“You will receive power!”
Hydrogen is the buzz word right now. How is it made and what are the environmental impacts? It’s complicated! From school you will remember that the symbol for Hydrogen is the letter H. The beauty of hydrogen is that when it burns it combines to make H2O, which is water, rather than CO2 which comes from burning fossil fuels.
The big challenge however of hydrogen is how it is produced. It is rarely found as a gas so needs to be separated from other elements. It requires a vast amount of energy, and the question is – where does that energy come from? The different methods that lead to hydrogen begin with the names of different colours.
Hydrogen can be used as a fuel in cars (Fuel cell electric vehicles). The fuel cell takes chemical energy, in the form of hydrogen, and turns it into electricity that can power an electric motor, just like a battery. The advantage over electric cars is that they can be charged in minutes.
Green hydrogen is the only variety produced in a climate neutral manner which means it could be vitally important in our goals of reducing carbon emissions. It is produced by using solar energy or wind energy. Water is split into two hydrogen atoms and one oxygen atom through a process called electrolysis.
Renewables cannot always generate energy at all hours of the day and green hydrogen production could help use the excess generated during peak cycles.
It currently makes up about 0.1% of overall hydrogen production, but this is expected to rise as the cost of renewable energy continues to fall.
Many sectors also now see green hydrogen as the best way of harmonizing the intermittency of renewables – storing excess energy at times of low demand to be fed back into the grid when demand rises – while decarbonizing the chemical, industrial and transportation sectors.
Black, brown and grey hydrogen
Grey Hydrogen is hydrogen produced using fossil fuels such as natural gas. Methane from natural gas is heated, with steam, usually with a catalyst, to produce a mixture of carbon monoxide and hydrogen used in organic synthesis and as a fuel. Unfortunately, this accounts from roughly 95% of the hydrogen produced in the world today.
Even worse than grey hydrogen are black and brown hydrogen. They use black (bituminous) coal or brown (lignite) coal in the process. Emissions of CO2 and carbon monoxide are produced.
Blue hydrogen is also produced from fossil fuels, but the carbon emissions are captured and stored underground through industrial carbon capture and storage (CSS). Although it is called “carbon neutral’, this is not true as about 10-20 percent of the generated carbon cannot be captured.
Currently, clean ‘green’ hydrogen isn’t scaling fast enough to deliver on its potential, in part due to challenges like COVID-19 and lower fossil fuel and CO2 prices.