Engineers say there is no technical reason why hydrogen cannot replace natural gas to make electricity, heat homes and for cooking.
LONDON, 17 June, 2019 − The UK government, which has just declared it aims to reach zero carbon emissions by 2050, has been told by Britain’s leading engineers that hydrogen can safely be used to replace natural gas in the country’s gas grid.
Since 85% of homes in Britain use gas for cooking and heating and 40% of electricity is currently generated by gas, this would be a major leap towards cutting emissions − and it could be done in the next 30 years.
It is an important development for all countries striving to reach zero emissions, because replacing gas central heating in homes and offices has always been described as one of the most difficult technical problems to overcome in order to attain a low-carbon future.
If Britain were to replace natural gas with hydrogen in the grid it would be the first country in the world to do so, and the engineers caution that being a pioneer might produce unforeseen teething problems.
“Using hydrogen in the UK’s gas grid for use by homes and businesses … could significantly contribute to the decarbonisation of the UK’s energy sector”
They announce their news in a report by the Institution of Engineering and Technology (IET), using experts from five professional engineering institutions. It was commissioned by the government to assess the engineering risks and uncertainties around using hydrogen in homes, businesses and factories as a low-carbon fuel.
The snag about the report for environmentalists is that the engineers suggest converting existing supplies of natural gas into hydrogen using a process called gas reforming, which effectively strips the carbon out of it.
The problem with this technology is that the carbon would then have to be stored and used as a product, a technique that has yet to be properly developed on a large scale.
The report’s authors say this is cheaper than the alternative method of making hydrogen from renewable energy. That involves passing an electric current through water, known as electrolysis. When hydrogen is produced this way and burned it combines with oxygen to produce pure water and no carbon; so from an environmental point of view it is far cleaner.
High volumes needed
The engineers say electrolysis is considerably more expensive for producing the large volumes of hydrogen required to feed the entire national gas grid. However, many companies producing excess electrical power from offshore wind farms and tidal power are investing in plants to make hydrogen this way, so the process is already getting cheaper.
In order to use hydrogen rather than natural gas in the grid the engineers say that existing iron gas mains would need to be replaced by hydrogen-safe polyethylene pipes by 2030, a process that has already begun.
Existing gas boilers in homes would also have to be replaced with “hydrogen-ready” appliances. The report says that could be done at little extra cost to consumers because boilers are replaced every 10 to 15 years, so by the time the hydrogen was flowing the boilers would be in place.
Lead author Dr Robert Sansom of the IET’s energy policy panel said: “We are now in a position to seriously consider the viability of using hydrogen in the UK’s gas grid for use by homes and businesses, which could significantly contribute to the decarbonisation of the UK’s energy sector.
Lack of experience
“Hydrogen has not been deployed at scale anywhere in the world and so any proposal will need to compensate for this lack of experience. Our report identifies key risks and uncertainties such as ensuring that we understand the impact on the public from a transition to hydrogen and can minimise any disruption that arises.
“We know hydrogen produces no carbon emissions when burned, but it is also important to fully investigate and understand the overall environmental impact a switch to hydrogen is likely to make.
“It is ambitious. To make a significant contribution to meeting the UK’s 2050 carbon reduction target the transition to hydrogen would need to be implemented over the next 30 years. This may seem a long time but in terms of the infrastructure required and the millions of homes and businesses affected it is relatively short.
“Action is required now, and we hope that our findings and subsequent recommendations can make a significant contribution to advancing the decarbonisation of the UK.” − Climate News Network
