It can be used in cars, in houses, for portable power, and in many more applications. Hydrogen is an energy carrier that can be used to store, move, and deliver energy produced from other sources. Today, hydrogen fuel can be produced through several methods.
The most common methods today are natural gas reforming a thermal process , and electrolysis. Other methods include solar-driven and biological processes. Thermal processes for hydrogen production typically involve steam reforming, a high-temperature process in which steam reacts with a hydrocarbon fuel to produce hydrogen.
Many hydrocarbon fuels can be reformed to produce hydrogen, including natural gas, diesel, renewable liquid fuels, gasified coal, or gasified biomass. Water can be separated into oxygen and hydrogen through a process called electrolysis. Electrolytic processes take place in an electrolyzer, which functions much like a fuel cell in reverse—instead of using the energy of a hydrogen molecule, like a fuel cell does, an electrolyzer creates hydrogen from water molecules.
Energy efficiency, renewable power, and direct electrification can reduce emissions from electricity production and a portion of transportation; but the last 15 percent or so of the economy, comprising aviation, shipping, long-distance trucking and concrete and steel manufacturing, is difficult to decarbonize because these sectors require high energy density fuel or intense heat.
Green hydrogen could meet these needs. Hydrogen is abundant and its supply is virtually limitless. It can be used where it is produced or transported elsewhere.
Unlike batteries that are unable to store large quantities of electricity for extended periods of time, hydrogen can be produced from excess renewable energy and stored in large amounts for a long time.
Pound for pound, hydrogen contains almost three times as much energy as fossil fuels, so less of it is needed to do any work. And a particular advantage of green hydrogen is that it can be produced wherever there is water and electricity to generate more electricity or heat. Hydrogen has many uses. Green hydrogen can be used in industry and can be stored in existing gas pipelines to power household appliances. It can transport renewable energy when converted into a carrier such as ammonia, a zero-carbon fuel for shipping, for example.
Hydrogen can also be used with fuel cells to power anything that uses electricity, such as electric vehicles and electronic devices. Fuel cells work like batteries: hydrogen is fed to the anode, oxygen is fed to the cathode; they are separated by a catalyst and an electrolyte membrane that only allows positively charged protons through to the cathode.
The electrons, meanwhile, travel via an external circuit—creating electricity that can be put to work—to meet the protons at the cathode, where they react with the oxygen to form water. Hydrogen Hyundai. Photo: Adam Gautsch. Hydrogen is used to power hydrogen fuel cell vehicles. Because of its energy efficiency, a hydrogen fuel cell is two to three times more efficient than an internal combustion engine fueled by gas.
Because they can function independently from the grid, fuel cells can be used in the military field or in disaster zones and work as independent generators of electricity or heat. When fixed in place they can be connected to the grid to generate consistent reliable power.
Its flammability and its lightness mean that hydrogen, like other fuels, needs to be properly handled. Many fuels are flammable. Compared to gasoline, natural gas, and propane, hydrogen is more flammable in the air.
However, low concentrations of hydrogen have similar flammability potential as other fuels. Since hydrogen is so light—about 57 times lighter than gasoline fumes—it can quickly disperse into the atmosphere, which is a positive safety feature.
Storing liquid hydrogen. Photo: Jared. Because hydrogen is so much less dense than gasoline, it is difficult to transport. Currently, hydrogen is transported through dedicated pipelines, in low-temperature liquid tanker trucks, in tube trailers that carry gaseous hydrogen, or by rail or barge. Today 1, miles of hydrogen pipelines deliver gaseous hydrogen around the U.
Natural gas pipelines are sometimes used to transport only a limited amount of hydrogen because hydrogen can make steel pipes and welds brittle, causing cracks. When less than 5 to 10 percent of it is blended with the natural gas, hydrogen can be safely distributed via the natural gas infrastructure. To distribute pure hydrogen, natural gas pipelines would require major alterations to avoid potential embrittlement of the metal pipes, or completely separate hydrogen pipelines would need to be constructed.
