Photo: Idun Haugan / NTNU

Hydrogen from A to Z

Hydrogen is found in large quantities on Earth, can be used in many contexts and is being promoted as an important solution in the transition to climate-friendly energy. But hydrogen investment also generates heated debate. So what’s the deal with hydrogen?

As much as 90 per cent of all atoms in the universe are hydrogen atoms. Hydrogen is the lightest, smallest and most common of all the elements. It has the atomic number one in the periodic table.

Hydrogen is also plentiful on Earth, where a lot of the hydrogen is bound in water. The water molecule consists of two hydrogen atoms and one oxygen atom (H2O).

In the Earth’s crust, every sixth to seventh atom is a hydrogen atom. Most hydrogen atoms are chemically bound together with other atoms, including in gas, petroleum, proteins, carbohydrates and fat.

Pure hydrogen therefore needs to be produced, or extracted, from hydrogen-containing raw materials such as gas or water.

Many areas of use

Hydrogen has versatile properties and can potentially be used in many ways, including as a replacement for fossil energy sources like oil and coal.

Hydrogen is considered one of the main factors, or drivers, in the green shift.

Hydrogen’s role in the energy transition is seen as a clean and climate-friendly alternative to fossil fuels in heat and electricity production. Due to its versatility, hydrogen can also replace fossil fuels in industrial processes, such as coal in the steel industry. It can be used as fuel in the transport sector, in particular shipping and aviation.

Hydrogen as an energy carrier

Hydrogen is an energy carrier. This means that hydrogen is not a direct source of energy like sunlight, wind energy or fossil fuels such as oil and coal. An energy carrier can be used to hold energy and store it for later use.

The most common and simplest way to store the hydrogen is in tanks with very high pressure. The stored energy can be extracted in several ways and used in various contexts.

Green hydrogen

Hydrogen as an energy carrier is particularly relevant when it comes to storing energy from solar cells and wind power. The challenge that these renewable energy sources present is that they produce uneven amounts of power, based on weather conditions.

When wind power and solar cells produce lots of energy, the excess power (electricity) can be used to produce so-called green hydrogen. This can be stored for later use when low wind or low sun levels create a power deficit.

Hydrogen storage can thus be used to balance the power supply.

How green hydrogen is produced

Hydrogen can be produced through the electrolysis of water. Electrolysis uses electrical energy to split water into hydrogen and oxygen. Electrolysis involves converting electrical energy into chemical energy. This way of producing hydrogen is considered environmentally friendly and emission-free if the electrical energy comes from renewable sources, such as solar, wind or hydropower. Hydrogen produced in this way is called green hydrogen.

Old method

Electrolysis has been used for 100 years, including by Norsk Hydro, which initially based its large fertilizer production on hydrogen produced by the electrolysis of water. The process required a lot of power, but Norway had plenty of electricity through its plentiful access to and development of hydropower.

The main objection to producing green hydrogen is that a lot of electricity is required for the electrolysis process. Critics of green hydrogen question how energy efficient this process is.

The point of contention is that even more renewable energy must be developed to produce enough hydrogen, which in turn requires developing even more land for renewable energy such as wind power. And land is a scarce commodity.

Blue hydrogen

The blue hydrogen process involves extracting hydrogen from natural gas, such as from gas reserves on the continental shelf – that is, from a fossil energy source. Through chemical processes, hydrogen and CO2 are separated out from the natural gas.

Carbon capture is necessary for blue hydrogen to be climate-friendly. This involves storing the CO2 in a way that does not contribute to greenhouse gas emissions.

In Norway, this can be accomplished by sequestering the CO2 under the seabed on the continental shelf, where the natural gas is extracted from. Separating out the CO2 and storing it in an emission-free place leaves pure hydrogen.

Blue hydrogen can then be used in the same way as green hydrogen.

Grey hydrogen

Grey hydrogen is produced from natural gas, oil or coal, without any carbon capture and storage taking place in the process. All the CO2 from the fossil fuels used to produce the hydrogen is released, resulting in a solution that is not climate friendly.

Hydrogen in history

Hydrogen is nothing new in the energy context. Water electrolysis and fuel cells were demonstrated already in the 19th century. Hydrogen has been used in hot air balloons and airships, and later also in expeditions into space.

Norsk Hydro used electrolysis of water to produce hydrogen as an input factor for artificial fertilizer for a good part of the last century.

Research was carried out on hydrogen as rocket fuel and later as aviation fuel from the end of World War II and through the 1950s. It was launched as a fuel in cars already in the 1970s, but this has taken time to develop.

Hydrogen in vehicles

Hydrogen fuel cell electric cars have not yet taken off in Norway. At the end of 2021, 195 cars, four trucks and one van were registered, according to Statistics Norway. However, the trucks were the world’s very first hydrogen-powered trucks.

A hydrogen vehicle is an electric car in which the battery is combined with a fuel cell and hydrogen tank. What we are calling hydrogen cars today do not use hydrogen as fuel in an internal combustion engine, but as an energy carrier to produce electricity in fuel cells.

The fuel cells convert the hydrogen that is stored in tanks on the vehicle, as well as oxygen from the air, into electricity and water vapour. Hydrogen-powered vehicles therefore have no local emissions other than water.

The electrical current then drives the electric motor which provides propulsion. In this sense, it is an electric car that uses fuel cells as an energy source.

In industry

Hydrogen can also be used in industrial processes. Fossil fuels like oil or gas can be replaced with hydrogen in industries such as cement production, aluminium production and in smelters.

Norway’s silicon industry could be one of the first to use hydrogen, while in Europe the steel industry will probably be the first. The Swedish mining company LKAB reports that producing green hydrogen for the steel industry is already profitable.

Should Norway invest in hydrogen?

This is where the big discussion enters in and where numerous opinions circulate about what is smart for Norway – and Europe.

Norway’s Ministry of Petroleum and Energy has launched an external investigation into how the state can contribute to building a coherent value chain to produce hydrogen with low or no emissions, where production, distribution and use are developed in parallel.

“The government will contribute to building a coherent value chain for hydrogen produced with low or no emissions. It is necessary to look at production, distribution and use together, and develop them in parallel,” says Minister of Petroleum and Energy Terje Aasland (Ap) in a press release.

NTNU, SINTEF, Greensight and Oslo Economics are the research institutions that are carrying out the investigation for the government. The study will be ready by the summer of 2023.

Here you can read about the government’s hydrogen strategy, which was presented in 2020.

Cooperation between research and industry

HYDROGENi – the Norwegian research and innovation centre for hydrogen and ammonia – is a research centre for environmentally friendly energy (FME) that was established in 2022. It will play an important role in the research and industrial development of hydrogen going forward.

SINTEF hosts HYDROGENi, and NTNU is partnering with the University of Oslo, the University of Tromsø, the University of Southeast Norway and the Department of Energy Engineering. Many industrial partners, including Equinor and Gassco, are in the centre in addition to the research institutions.

“In order to realize hydrogen’s full potential, we need to develop a lot of new knowledge and new technological solutions, as well as study how we can build a sustainable hydrogen economy,” said Rector Anne Borg during the opening of the centre.

The HYDROGENi research centre is very important for Norway because it increases knowledge-based activity along the entire value chain: from production to use in various areas, such as transport, stationary energy and in industry.