by Tim Baxter
It took me a way too long to make this hydrogen blending chart today.
It shows the change in CO₂ emissions from mixing a percentage of hydrogen (by volume) in with gas, while producing the same amount of energy.
5% H2 = 2% less CO2
25% H2 = 10% less CO2
50% H2 = 23% less CO2
This is because hydrogen is much less energy dense than gas. Assuming the same pressure a litre of hydrogen produces about 70% less energy than a litre of gas does.
Mixing hydrogen into the fuel means you need to burn more fuel to get the same amount of energy. You really need to mix quite a lot of hydrogen into gas to have a substantial impact on emissions. 70% hydrogen only reduces CO2 by 40%.
Unfortunately, most gas infrastructure can’t work with high (20%+) levels of hydrogen without substantial modifications.
Pure hydrogen would require extraordinary expense while basically every single piece of the gas network – from transmission, to distribution, to end use – is replaced or very significantly retrofitted.
When gas network operators talk crap about piping hydrogen into homes and industries, be aware that they are mostly having you on.
There will be uses for hydrogen in the future. Those uses won’t be as a stand-in for gas.
Apart from a few edge cases, electrification, paired with deep efficiency and smart demand management, backed by the Australian wind and sun, will eat the heart out of coal and gas in the energy sector.
Hydrogen will likely play a big role as a feedstock, including for steel. Don’t let yourself be bullshitted.
Hydrogen is important, but it isn’t everything. We need to get on with solutions that are ready today.
I should add that the chart at the top is a redrawn version of one in this ???? report. It makes way more sense to me the other way around to how these authors drew it. So I replicated it.
hydrogen-for-power-gen-gea34805.pdf
