LETI Hydrogen Report

LETI Hydrogen Report

LETI – the London Energy Transformation Initiative – is a network of over 1000 built environment professionals working together as volunteers to put London on the path to a zero carbon future.

LETI has investigated whether using the gas grid to distribute hydrogen gas for heating makes sense.

Hydrogen fuel is often touted as a viable solution to help in meeting UK Net Zero carbon targets. LETI has therefore sought to investigate this further and to examine to what extent hydrogen is likely to be used to accompany decarbonisation of the electricity grid.

LETI has just published its paper on Hydrogen – a decarbonisation route for heat in buildings?

We recommend that you read the brief report. It is well argued with clear illustrations and explains why LETI is sceptical about the practicality, efficiency and economics of burning hydrogen to heat buildings.

For those short on time, you may want to jump to LETI's conclusions:

  • "We have found that the public discourse on hydrogen appears severely unbalanced, with the gas supply industry in particular over-selling ‘green-gas’ to policy makers in order to protect their interests".
  • "When blue hydrogen, supplied via the gas network, is compared to the use of heat pumps there is a stark difference in efficiencies".
  • "It is unlikely that zero carbon hydrogen supplied via a re-purposed gas mains network will be available for the vast majority of buildings, for the foreseeable future".


Efficiency of Hydrogen for heating buildings vs using heat pumps

The diagram below contrasts the limited efficiency of converting natural gas to hydrogen and distributing it through the gas grid for heating (at 58%), with using green electricity to heat homes via air source heat pumps (at 270%).

Hydrogen vs Heat Pumps Efficiency







It is worth noting that this hydrogen-from-gas route will still not yield a zero carbon system – unlike the heat pump route which is 100% zero carbon (and also 100% zero NOx).








A well designed ground source heat pump system will yield a significantly higher efficiency than the air source system illustrated here.
















See Ground Source Heating       See Ground Source Cooling      See Ground Source Energy


Ground Source Heat Pump Association