It’s the first element on the periodic table, and the most abundant element in the universe – this is the stuff that gets fused together in the heart of every star you can see in the night sky.
You’ve already heard of hydrogen. It’s the first element on the periodic table, and the most abundant element in the universe – this is the stuff that gets fused together in the heart of every star you can see in the night sky. When it knocks about with Oxygen it forms H2O, also known as water.
Recently, hydrogen has been hyped as a miracle silver bullet solution for one of the environmental revolutions most challenging issues – heating. When hydrogen is burned it forms water and generates heat.
Terrific, you might reasonably think. Let’s switch to hydrogen – its green, and clean, and we can use the old natural gas infrastructure to move it about. What a perfect solution. But of course, there is more to it than that.
Firstly, where are you going to get the hydrogen from? There are two main sources. One is to reverse the equation above – running electricity through water to split it up into its constituent parts in a process called electrolysis. This could be done using spare wind or solar power on sunny or windy days, making the fuel completely clean. The second source, unfortunately, is fossil fuels. Methane, the stuff we currently use for heating, is comprised of one carbon and four hydrogen atoms. Usually, when it’s burned you get carbon dioxide and water.
Generating hydrogen instead means you still have a fuel you can burn to make water and heat, but also leaves you with that pesky carbon dioxide. This is ‘grey hydrogen’, but if the CO2 is stored somewhere it cannot make its way into the atmosphere, then it is ‘blue hydrogen’. Since you must put energy in to remove the hydrogen and since storing the carbon also takes energy, blue hydrogen might work out as dirtier and more polluting than coal! You can read more on blue hydrogen by visiting the Science Daily website. There’s other issues with hydrogen too:
- It only has about 1/3 the energy content as methane, so we will need 3 times as much to meet the current gas demand
- Gas meters and appliances would need to be converted to be hydrogen ready
- Some of the existing gas network is made of steel, which may be embrittled by the hydrogen if it is transported at high pressures
- This steel could be replaced with plastic (polyurethane) pipes, but this material is more porous and susceptible to hydrogen leakage
- Hydrogen has many of the same safety risks as natural gas – it is an odourless, colourless gas which burns with an invisible flame. Adding an impurity to allow us to detect it might work, but we’d need to find an alterative one to the odorants used in natural gas, which would not be compatible with hydrogen fuel cells.
Of course, none of these obstacles are insurmountable and hydrogen remains one of the best options available to replace natural gas heating.
HyDeploy which is a pioneering hydrogen energy project designed to help reduce UK CO2 emissions and reach the Government’s net zero target for 2050.Trials are currently underway in Winlaton, Gateshead to test the effect of adding 20% hydrogen to the gas supply which will help us understand these problems better.
But anyone who understands climate change will know that grey or blue hydrogen are simply not viable options if we hope to avoid the more harmful effects of environmental degradation. When it comes to hydrogen, its green or bust.