Hydrogen, the most abundant element in the universe, holds promise as the ideal energy storage medium. But extracting hydrogen sustainably (i.e., from renewable sources like water) is an expensive and energy-intensive process, which is why the overwhelming majority of our hydrogen supply comes from fossil fuels. We call this “grey hydrogen” (or “blue hydrogen” if the CO2 by-product is captured and stored). Since fossil fuels are a finite resource and their extraction methods (mining, drilling or fracking) are less than benign, to say the least, the Holy Grail of hydrogen is cost-effective water electrolysis using electricity derived from carbon-free, renewable energy—in other words, “green hydrogen.”
Remember the engineering adage that says, “You can have it soon, we can make it good, it can be cheap; pick any two.” Well, green hydrogen technology exists today and the product quality is good; it’s the “cost-effective” part that eludes the industry. So far, the proton-exchange membrane (PEM) electrolyzer is the leading contender, although its 70 percent efficiency drives up its cost per unit of energy. Nonetheless, experts estimate that by the end of this decade, green hydrogen can be cost-competitive with fossil fuels, so let’s take a look at some of the green hydrogen projects that are currently in the works.
European Union (EU)
The EU intends to become climate-neutral by the year 2050, which will require a healthy combination of efficiency, renewable energy, and green hydrogen production. Engineering.com has reported on individual green hydrogen projects in Germany and Denmark, which represent a small portion of the EU’s target of producing 10 Mt of green hydrogen annually by 2030.
As part of the UK’s Gas Goes Green initiative, natural gas provider SGN is launching a pilot project to transition from fossil fuels to clean-burning hydrogen. H100 Fife will use the 7-megawatt Levenmouth demonstration offshore wind turbine to produce green hydrogen via water electrolysis. The resulting hydrogen will be distributed to up to 300 customers who opt into the program. Participating customers will receive free hydrogen appliances to replace their existing natural gas appliances and will pay the same rate for hydrogen as they do for natural gas. SGN will operate a facility that demonstrates hydrogen appliances to customers who are considering making the switch. Although the pilot program will only involve 300 customers, the company’s new network will reach a thousand homes. SGN has partnered with the University of Edinburgh to conduct peer-reviewed research on the technical, social and economic performance of the hydrogen network. Officials expect a rollout sometime in 2022.
Linde Engineering is planning to build the world’s largest PEM electrolyzer, a 24-megawatt unit at the Leuna Chemical Complex in Germany. Some of the hydrogen produced at the facility will be distributed to industrial customers through the company’s hydrogen pipeline network, with the remainder being liquified and shipped to refueling stations. Linde says that the plant will produce enough hydrogen to provide 600 fuel-cell buses with a collective range of 40 million kilometers annually.
A consortium of companies, including one from the fossil fuel sector, is building Europe’s largest offshore wind-to-hydrogen project. Powered by an offshore wind farm in the North Sea, project NortH2 will develop a network of wind farms, electrolyzers, hydrogen storage units, and pipelines to deliver green hydrogen to industrial users. By 2040, the group expects annual production to reach a million metric tons—enough to reduce CO2 emissions by 10 megatons per year.
USA
Over the past few years, the U.S. has fallen behind the curve with respect to green energy, but that’s likely to change with the new administration. Like Europe, the U.S. efforts on green hydrogen are primarily centered on water electrolysis driven by wind and solar. SGH2, a Solena Group company focused on the gasification of waste into hydrogen, is taking a multifaceted approach to a sustainable future: waste to green energy. The company claims that producing hydrogen with its plasma-based gasification process “reduces carbon emissions by two to three times more than green hydrogen produced using electrolysis and renewable energy, and is five to seven times cheaper.” We've written about waste to energy before, but in those cases, the waste was converted into electricity, not hydrogen. Here’s how SGH2’s process works:
While watching that video, my first thought was, “What about the energy required to heat the plasma to 3500 ºC?” Well, SGH2 says that the heat comes from the resulting fuel itself, with no external energy required. (That doesn’t violate the laws of thermodynamics, since there’s energy in the waste product.) The process has been independently validated through technical feasibility studies by Shell New Energies and British Airways.
Based on its earlier prototypes, as well as a full-scale pilot project in Pennsylvania, the company believes that it can produce green hydrogen for just $2 per kilogram, which is comparable to the cost of producing grey or blue hydrogen from fossil fuels. That hypothesis will be tested at its new commercial facility, slated to be the world’s largest green hydrogen generator, in Lancaster, Calif. The municipality will provide SGH2 with 40,000 tons of waste every year—enough to produce 3,800 tons of green hydrogen. Lancaster will save more than $2 million every year in landfill costs, while hydrogen refueling stations in California will purchase the green hydrogen. Although I question whether they can make this as cost-effective as other hydrogen production methods, I do like the fact that it also addresses the solid waste issue.
Will It Fly?
Hydrogen may be the ultimate fuel, thanks to its high energy density and versatility. It burns cleanly in engines, can be converted directly into electricity via fuel cells, and, when blended with natural gas, can be distributed through modified natural gas pipelines. The resulting blend can be burned in natural gas appliances, resulting in lower greenhouse gas emissions, or the hydrogen can be extracted at the point of use. The main challenge with a green hydrogen economy is bringing down the cost. Two dollars per kg is the target, but with the current state of water electrolysis technology, that’s not likely to happen anytime soon. SGH2 claims that its plasma-based process can reach that goal, but the “Doubting Thomas” in me remains skeptical. But despite the hurdles, there’s no shortage of researchers, government agencies, private companies, and venture capitalists who are playing the long game by betting on green hydrogen. It’s a high-risk, high-reward scenario, but the renewable energy industry, much like the stock market, hedges its bets by diversifying.