Hydrogen: putting the 'new' in 'renewables'

In recent years, the building industry has been supporting the sustainability movement within construction, promoting offerings that are ‘net zero’, ‘carbon neutral’ and ‘renewable’.

The word ‘renewable’ is defined as ‘a form of energy which can be produced as quickly as it is used’. This means the only truly renewable energy sources are the sun, water and wind.

On the other hand, renewable technologies promise cleaner energy production than fossil fuels and should minimise environmental impacts. They produce more energy than the power they consume.

Hydrogen can be used as a replacement for natural gas and can produce zero carbon emissions. Therefore, hydrogen could be the perfect alternative fuel for not just UK homes, but industries such as manufacturing, transport and commercial buildings and for National Grid backup.

Hydrogen has been used for many years and has historically been trialled in the UK gas network, but latterly phased out.

Several cities across the UK have recently pledged to introduce hydrogen measures. Swindon plans to blend hydrogen into its gas network and become Britain’s first hydrogen town. Wales & West Utilities also plans a 20% hydrogen blend by 2030 and 100% by 2050.

Depending on how it is produced, hydrogen can be classified as a renewable technology. Although there is only one chemical makeup of hydrogen, it can be created differently.

Green Hydrogen

The only proper CO2-free emission solution is green Hydrogen. It is created using renewable energy from solar, wind and wave farms. It uses electrolysis to split water into Hydrogen and oxygen. Currently, green hydrogen demonstrates a 46% efficiency rating.

It plays a massive part in the transition to a net zero economy. Several governments across the world are green hydrogen advocates. However, we must first decarbonise existing energy systems and provide enough renewable energy sources to cope with the demand.

Blue Hydrogen

Blue hydrogen is manufactured by splitting methane into hydrogen and carbon dioxide from steam reformation using natural gas. Blue hydrogen is 58% efficient.

The carbon is stored using capture technology. Blue hydrogen can significantly minimise the impact of hydrogen generation, by capturing a high percentage of the carbon at generation.

Grey Hydrogen

Grey hydrogen is the most common method of hydrogen generation and unfortunately, the most carbon-intensive, especially at an industrial scale.

Like blue hydrogen, it’s created by steam reformation, however using fossil fuels including coal. The defining characteristic of grey hydrogen is that it does not capture carbon.

The Hydrogen Solution

Like most good things, hydrogen comes with a cost. Transport and shipping are likely to be the first large-scale industries likely to adopt hydrogen technologies.

The construction industry will consider it as a long-term strategy as it waits for the cost of hydrogen production to decrease and the efficiency of production to increase.

Considerations

Heat pumps are still far more efficient despite the O-zone depleting qualities of refrigerants. Heat pumps offer a 270% efficiency using green electricity off the grid.

Although green hydrogen produces much less carbon pollution, it generates nitrous oxide when it combusts. Nitrous oxide impacts air quality, which contradicts the Government’s plan to improve air quality across UK cities. With future health crises at stake from the effects of climate change, the introduction of hydrogen begs the question of balance. If renewable technologies disregard other pollutants, the carbon problem could materialise as an air quality problem.

Building systems utilising hydrogen should include measures to reduce and combat pollutants.

For more information, please contact Luke Yeates-Mayo. Luke sits on the Welsh Hydrogen Trade Association which advises the Welsh Government on the future of Hydrogen.?