Back to the future

Pause for thought for those convinced that achieving net zero carbon means electric heating will become the norm in all British buildings within the next 15 years. Currently over 80% of UK homes depend on gas for heating and cooking.

For so long as gas produces greenhouse gases like carbon dioxide and methane, its days must be numbered.

But what if gas production could become as it was before North Sea Gas, when town gas was made available to homes that was more than 50% hydrogen, after being derived from coal?

Presently hydrogen is mostly produced for commercial use by extracting it from natural gas, which is carbon intensive. But technically it is equally easy to extract hydrogen from freshwater or seawater using electrolysis − a process that involves passing an electric current through water to obtain hydrogen and oxygen. When the hydrogen is burned it produces only water as waste, and no carbon dioxide.

Several trials are already taking place in the UK with existing gas distribution networks to supply homes with a mixture of up to 20% of hydrogen and natural gas. Others are developing networks that can burn 100% hydrogen.

However, current legislation bans more than 0.1% of hydrogen in the gas network. If either or both of these trials prove successful, the government will have to change legislation to allow such schemes to be rolled out to consumers, thus retaining the gas network of transmission and boilers.

Given the right regulations and market incentives, around 60% of the heat supplied to domestic, commercial and industry consumers could come from hydrogen in the gas network. 

Sales of gas to buildings (its main market) have already dropped by one-third since 2005, thanks to better energy efficiency. It is reckoned that more insulation and modern glazing could easily reduce gas use by a further quarter by 2035. The future may not be quite as electric as many are naively assuming.