August 28, 2021, Brandenburg, Prenzlau: There is a hydrogen tank in the Enertrag hybrid power plant in Brandenburg. In the Enertrag hybrid power plant, green hydrogen is generated from wind power and fed into the gas network.
Photo by Fabian Sommer / picture alliance via Getty Images
Hydrogen is the simplest element and the most abundant substance in the universe.
When hydrogen burns, it generates energy in the form of heat and the only by-product is water. That means energy generated from hydrogen does not create atmosphere-warming carbon dioxide, making it one of many potential energy sources that could help reduce carbon dioxide emissions and slow global warming.
But to make hydrogen and convert it into a useful format, energy is required – and that energy is not necessarily renewable. This process is also inefficient and expensive compared to other forms of energy, whether renewable or not. Many critics say the hydrogen industry is a way for oil and gas giants to stop adopting pure renewable energy sources like sun and wind and give them “green” cover while maintaining demand for their products.
Despite the debate, companies and the US government are advancing the hydrogen industry.
“In my travels around the world, I cannot name a country that is not enthusiastic about hydrogen,” said John Kerry, the President’s special envoy on climate, at the Department of Energy’s Hydrogen Shot Summit last August. “From Saudi Arabia to India to Germany to Japan, we are building hydrogen partnerships around the world to advance this critical technology that every country knows has the potential to play a critical role in the clean energy transition.”
Hydrogen could grow to be a multi-trillion dollar global market, Kerry said, despite warning that China would dominate it.
What is green hydrogen, blue hydrogen, etc.?
The production of hydrogen costs energy because hydrogen atoms do not exist alone – they almost always cling to another atom, often to another element. (On earth, hydrogen is particularly common in the form of water or H2O.) The production of pure hydrogen requires breaking these molecular bonds.
In the energy industry, hydrogen is known in a variety of colors as an abbreviation for its origin.
One way to make hydrogen is through a process called electrolysis, in which electricity is passed through a substance to force a chemical change – in this case, breaking H2O into hydrogen and oxygen.
Green hydrogen is when the energy for electrolysis comes from renewable sources such as wind, water or sun.
Blue hydrogen is hydrogen made from natural gas using a steam methane reforming process in which natural gas is mixed with very hot steam and a catalyst. A chemical reaction takes place that creates hydrogen and carbon monoxide. Water is added to this mixture, which converts the carbon monoxide to carbon dioxide and more hydrogen. If the carbon dioxide emissions are then captured and stored underground, the process is considered climate-neutral and the hydrogen produced is referred to as “blue hydrogen”.
But there is some controversy over blue hydrogen because natural gas production inevitably leads to methane emissions from what are known as volatile leaks, which are methane leaks from the drilling, production and transportation process.
Methane doesn’t last as long in the atmosphere as carbon dioxide, but it is much stronger as a greenhouse gas. According to the International Energy Agency, one tonne of methane can be regarded as equivalent to 28 to 36 tons of carbon dioxide over 100 years.
Gray hydrogen Like blue hydrogen, it is made by reforming natural gas, but without efforts to capture carbon dioxide by-products.
Pink hydrogen is hydrogen produced by nuclear electrolysis that does not cause carbon dioxide emissions. (Although nuclear energy produces radioactive waste that must be safely stored for thousands of years.)
Yellow hydrogen is hydrogen, which is obtained from the energy network by electrolysis. The CO2 emissions vary greatly depending on the sources that supply the grid with electricity.
Turquoise hydrogen is hydrogen produced by methane pyrolysis or the splitting of methane into hydrogen and solid carbon with heat in reactors or blast furnaces. Turquoise hydrogen is still in the early stages of commercialization and its climate-conscious value depends on driving pyrolysis with clean energy and storing the physical carbon.
The color system is a little simplistic and needs updating and clarification, said Daryl Wilson, executive director of the coalition of the Hydrogen Council, an organization of industry CEOs.
“The color scheme isn’t helpful in the sense that it doesn’t get to the bottom line, which is the environmental properties of the hydrogen being produced,” Wilson told CNBC. “The main problem is that there has to be a methodology for tracking and declaring the specific CO² intensity of each hydrogen you are working with.”
Proponents say hydrogen is versatile but expensive
Hydrogen is already an important component of chemical industrial processes and in the steel industry. Making clean hydrogen for use in these industrial processes is therefore critical to reducing CO2 emissions, says Jake Stones of research firm Independent Commodity Intelligence Services (ICIS).
