Hydrogen - a versatile energy carrier

Hydrogen - a versatile energy carrier

Hydrogen is a versatile energy carrier, which can help to tackle various critical energy challenges. Hydrogen can be produced from almost all energy resources, though today’s use of hydrogen in oil refining and chemical production is mostly covered by hydrogen from fossil fuels, with significant associated carbondioxid emissions.

The big picture - Hydrogen: fuel of the future? | The Economist

It’s been hailed as fuel of the future. Hydrogen is clean, flexible and energy efficient. But in practice there are huge hurdles to overcome before widespread adoption can be achieved.

Derived from the most abundant element in the universe, hydrogen fuel is clean, flexible, and energy-efficient. Current projections indicate that by 2030 the hydrogen economy could be worth $500bn. Yet hydrogen power has had a historically bumpy ride - and there are still obstacles to widespread adoption. Could recent innovation, pushes to decarbonise the energy sector and a global interest in reaching a “net zero” world at last make hydrogen commercially viable?

Decarbonise through Hydrogen

Clean hydrogen, being produced from renewables, nuclear or fossil fuels with CCUS, can help to decarbonise a range of sectors, including long-haul transport, chemicals, iron and steel, where it is proven difficult to reduce emissions. Hydrogen can also help to improve air quality in cities and improve energy security.

Renewables in the electricity system

Hydrogen can also support the integration of variable renewables in the electricity system, being one of the very few options for storing electricity over days, weeks or months. Today hydrogen is mainly used in the refining and chemical sectors and produced from fossils, accounting for 6% of global natural gas use and 2% of coal consumption and being responsible for 830 Mtcarbondioxid of annual carbondioxid emissions.

Scale-up will be critical to bring down the costs of technologies for producing and using clean hydrogen, such as electrolysers, fuel cells and hydrogen production with CCUS.

Hydrogen and energy

Hydrogen and energy have a long shared history – powering the first internal combustion engines over 200 years ago to becoming an integral part of the modern refining industry. It is light, storable, energy-dense, and produces no direct emissions of pollutants or greenhouse gases.

But for hydrogen to make a significant contribution to clean energy transitions, it needs to be adopted in sectors where it is almost completely absent, such as transport, buildings and power generation.

The Future of Hydrogen provides an extensive and independent survey of hydrogen that lays out where things stand now; the ways in which hydrogen can help to achieve a clean, secure and affordable energy future; and how we can go about realising its potential.

Demand for Hydrogen

Supplying hydrogen to industrial users is now a major business around the world. Demand for hydrogen, which has grown more than threefold since 1975, continues to rise – almost entirely supplied from fossil fuels, with 6% of global natural gas and 2% of global coal going to hydrogen production.

As a consequence, production of hydrogen is responsible for carbondioxid emissions of around 830 million tonnes of carbon dioxide per year, equivalent to the carbondioxid emissions of the United Kingdom and Indonesia combined.

Hydrogen production

Hydrogen can be extracted from fossil fuels and biomass, from water, or from a mix of both. Natural gas is currently the primary source of hydrogen production, accounting for around three quarters of the annual global dedicated hydrogen production of around 70 million tonnes.

This accounts for about 6% of global natural gas use. Gas is followed by coal, due to its dominant role in China, and a small fraction is produced from from the use of oil and electricity.

The production cost of hydrogen from natural gas is influenced by a range of technical and economic factors, with gas prices and capital expenditures being the two most important.

Fuel costs are the largest cost component, accounting for between 45% and 75% of production costs. Low gas prices in the Middle East, Russia and North America give rise to some of the lowest hydrogen production costs.

Gas importers like Japan, Korea, China and India have to contend with higher gas import prices, and that makes for higher hydrogen production costs.

Keeping an eye on costs

Dedicated electricity generation from renewables or nuclear power offers an alternative to the use of grid electricity for hydrogen production.

With declining costs for renewable electricity, in particular from solar PV and wind, interest is growing in electrolytic hydrogen and there have been several demonstration projects in recent years.

