Energy Efficiency Improvements Needed for Green Hydrogen Production

Hydrogen has many energy storage applications, including hydrogen fuel cells for electricity storage and vehicle power. Hydrogen (H2) is also an essential chemical feedstock for many industrial processes. It is produced using natural gas, oil, coal, and electrolysis; which account for 48%, 30%, 18% and 4% of the world's hydrogen production respectively. Fossil fuels are currently the main source of industrial hydrogen. The IEA reports that hydrogen will need to be 6% of world energy production in the transition to net zero, so green electrolysis methods need to be improved and displace much of the fossil fuel generated hydrogen as possible.

Currently electrolysis for hydrogen production is around 70-80% efficient, while steam reforming of methane using fossil fuels is 70-85% efficient, making it a more budget-conscious approach. If hydrogen is to be produced in greater quantities then the efficiency gap between green methods and fossil fuels needs to be addressed.

A team of researchers at Fraunhofer Institute for Reliability and Microintegration IZM in Germany claims to have found a practical and low-cost solution with zinc batteries with double efficiency and the ability to produce hydrogen. According to the researchers, "First tests promise fifty percent efficiency when storing power and eighty percent when producing hydrogen – with an estimated life expectancy of ten years," said a statement by the institute.

Other researchers in Korea and the USA are exploring the use of organometal halide perovskites (OHPs) for PEC water splitting, which seems to promise greater efficiencies, although this technique exists only in the laboratory currently. In a press release, Dr. Sanghan Lee, the lead author of the study from South Korea's Gwangju Institute of Science and Technology, emphasized, "Our study provides insights into the rational design of high-efficiency photoanodes based on organometal halide perovskites. This technology could play a vital role in advancing the hydrogen economy and promoting sustainable energy solutions."

Many universities and research institutes across the world are looking at ingenious methods to raise hydrogen production efficiency. The University of New South Wales in Australia is researching alternatives to platinum for hydrogen fuel cells, as the rarity and expense of platinum could be a bottleneck for this process. Progress in the field has been slow, as finding alternatives and testing their durability is a lengthy and expensive process. “For instance, creating a new hydrogen fuel cell catalyst can take up to a year, and then even longer to understand exactly what’s happening using expensive equipment that is hard to access,” said Dr Quentin Meyer of UNSW. Common alternatives like iron are simply not durable enough for electrodes.

In Israel, innovators are making H2 without toxic by-products by recycling factory waste. A research team from Sami Shamoon College of Engineering have developed a new green hydrogen production process using stainless steel powder. The electrochemical process releases H2 and the researchers say solar energy could be a complement to increase production. “Green hydrogen is made in a process devoid of carbon dioxide emissions,” said Dr. Guy Ben Hamu, the research team head. “We add a stainless steel powder to water then and through an electrochemical process produce hydrogen. We do not introduce any other energy to the water and the hydrogen is released from it spontaneously. In order to produce a large amount, solar energy can be added, and then more hydrogen can be produced in a short span of time.”

The problem with most of these ingenious projects is that they are not at commercial scale yet, and it seems will need much development before they can be utilized in a major way. Unfortunately, with this July being the hottest on record, climate change is moving fast and solutions need to be implemented quickly if we are to keep carbon emissions from doing even more harm to the global ecosystem.