But as an energy source itself, hydrogen’s great advantage is its versatility, says Sunita Satyapal, who oversees hydrogen fuel cell technology for the Department of Energy.
“It’s often called the Swiss Army Knife of Energy,” she says.
According to Stones, clean hydrogen would be useful in decarbonizing heavy industrial transport such as trucks, large industrial boats, and planes.
It is less interesting for smaller consumer vehicles as battery-powered cars are used much more frequently. But larger vehicles require larger batteries, which increases their weight, which in turn increases their energy consumption. Hydrogen can be a way to get around this mystery.
Hydrogen can also be used to store energy from intermittent renewable sources, which are intermittent – the sun doesn’t always shine and the wind doesn’t always blow. Instead, energy providers can convert the excess energy into hydrogen and use it later as an alternative to battery storage systems.
Hydrogen “can be stored underground for as long as necessary, much like natural gas, and on a seasonal basis,” Stones told CNBC.
A hydrogen-powered vehicle refueling at the newly opened hydrogen refueling station operated by Saudi Aramco at the Air Products New Technology Center in Dhahran, Saudi Arabia, on Sunday June 27, 2021. Saudi Aramco outlines plans to invest in blue hydrogen while underway The world is turning away from dirtier forms of energy, but said it will be at least until the end of this decade for a global market for the fuel to develop.
Photographer: Maya Siddiqui / Bloomberg via Getty Images: Bloomberg | Bloomberg | Getty Images
The main disadvantage of hydrogen is its cost. It costs about $ 1.50 per kilogram to make hydrogen from natural gas, Satyapal said. Clean hydrogen costs around $ 5 per kilogram.
Last June, the Department of Energy launched a program called Hydrogen Shot, which aims to bring the cost of clean hydrogen down to $ 1 per kilogram in a decade.
Lowering the price of clean hydrogen “would be a big step in solving climate change,” said billionaire Bill Gates, founder of Breakthrough Energy Ventures, at the Department of Energy’s Hydrogen Shot Summit. “The goal of reducing the premium by 80 percent is a fantastic and ambitious goal,” he said.
The Department of Energy sees three main ways to reduce the cost of clean hydrogen from about $ 5 per kilogram to $ 1:
- Improving the efficiency, service life and production volume of electrolysers.
- Improving pyrolysis, which creates solid carbon rather than carbon dioxide as a by-product, Satyapal said.
- “Advanced Pathways”, which is a collective term for experimental technologies. One example is the photo-electrochemical (PEC) approach, which uses sunlight and special semiconductors to split water into sunlight and hydrogen.
Skeptics say it’s inefficient and impractical
While green hydrogen could be critical to decarbonising heavy industry, ship and aircraft engines, and perhaps storing energy, it is not efficient to use as a general source of energy, says Robert W. Howarth, professor of ecology and environmental biology at Cornell University.
Howarth is one of 22 members of the New York Climate Action Council, a group tasked with developing an implementation plan for the law that will make New York’s decarbonization plan mandatory. In the summer of 2020, natural gas industry stakeholders proposed using blue hydrogen in the existing natural gas pipeline infrastructure to heat houses.
But Howarth and Stanford professor Mark Jacobson published research in August showing that this was a bad idea.
“The bottom line is that blue hydrogen has huge emissions and only small percentages can be used in the current gas system,” Howarth told CNBC. “It is much cheaper to switch to electrically powered heat pumps for heating instead.”
Other critics say the problems with hydrogen are more fundamental.
According to Paul Martin, an expert in chemical process development and a member of the Hydrogen Science Coalition, the process of making hydrogen, compressing it, and then converting that compressed hydrogen into electricity or mechanical energy is extremely inefficient.
“It pays to accept a lot of problems with a battery because for every joule you put in, you get 90% back. That’s pretty great, ”Martin told CNBC. When producing and storing hydrogen, you only get 37% of the energy back. “So 63% of the energy you said is lost. And that’s the best case.”
But the idea of using hydrogen as a fuel is wrong, said Martin, who calls himself a lifelong environmentalist.
“The people who are really behind this hydrogen surge are the fossil fuels, because what are they supposed to do without them? current business. “
However, Martin thinks it is important to pursue green hydrogen for all other uses, such as industrial processes and the Haber-Bosch process, which converts hydrogen and nitrogen into ammonia for use in fertilizers. The Haber-Bosch process is credited with massively increasing food production and helping to feed the world’s exploding population over the past 100 years.
“I don’t want people to think I’m against hydrogen. I think it’s super important to make green hydrogen, ”said Martin.
“But it’s also very important to use it for the right things, not for stupid things.”