My previous blog post “Hydrogen Madness” generated so much controversy that I am forced to clear up a few points before someone starts a riot.(2) I must admit that I have been taken aback by these disagreements. I am used to having people hang on my every word as if it were the Gospel truth. I intend to expand a bit on my hydrogen ideas in the desperate hope of winning back the nearly universal level of hydrogen confidence that I expect from you Blog Buddies.
The Hydrogen I am talking about here is so called “Green Hydrogen”. The idea of Green Hydrogen seems to get people all excited and I can see why. For starters, hydrogen is the most abundant element on earth! If you burn hydrogen, you get absolutely pure water with zero greenhouse gases. What’s not to like? The energy density of hydrogen is about the same as gasoline. Just put hydrogen in your tank and drive away with nothing but a bit of absolutely pure water coming out of the tailpipe. It all sounds good so far. Hydrogen sounds like the perfect fuel. Green Hydrogen will save the planet; or maybe it will not.
If you don’t think Green Hydrogen is great, just ask the New Zealand Hydrogen Association.(3) The NZ Hydrogen Association is a special interest group of NZ businesses who claim to be supported by the Government to develop Green Hydrogen. The fact that they are supported by the Government (i.e. taxpayer) is what’s got me worried. I wouldn’t mind if these fools want to spend their own money trying to save the sunset industries associated with oil and gas, but they plan to do it with taxpayer money and by God they claim to have the New Zealand Government on their side.
So why do I, a clapped out old electrical engineer, think Green Hydrogen is such a bad Idea? Who am I to defy the all knowing New Zealand Hydrogen Association? Well the first problem with Green Hydrogen is getting hold of some actual hydrogen. Yes, hydrogen is indeed the most abundant element on earth but it is mostly tied up in the form of Water H2O. You can’t just pour water through a strainer and filter out all the oxygen. Oh no, the hydrogen and oxygen in water are stuck together like shit to a blanket. You must first add tons of energy to the water to pry the hydrogen and oxygen apart. That is the whole idea of the giant hydrogen plant to replace the aluminum smelter at Tiwai Point.(4) In order to pull the hydrogen away from the oxygen, you use electric power from a primary energy source such as hydroelectricity from Manapouri Hydro generator. This simple process is called electrolysis. So what the hell is wrong with electrolysis? Why is this old fart engineer banging on about it? Well I’m sure you are just dying to know Bolog Buddies, so I am going to tell you.
Green Hydrogen just isn’t green. The New Zealand Hydrogen Association is trying to sell us a great big bag of bullshit. In my previous blog (see reference 2 below) I claimed that end-to-end efficiency of making hydrogen with electrolysis then tuning it back into electricity in a fuel cell was a measly 48%. I should confess here that 48% in almost certainly not correct! My 48% figure was the absolutely best case scenario. According to a report by McKinsey & Co, a more realistic figure is 25%.(4) That’s right, you lose 75% of your original hydroelectric energy by switching from electricity to hydrogen and then back to electricity. But wait, there is more!
Hyundi make a hydrogen car called the Nexo. It holds 6.5 kg of hydrogen and goes a maximum of 611 km. If you could get one, it would cost $NZ 91,000. The Nexo has a curb weight of 4059 lbs. (1841 kg). The Tesla model S with a 100 kWA battery has a curb weight of 4,883 lbs. (2,215kg) and has about the same range. The battery in the Tesla model S weighs 1,056 lbs (479kg). The hydrogen fuel tank of the Nexo is made from carbon fiber so weighs practically nothing. That means that the Tesla’s 479 kg battery is doing the job of 6.5kg of hydrogen.(5) How can that be true? The answer is that the hydrogen has to go through a fuel cell to produce electricity and fuel cells are only 60% efficient at best. At least 40% of the hydrogen energy is being thrown away in the fuel cell. Compare that to a lithium-ion battery with 95% efficiency.
There is a reason why there are no hydrogen cars running around New Zealand roads. Not only is the business of making hydrogen from wind, hydro or sun, inefficient but hydrogen cars are also inefficient. I’m not the only engineer to figure this out. Less than 9,000 hydrogen cars were sold in the US in the past 9 years. Hydrogen cars are dead.(6)
Well then how about hydrogen trucks or buses or boats? Thanks to Auckland Transport, the long suffering taxpayer has fronted up $NZ 1.175 million for a hydrogen bus.(7)
The bus has a range of 400km and carries 74 passengers. God only knows how much the hydrogen to run this bus trial is actually costing the taxpayer. Nobody will say. AT already has 12 electric busses with the same range and passenger capacity as the hydrogen bus. The viability of the whole crazy hydrogen bus idea depends on building a hydrogen factory like Tiwai Point. Hydrogen busses use the same fuel cell technology as hydrogen cars and are guaranteed to be just as inefficient. The hydrogen bus trial is complete madness. Simon Coates, director of Concept Consulting, said converting electricity or gas to power a fleet of hydrogen trucks would take more than three times more energy than using electricity and batteries.(8) This is Hydrogen Madness!
Hydrogen Madness is the result of desperation on the part of a sunset oil and gas industry that refuses to accept that the end is nigh. The New Zealand Hydrogen Association is telling us things that sound really cool but simply are not true.