Whatever the final outcome may be, industry watchers now largely agree that there are two realms where costs must come down for carbon-free hydrogen to advance. The cost of renewable energy, already the object of remarkable reductions in the past decade, must continue to fall. And the cost of water electrolysis for hydrogen production, encompassing the basic hardware of green hydrogen, the electrolyser, must follow a similar path downward.Oilprice
Many see both poised to happen. In fact, the two are integrally related, with operating expense and capital cost factoring into the total cost of electrolyser operation. The decline of renewable power prices is expected to continue, with accelerated deployment of renewables into grids. But capital costs must come down as well, with electrolysis equipment being manufactured more quickly and less expensively.
The Two Major Obstacles To A Hydrogen Revolution
Alan Mammoser
Hydrogen’s efficiency problem
ReplyDeleteThe reason why hydrogen is inefficient is because the energy must move from wire to gas to wire in order to power a car. This is sometimes called the energy vector transition.
Let’s take 100 watts of electricity produced by a renewable source such as a wind turbine. To power an FCEV, that energy has to be converted into hydrogen, possibly by passing it through water (the electrolysis process). This is around 75% energy-efficient, so around one-quarter of the electricity is automatically lost.
The hydrogen produced has to be compressed, chilled and transported to the hydrogen station, a process that is around 90% efficient. Once inside the vehicle, the hydrogen needs converted into electricity, which is 60% efficient. Finally the electricity used in the motor to move the vehicle is is around 95% efficient. Put together, only 38% of the original electricity – 38 watts out of 100 – are used.
With electric vehicles, the energy runs on wires all the way from the source to the car. The same 100 watts of power from the same turbine loses about 5% of efficiency in this journey through the grid (in the case of hydrogen, I’m assuming the conversion takes place onsite at the wind farm).
You lose a further 10% of energy from charging and discharging the lithium-ion battery, plus another 5% from using the electricity to make the vehicle move. So you are down to 80 watts – as shown in the figure opposite.
In other words, the hydrogen fuel cell requires double the amount of energy. To quote BMW: “The overall efficiency in the power-to-vehicle-drive energy chain is therefore only half the level of [an electric vehicle].”
The source below shows the comparison in a visual form:
source: Hydrogen cars won’t overtake electric vehicles because they’re hampered by the laws of science
This YouTube video covers the same idea:
The Truth about Hydrogen
Fossil fuels aren't going away anytime soon; renewables are coming online; and hydrogen is nowhere.
ReplyDeletehttps://www.energy.gov/ne/articles/3-advanced-reactor-systems-watch-2030
ReplyDeleteIn the beginning was the Word, and the Word was with God, and the Word was God. --John 1:1
ReplyDeleteIn the beginning was Hydrogen, and Hydrogen was with God, and Hydrogen was God -- lastgreek