Fuel cell technology has been constrained by the high cost of fuel cells because platinum, which is expensive, is used at the anode and cathode as a catalyst to split hydrogen. Research is ongoing to improve the performance of fuel cells and to find more efficient and less costly materials.
A challenge for fuel cell electric vehicles has been how to store enough hydrogen—five to 13 kilograms of compressed hydrogen gas—in the vehicle to achieve the conventional driving range of miles. Hydrogen gas pump. Photo: Bob n Renee. The fuel cell electric vehicle market has also been hampered by the scarcity of refueling stations.
As of August, there were only 46 hydrogen fueling stations in the U. The various obstacles green hydrogen faces can actually be reduced to just one: cost. The fact that 70 million tons of hydrogen are produced every year and that it is shipped in pipelines around the U.
The problem is that green hydrogen currently costs three times as much as natural gas in the U. And producing green hydrogen is much more expensive than producing gray or blue hydrogen because electrolysis is expensive, although prices of electrolyzers are coming down as manufacturing scales up. Friedmann detailed three strategies that are key to bringing down the price of green hydrogen so that more people will buy it:.
The California National Guard designed hydrogen fuel cells that use solar energy for electrolysis to make green hydrogen. A McKinsey study estimated that by , the U. Friedmann believes there will be substantial use of green hydrogen over the next five to ten years, especially in Europe and Japan.
However, he thinks the limits of the existing infrastructure will be reached very quickly—both pipeline infrastructure as well as transmission lines, because making green hydrogen will require about percent more electricity capacity than we now have. Many experts predict it will be 10 years before we see widespread green hydrogen adoption; Friedmann, however, maintains that this year projection is based on a number of assumptions. Researchers are working on hydrogen storage, hydrogen safety, catalyst development and fuel cells.
Photo: Canadian Nuclear Laboratories. There are a number of green energy projects in the U. Here are a few examples. This innovative plant will use waste gasification, combusting 42, tons of recycled paper waste annually to produce green hydrogen. Because it does not use electrolysis and renewable energy, its hydrogen will be cost-competitive with gray hydrogen. A new Western States Hydrogen Alliance , made up of leaders in the heavy-duty hydrogen and fuel cell industry, are pushing to develop and deploy fuel cell technology and infrastructure in 13 western states.
Hydrogen Europe Industry, a leading association promoting hydrogen, is developing a process to produce pure hydrogen from the gasification of biomass from crop and forest residue.
Because biomass absorbs carbon dioxide from the atmosphere as it grows, the association maintains that it produces relatively few net carbon emissions. Breakthrough Energy , co-founded by Bill Gates, is investing in a new green hydrogen research and development venture called the European Green Hydrogen Acceleration Center. It aims to close the price gap between current fossil fuel technologies and green hydrogen.
Breakthrough Energy has also invested in ZeroAvia , a company developing hydrogen-fueled aviation. In December, the U. Ultimately, whether or not green hydrogen fulfills its promise and potential depends on how much carmakers, fueling station developers, energy companies, and governments are willing to invest in it over the next number of years. But because doing nothing about global warming is not an option, green hydrogen has a great deal of potential, and Friedmann is optimistic about its future.
We can even make negative carbon hydrogen with biohydrogen. And now we do. All comment about the production of green hydrogen is predicated on low-carbon electricity supply from wind and solar plants WASPs. Advanced nuclear power plants NPPs , by far the largest source of low-carbon electricity is wilfully ignored.
That infographic is completely misleading. There is a live debate in hydrogen technology over which production methods will win out. Green is the lowest carbon approach, because blue typically captures 85 to 90 per cent of the CO2 at best. While per cent of lost CO2 emissions may not sound like a lot, it could have significant climate change ramifications if production is scaled up. Advocates of blue hydrogen contend it will play a key role because it is so much cheaper than green hydrogen.
Some countries and companies think it could even play a big role in heating buildings, though others think ways of electrifying heating, such as heat pumps, are more likely to win out.
Aerospace firm Airbus believes hydrogen holds more promise for decarbonising planes than batteries because of the energy it can store by weight.
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