A major international energy body has warned that efforts to blend hydrogen into mains gas supplies could be costly and impractical, and push up household energy costs for minimal emissions reduction.
The new report from the International Renewable Energy Agency (IRENA) warns that blending hydrogen in mains gas networks is a complicated way of cutting household emissions and would likely cost more than $US500 per tonne of emissions abated.
The findings suggest that the use of hydrogen in residential appliances like stove-tops and water heating would be prohibitively expensive, and electrification could serve as a cheaper path to cutting emissions. While the exact abatement cost would depend both on the cost to produce hydrogen and the prevailing market price for fossil gas, even dramatic reductions in the cost of hydrogen would still likely see the effective abatement cost exceed $US200 per tonne.
“Blending leads to limited CO2 benefits and to a large increase in energy cost,” the IRENA report says. “This translates into a very high cost of mitigating the GHG emissions of natural gas. Given the current production cost for renewable hydrogen, the cost may be above US$500/tCO2 for most gas prices.”
The findings suggest that hydrogen may never be able to play a major role in the decarbonisation of residential energy use, given technical limitations on the amount of hydrogen that can be blended in the mains gas supply and the comparatively higher costs.
Several Australian gas suppliers are currently trialing small volumes of hydrogen blending to demonstrate that existing gas infrastructure can be adapted for zero emissions energy supplies. But critics of such trials have argued that hydrogen blending has minimal potential to cut emissions, and they are largely being undertaken as a way of delaying the phase out of fossil gas use altogether.