Could hydrogen be the key to helping us transition to a sustainable future?
Hydrogen is seen as part of a low carbon future by the government and businesses. Governments around the world, including the United States, various European countries, China and the UK are all investing in hydrogen technologies. But what is it, how is it produced, and how might it be used?
What is it?
Hydrogen, as you might remember from school science class, is one of the most common and simple elements on the planet. Whilst it is found in plants, minerals, animals, and humans, it is rarely available in its gas form.
Hydrogen in its gas form will be most beneficial to the net-zero transition. The gas can be used instead of methane, which is also called natural gas. Like natural gas, hydrogen can be burnt.
The process of burning breaks the chemical bonds between the elements. The separated elements are then released into the air. Burning natural gas releases carbon dioxide, a pollutant.
The UK uses a lot of natural gas, particularly to heat our homes since natural gas is a cleaner alternative to coal. However, hydrogen is the cleanest option as burning it only releases water vapour.
How can we produce hydrogen?
The problem with hydrogen as a fuel source to create energy is that we need to make hydrogen first. There are many ways to do this, but different processes define whether the hydrogen is considered blue or green hydrogen. Blue hydrogen comes from non-renewable sources, and green hydrogen comes from renewable sources.
Blue hydrogen often comes from a process known as reforming. This process involves putting carbon dioxide or methane together with other gases such as steam or oxygen in a high-pressure and high heat environment. A catalyst - a substance that helps speed up the reaction - is added. The product of this process is hydrogen and greenhouse gases such as carbon dioxide. This process also takes a lot of energy to create the required heat and pressure.
Green hydrogen is more environmentally friendly. The main form of green hydrogen involves using electricity to separate the hydrogen and oxygen atoms in water to create a pure source of hydrogen. This electricity can come from renewable sources, such as wind, solar, or wave. Creating hydrogen this way is a good use of any spare electricity produced during very sunny or windy days. This process doesn’t result in any harmful products.
There are also process that allow biological reactions from algae and microbes to produce hydrogen, but these are still in development.
What can we use hydrogen for?
The UK Government has set out its hydrogen strategy in a paper published in 2021. It imagines a future in which hydrogen is used alongside other energy sources, such as wind and solar, for a low carbon country.
One of the most obvious uses for hydrogen is as a replacement for natural gas to heat our homes. There are already some companies that can install boilers that work with a hydrogen and natural gas blend, such as Worcester Bosch.
The government is looking at how a mix of natural gas and hydrogen can be used safely in home boilers to reduce the carbon emissions of heating. It may also be possible that hydrogen-powered cookers will be found in homes across the UK in the future.
Industry processes may also use a lot of hydrogen energy in the future. Industry produced 16% of emissions in the UK in 2018. Hydrogen for industrial heating is one of the most likely uses for processes such as melting glass in a furnace. Other manufacturing processes that require melting through intense heat may also use hydrogen power.
Heavy vehicles that cannot easily use electric batteries such as HGVs, buses, cargo ships, planes, or trains might use hydrogen. Hydrogen is better for these sorts of vehicles because it can provide more power than electric batteries, and refuelling can happen in much the same way as it does now with petrol and diesel.
Big-name car manufacturers like Toyota have already produced hydrogen-powered cars, but a lack of hydrogen refuelling stations has meant that they haven’t been popular so far. However, if hydrogen vehicles become more common more hydrogen fuelling stations might be built. Aberdeen City Council, for example, has added a hydrogen-powered waste truck to its fleet.
There are already many companies and universities that are working out different innovative ways of using hydrogen. Cadent, the largest natural gas distribution in the UK, has worked with the government department for housing and the environment to supply solely hydrogen-powered appliances. These were used in show homes in Gateshead, UK, which are the UK’s first homes with solely hydrogen-fuelled appliances.
We have a long way to go before hydrogen is a common low carbon fuel. The government’s hydrogen strategy promises to fund lots of trials and experimentation to help develop new technology.
The UK still needs to develop the pipe networks and other distribution mechanisms for hydrogen and work out many of the regulations and safety requirements for this new fuel source. However, it does offer a lot of potential, and we can expect to see significant progress towards hydrogen in the next few decades.
By Keziah Watson ©
Comments