Green hydrogen is better than blue for both cost and emissions, says study
November 23, 2021Researchers from an Australian study underscore that using fossil fuels to make H2 is highly polluting.
Green hydrogen produced using processes powered by renewable energy such as solar and wind is less expensive than blue H2 produced using fossil fuels and carbon capture and storage technology, say researchers from the Australian National University (ANU).
The researchers published a paper in which they compared the financial and environmental costs.
The paper was published in the Applied Energy peer-reviewed engineering journal. In it, they stated that both the emissions and financial costs from producing H2 using fossil fuels and storing captured carbon emissions was greater than that of producing green hydrogen with renewable energy.
This cost comparison is an interesting one as one of the most significant barriers to renewable H2 adoption is that it is viewed as more expensive to produce than forms made using fossil fuel such as natural gas, followed by carbon capture and storage (CCS) to help control the resulting greenhouse gas emissions. Many countries that have hydrogen plans have been focusing on blue H2 for this reason. Australia’s former chief scientist Dr. Alan Finkel endorsed the use of blue H2 as a path to building industrial capability.
ANU researchers found other substantial drawbacks in blue H2 over green hydrogen.
The ANU researchers said that even with CCS, blue H2 produced using fossil fuels would still cause “substantial” greenhouse gas emissions. They determined that current estimates show that CCS fails to capture methane emissions. That greenhouse gas is notably more potent than CO2 and is emitted in large amounts during natural gas extraction.
As those emissions are not captured by CCS, the methane emissions would continue rising due to the extraction of the natural gas. Moreover, because the production of H2 using natural gas is not fully efficient, it requires more gas to produce the H2 than would be needed to simply burn the natural gas as a fuel in the first place. The researchers stated that these emissions will only continue rising as extraction increases to meet export market needs.
On the financial side, the researchers stated that blue H2 using CCS becomes more expensive as a facility approaches 90 percent emissions capture, because it gets harder to capture CO2 as its concentrations lower. However, green hydrogen is reducing in cost – something the researchers expect to continue quite quickly with rising demand – to the point that researchers see a far greater financial incentive to invest in green over blue.
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I completely agree that green hydrogen from renewables is the least expensive way to produce clean hydrogen, however there is a problem, which is that the world does not have sufficient GREEN HYDROGEN PRODUCTION CAPACITY to meet the present needs of industry as well as the needs of emerging technologies, in particular transport for some cars, heavy transport and shipping, so the world needs to ramp up the present production of grey hydrogen in the short term produced by reforming fossil methane with steam, and capture the resulting CO2 (9.3 tons CO2 for every ton of hydrogen) (by CCS) as much as possible leaving blue hydrogen, but the capacity for CCS is almost zero at present so that needs to be ramped up too. So we have stepping stones to 2050 starting now with mainly grey hydrogen, then more blue hydrogen and finally only green hydrogen.
Green hydrogen electrolyzed from stranded renewable electricity, wind, solar, tidal, that is not needed during off peak grid requirements, is, except for Maintenance costs of equipment, very close to being without cost. Using this energy stream has been part of the strategy of expanding the uptake of hydrogen fuel cell vehicles.
Something I don’t see mentioned in any articles that scoff at the move toward using hydrogen and fuel cells for vehicle power is that oil companies often inject hydrogen into gasoline to make it “cleaner”. This hydrogen is made by reforming natural gas on a massive scale. Not doing that would have an effect on GHG emissions beyond what is being calculated by just eliminating the use of gasoline that isn’t fortified with hydrogen.
Green H2 outsmarts other colors of H2 in all respects. Embarking into the production of Blue H2 is not justified for many reasons such as
– CH4 emission.
– Additional Installation plant for Carbon capture, Transportation, sequestration or utilization etc, these are not only capital cost adder but also burn energy – that may not be renewable.
– the retention of of CO2 by Sequestration in underground has no confirmed study or evidence that it will not start surfacing out through porous geology at some point of time slowly or vigorously.
– Electrolyzer for Green H2 is easy to operate and maintain than massive blue H2 value chain/infrastructure.
– Green H2 infrastructure is simple to digitalize and remotely controlled under Industry 4.0.
Green Hydrogen can be produced from Renewable Natural Gas which, unlike fossil natural gas, is a Renewable form of energy. The carbon capture when producing RNG from biogas from organic waste sites (farms, municipal waste, landfill gas, and food spoilage) significantly reduces the Greenhouse Gas emission from these organic sites. It is also an effective way to manage the organic waste with a byproduct of RNG and organic fertilizer from the “digestate” left after capturing the biogas. The production of Green Hydrogen from RNG can be done “on site” using a HyGEAR unit at the hydrogen filling station or the industrial user of hydrogen. The RNG can be transported to the HyGEAR unit using existing natural gas infrastructure allowing the Renewable Electricity from wind/solar/hydro farms to be used more efficiently as electricity rather than converting to GsLRNGreen Hydrogen. Use this electricity to replace the electricity presently produced by coal burning power plants.