The UK authorities sees the longer term in low carbon fuels – however what’s the actuality? – Watts with that?
Tom Baxter, University of Aberdeen
The UK’s long-awaited hydrogen strategy set out the government’s plans for “a world-leading hydrogen economy” that would generate £ 900 million ($ 1.2 million) and create over 9,000 jobs by 2030, “potentially at 100,000 jobs and £ 13 billion by 2050 ”.
The strategy document argues that hydrogen could be used instead of fossil fuels in households and industries that are currently responsible for significant CO₂ emissions, such as chemical manufacturing and heavy haulage, including the delivery of goods by ship, truck and rail. The government also envisages that many of the new jobs that produce and use “low carbon hydrogen” will benefit “British companies and workers in our industrial core countries”.
At first glance, this vision of a low-carbon future sounds like good news in some of the hardest-to-decarbonise niches in the economy. But is it? And are there other options to deliver net zero that are better for the public?
Let’s examine some of the claims.
A heated debate
The government favors what is known as a “two-pronged approach,” which means that both blue and green hydrogen are used to phase out fossil fuels. Blue hydrogen is made from natural gas – a fossil fuel that currently provides most of the UK’s water and space heating – but the CO₂ that would normally be emitted is captured and stored underground.
Read more: Blue hydrogen – what is it and should it replace natural gas?
However, a recent report casts doubt on the green references of blue hydrogen. Research suggested that blue hydrogen is actually 20% worse for the climate than just burning natural gas for heat and electricity due to methane emissions across the supply chain. It does not appear that the government’s strategy recognized these problems or explained how to avoid them.
Green hydrogen is now produced by splitting water molecules with electricity. A lot of energy is lost in the process, so that the costs for hydrogen per kilowatt hour (kWh) are on average higher than the electricity from which it is generated.
Is green hydrogen a better option for UK households than electrifying the heating system with heat pumps in houses? The bills for green hydrogen are likely three to five times higher than this alternative. Because heat pumps take 1 kWh of electricity and convert it into around 3 kWh of heat, while green hydrogen requires 1 kWh of electricity and converts it into around 0.6 kWh of heat.
The strategy also provides for the natural gas supply for domestic central heating systems to be mixed with 20% blue or green hydrogen. This should help to reduce CO₂ emissions during heating by 7%. Not a bad thing, but are there better ways to use that blue or green hydrogen?
About 1 kg of hydrogen added to the natural gas that supplies a boiler could save 6 kg of CO₂. The UK currently produces around 700,000 tonnes of gray hydrogen per year, which is used to make fertilizer and remove sulfur from oil. This type of hydrogen is also made from natural gas, but unlike blue hydrogen, the CO₂ emissions are not intercepted. For every kg of gray hydrogen produced there are around 9 kg of emissions. Gray hydrogen produces roughly six million tons of CO₂ annually. Wouldn’t it be better for the UK to use this blue or green hydrogen to replace current gray hydrogen production than to use it less effectively in blends with natural gas?
The strategy claims that hydrogen could provide between 20 and 35% of UK energy by 2050. This contradicts the Climate Change Committee – an expert body that advises the government on climate policy. In their most recent CO2 budget, which predicts UK progress towards net zero emissions in the 2030s, their main path predicts that around 14% of total energy needs will be met by hydrogen by 2050.
In comparison, the paths modeled by the EU to reach net zero by 2050 range from zero hydrogen consumption to 23%, with an average of around 12%. Even industry forecasts like Shell’s only forecast 2% hydrogen consumption by 2050. The upper range of the UK government’s projected hydrogen consumption in 2050 is, in my opinion, not credible.
Then there are influential groups lobbying for hydrogen in Parliament, like the Hydrogen Taskforce, which represents members with a legitimate interest in the fuel who will generate significant revenue from this strategy. But is what is good for business also good for UK consumers and taxpayers?
The UK government has failed to provide comparative evidence that hydrogen is a preferred net-zero route in many applications. Hydrogen can only be argued precisely by comparing the paths to net zero, taking into account the entire life cycle of hydrogen fuel and quantifying the effects on people, profits and the environment. This evidence is absent from this strategy.
Tom Baxter, Honorary Senior Lecturer in Chemical Engineering, University of Aberdeen
This article was republished by The Conversation under a Creative Commons license. Read the original article.
Comments are closed.