel cell electric technology the company is talking about has great promise to reduce overall emissions and should certainly reduce local emissions of dangerous particulates and noxious gases. And Streetsblog, of course, supports an expansion of ferry services–regardless of motive power–to get more people out of the most inefficient and dangerous urban transport mode: automobiles.

But it’s important not to lose track of what hydrogen is and what it isn’t.

Pure hydrogen doesn’t exist naturally on earth (except in trace quantities). It’s bound to other molecules, such as in H2O. It’s also found in hydrocarbons, such as gasoline, natural gas, etc. So it can’t just be extracted from the ground. It has to be manufactured.

That takes energy. Hydrogen can be made in two ways.

The first is electrolysis, which consists of using electricity to split water into hydrogen and oxygen. Recombine them in a fuel cell later and you get most of the electricity back, to run a ferry, or a car, or whatever you wish. Hydrogen is a way to store electricity, like a battery, more than it is a fuel. But it’s also only as clean as the plant that generated the electricity in the first place.

The far more common way of producing hydrogen is to use steam to extract it from hydrocarbons such as methane (The Department of Energy has a good web page that explains this process). The byproducts from that, unfortunately, are carbon monoxide and carbon dioxide. It also requires energy to heat the steam.

How much energy is consumed to compress hydrogen to between 5,000 and 10,000 pounds per square inch? How much energy is consumed shipping it and storing it safely? The startup’s web page says hydrogen is “extremely high in energy.” But the energy density of diesel fuel, which the ferries currently use, is about four times that of compressed hydrogen. Depending on how it is produced, overall emissions can be higher to extract hydrogen than just burning the fuels in the car or ferry directly.

In either case, as Streetsblog USA laid out in a post about hydrogen-powered, ‘environmentally friendly’ Hummers, the takeaway is that it takes more energy to manufacture hydrogen than the hydrogen itself produces.

“Most hydrogen is made from natural gas, [and] though hydrogen made by electrolysis using renewable energy sources such as wind, solar, and hydro is on the rise, it is still more expensive,” wrote Joseph Pratt, CEO of Zero Emission Marine, in an email to Streetsblog. “Since we are working on a fixed budget from CARB, we will choose whichever source of hydrogen will fit within our budget.”

But as Pratt also pointed out to Streetsblog, powering a ferry from hydrogen means they can switch to fully renewable hydrogen as soon as it becomes economical. So the question for policymakers is not so much whether an emissions-free, hydrogen-powered ferry can be built–it’s about how to make sure the hydrogen it uses really comes from clean sources.

  • LazyReader

    Hydrogen fuel cell vehicles are a gimmick whose time came and went fast. By
    the time fuel cell technology became equitable enough to be put in a
    car, battery electric cars were already as effective. Their horsepower
    is roughly the same; between 140-160. The only advantage the fuel cell
    car has is refill time is a fraction that of recharge time. But other
    than that it has numerous disadvantages.

    – There’s no nationwide hydrogen infrastructure to refuel these
    vehicles. Almost all of them are in California, the LA, SF and
    Sacramento area, Even modifying gas stations with say, one hydrogen pump
    would take years to accommodate a market of suburban drivers. Battery
    electric cars on the other hand, have a very simple infrastructure; a
    plug and an extension cord.

    – Hydrogen has a much lower energy density than gasoline. So a lot of it
    is necessary, even compressed at 700 bar filling up a tank would cost
    about 50 dollars for a range of about 350-400 miles ( 8 miles for every
    dollar or 422 feet per penny). With hyundai stating hydrogen prices
    could come down to 32 dollars that’s still a mesely 12.5 miles per
    dollar. Electricity Prices in the US costs an average of 12 cents per
    kilowatt-hour. So a 60 Kilowatt-hour battery on the Chevy Bolt would
    cost $7.20 to charge. With a 238 mile
    range (33 miles per dollar 1/3 of a mile per penny), three times the
    range per dollar spent and the second generation Bolt which will come
    out no doubt in 3-4 years the range will improve to about 250-350 mile
    range; even if the price of electricity doubled it’s still cheaper than a
    tank of hydrogen.

    – Hydrogen doesn’t exist in pure form naturally, it’s bound in
    hydrocarbons, organic hydrates or water. Manufacturing hydrogen uses
    lots of energy, rather than lengthy distribution networks; skipping that
    even if hydrogen were manufactured on site using electricity and
    municipal water at each filling station; even so rate of production
    would be slow.

    – As the lightest element in the universe, hydrogen escapes all
    containers no matter how well sealed.

    – The US alone manufactures 10 million tons of hydrogen a year, nearly
    all of it goes to the petro industry. To satiate the automotive/truck
    demand the US would require 10 times as much.

    – Next generation battery technology will offer faster recharge times;
    with more capacity.
    Instead of focusing on hydrogen, the industry should manufacture
    hydrocarbons using high temperature reactors or renewable energy and
    catalysts. These hydrocarbons can be blended to make a gasoline
    substitute which is liquid at room temperature. Using CO2, methane
    (atmospheric capture) and water as the feed stock, the fuel can be
    manufactured over and over again from the very pollutants it emitted in
    the first place.

  • crazyvag

    Curious about a comparison of energy density of batteries vs hydrogen vs diesel. Also, let’s assume renewable energy source, what percentage is lost as part of generation and transmission for hydrogen and battery.

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