Hydrogen choices

Hydrogen has for several decades been touted as the fuel of the future. It is in fact a big commodity today, and heading for fast growth in a low-carbon future. If it is produced from fossil fuels, which is what Preem plans for, it is not part of the solution, but a big source of CO₂.

Wind power and photovoltaic solar power now supply cheaper kilowatt-hours than new fossil power in most parts of the world. For a 100 per cent renewable-powered world, something has to balance the intermittent wind and sun. Part of that balance can be batteries, electric cars, demand-side management, bio-power, hydro, solar thermal (where the heat can be stored), but more is probably needed.

Many see hydrogen as the missing link, one of the few options for long-term, even seasonal storage.

Hydrogen is very versatile. It can be used for industrial or domestic heating, for electricity production on a small scale with fuel cells or on a big scale with gas turbines or steam turbines, as a reducing agent in the metallurgical and chemical industries, and as vehicle fuel. It can, to some extent substitute for natural (fossil) gas within the existing pipeline system. It can fuel cars such as the Toyota Mirai, possibly with a better range and lower cost than battery cars. It can fuel heavy vehicles and airplanes, for which batteries are not an option.

A recent report from the IEA¹ states: “There have been false starts for hydrogen in the past; this time could be different. The recent successes of solar PV, wind, batteries and electric vehicles have shown that policy and technology innovation have the power to build global clean energy industries.”

Hydrogen is used in large quantities: 69 million tonnes per year, equivalent to almost 200 million tonnes of oil. It is now mainly used in the oil industry and for ammonia production.

Hydrogen use, storage and transport is a proven technology on an industrial scale. Many hundreds of kilometres of pipelines are in operation. Storage is so far on a more modest scale (a thousand tonnes) but geological storage of natural gas is huge, and hydrogen could be stored in the same way, at the same sites.

Hydrogen is clean at the point of combustion, often not emitting anything more than water vapour. But most hydrogen is produced from steam reformation of natural gas, some from coal. CO₂ emissions from hydrogen production are about 830 million tonnes per year.

Less than one per cent of the hydrogen is actually produced by the electrolysis of water.

CO₂-free hydrogen could be produced by several methods:

1. Electrolysis of water from nuclear power. Comment: Nuclear power is not considered clean by everybody. It is stagnant, at best, in most of the world. New nuclear is expensive.
2. High-temperature processes for splitting water, using heat and electricity supplied by nuclear power of new kinds. Comment: High-temperature helium-cooled nuclear reactors were developed in the 1950s to 1988 with poor results in the US, UK and Germany. The concept was revived in 2001 as part of Generation IV by the new Bush administration, but nothing much happened. A long shot.
3. Methane splitting. Natural gas consists mainly of methane, and if the four hydrogen atoms are separated from the single carbon atom, in an electrically heated plasma, the result is graphite or “carbon black” and hydrogen. Comment: Annual global demand for carbon black, used in tires, rubber, printers and plastics is 12 million tonnes, which could be produced in association with the production of 4 million tonnes of hydrogen. Even if economically viable, it is of marginal importance.
4. Fossil hydrogen production but with carbon capture and storage, CCS. Comment: CCS was also launched in 2001 by the Bush administration, but despite a huge world-wide effort, it has delivered very little apart from enhanced oil recovery, i.e. using CO₂ to squeeze more oil from wells with declining production. It has not demonstrated any significant CO₂ reduction anywhere.
5. Water electrolysis with renewable electricity. Comment: If hydrogen is going to play a major part in the future energy system, this is it. It will be very difficult to market hydrogen cars and other applications unless the hydrogen can be produced cleanly and easily and on a large scale fairly soon.

The IEA expects electrolytic hydrogen to cost $2.8/kg in 2030, much more than hydrogen from fossil gas ($1.8/kg with no carbon cost, some $2.2/kg with carbon cost). This is calculated using an electricity price of 4 cents/kWh. But at good locations, costs are much lower than that, at least some of the time.

Large amounts of wind power are being built in Sweden and Norway with insignificant subsidies, and auction prices of 2 cents have recently been reported from Los Angeles and Brazil.

In Germany and Denmark, prices are sometimes even negative.

There are 8640 hours in a year, and if hydrogen is produced for 4000 or 5000 of these hours, when the price is low enough, the electricity at good locations should cost well below 4 cents.

It may still be cheaper to produce hydrogen from fossil gas, but that does not matter if it is seen as unacceptable in most countries, and by consumers.

There is no way to say how much hydrogen the world will use in 2025 or 2040, but it is likely that it will increase from now, perhaps by a large factor. If nothing else, it is needed in biorefineries, for fuels and making plastic from wood.

That hydrogen has to be produced sustainably.

Fredrik Lundberg

¹ The Future of Hydrogen: Seizing Today’s Opportunities June 2019 at iea.org