Producing all of today’s dedicated hydrogen output from electricity would result in an electricity demand of 3 600 TWh, more than the total annual electricity generation of the European Union.

With declining costs for solar PV and wind generation, building electrolysers at locations with excellent renewable resource conditions could become a low-cost supply option for hydrogen, even after taking into account the transmission and distribution costs of transporting hydrogen from (often remote) renewables locations to the end-users.

Various uses for Hydrogen

Industry

Hydrogen use today is dominated by industry, namely: oil refining, ammonia production, methanol production and steel production. Virtually all of this hydrogen is supplied using fossil fuels, so there is significant potential for emissions reductions from clean hydrogen.

Transport

In transport, the competitiveness of hydrogen fuel cell cars depends on fuel cell costs and refuelling stations while for trucks the priority is to reduce the delivered price of hydrogen. Shipping and aviation have limited low-carbon fuel options available and represent an opportunity for hydrogen-based fuels.

Buildings

In buildings, hydrogen could be blended into existing natural gas networks, with the highest potential in multifamily and commercial buildings, particularly in dense cities while longer-term prospects could include the direct use of hydrogen in hydrogen boilers or fuel cells.

Power generation

In power generation, hydrogen is one of the leading options for storing renewable energy, and hydrogen and ammonia can be used in gas turbines to increase power system flexibility. Ammonia could also be used in coal-fired power plants to reduce emissions.

Practical opportunities through Hydrogen

Hydrogen is already widely used in some industries, but it has not yet realised its potential to support clean energy transitions. Ambitious, targeted and near-term action is needed to further overcome barriers and reduce costs.

The IEA has identified four value chains that offer springboard opportunities to scale up hydrogen supply and demand, building on existing industries, infrastructure and policies. Governments and other stakeholders will be able to identify which of these offer the most near-term potential in their geographical, industrial and energy system contexts.

Regardless of which of these four key opportunities are pursued – or other value chains not listed here – the full policy package of five action areas listed above will be needed. Furthermore, governments – at regional, national or community levels – will benefit from international cooperation with others who are working to drive forward similar markets for hydrogen.

Fuel cells and Hydrogen

In the medium to long-term, fuel cells (FCs) together with hydrogen fuel supply will offer an attractive potential clean energy solution. FCs can contribute significantly to sustainable and secure energy supply systems. The technology connects two basic future energy carriers: electricity and hydrogen.

FCs are electrochemical devices that convert fuel such as hydrogen directly to electricity without combustion. Hydrogen reacts with oxygen in the FCs to form water and releases electrons producing an electric current through an external circuit. Polymer Electrolyte Membrane Fuel Cell (PEM FC) technology is the most popular type of FC.

Current supply bottlenecks along the value chain through Hydrogen

Around 30 raw materials are needed for producing FCs and hydrogen storage technologies. Of these materials, 13 materials namely cobalt, magnesium, REEs, platinum, palladium, borates, silicon metal, rhodium, ruthenium, graphite, lithium, titanium and vanadium are deemed critical for the EU economy according to the 2020 CRM list. Materials and components along the supply chain are presented below.

The unique chemical and physical properties make PGMs excellent catalysts for the automotive industry. Today, platinum demand for FC applications is insignificant compared with other end-use applications. However, a FC vehicle needs 10 times more than the PGM loading of an average gasoline or diesel vehicle.

Platinum

According to the European Commission’s FC and hydrogen joint undertaking (FCH JU), the amount of platinum in the next generation of FC vehicles will reach similar levels to that used in the catalytic converters of diesel vehicles, which corresponds to 3-7 grams (Reuters Business News, 2018). This could significantly enable large-scale commercialisation of FC-powered vehicles. Most FCs have a standard design in which two electrodes are separated by an ion-conducting electrolyte.

Membrane Electrode Assembly

The heart of a PEM FC is the membrane electrode assembly (MEA), which includes five basic components: membrane, anode catalyst layer, cathode catalyst layer and two gas diffusion layers (GDLs) one for each electrode. On overview of the raw materials adopted in FCs is shown below. The materials and components related to the hydrogen production and storage were also considered in this analysis.