Hydrogen Fuel Cells - are they our future?

Hello and welcome to Just Have a Think. When I was a kid back in the 70s and early 80s, a magical new device came on the market that allowed us to record programs off of the television onto a thing called video. It was a bit like the ordinary cassette tapes that were used to take the top 10 off of the radio every Sunday, but the video version actually recorded pictures as well as sound. It was amazing! These devices were known as VCRs or video cassette recorders and there were two technologies, one called VHS and one called Betamax. Betamax was actually the better technology which was used by all the television networks, but the makers of VHS got their sales and marketing strategy much better focused and as a result VHS became the domestic industry standard. Similar technological battles have been going on ever since. Apple versus Microsoft, Yahoo versus Google, Apple versus Android, you get the idea. Now in the world of electric vehicles most of us know about lithium-ion batteries which are currently the de facto industry standard, but hydrogen fuel cells have been around for a very long time and solid-state batteries are also being developed as an alternative solution to powering our vehicles. So have we got yet another battle for market supremacy on our hands? We'll have a look at solid-state batteries in the next program, but this week we're going to focus on hydrogen fuel cells. On the face of it hydrogen, as the most abundant element in the universe, seems like an obvious choice. It's packed full of energy. In compressed form it contains 40,000 watt hours per kilogram compared to only 278 watt hours per kilogram that the best current lithium-ion batteries provide. The trouble is hydrogen likes to combine with other elements like oxygen and carbon which is why we only usually find it locked up in things like water and hydrocarbons. So to get hydrogen on its own you have to use a bunch of energy to split it away from its elemental partners. Now there's two main ways to do this, electrolysis or steam reforming. Steam reforming is used widely in industrial hydrogen production, particularly in the United States. Steam is added to methane to give off carbon monoxide and hydrogen. It turns out there's actually more energy available in the methane gas at the start of the process than there is in the hydrogen that you get out at the end. Plus the whole process produces a load of pollution and greenhouse gas. Electrolysis is the second method of extracting hydrogen. This uses an electric current between a cathode and an anode like we used in chemistry at school to separate hydrogen from water. Now you can power this process with renewable technologies to provide the electricity so that's much better than steam reforming. But you lose about 30% of the energy you put into the reaction so it's still a lot less efficient than the 99% charging efficiency of a lithium-ion battery. Then you have the problem of density. Hydrogen isn't dense as a gas or liquid so you have to either pressurize it or cool it down to extremely low temperatures in order to get a decent amount of energy out of a reasonably compact amount of space, which of course is what you need if you want to power a car with it. Otherwise we'd all be driving around in large buses with only two passenger seats at the front and a 50 foot long hydrogen fuel cell in the back. So you've got your hydrogen split away from where it really wants to be and compressed into a form that takes up as little space as possible. Now you need to get it to the place where the car driver can put it in their vehicle. Now you could build a small hydrogen production facility at every filling station but that's really expensive and the smaller the scale of production the greater the inefficiency. So alternatively you build a big production facility with better efficiency but accept that you need to transport the fuel to the end user via a fleet of delivery vehicles or a network of pipelines with energy losses of anything between 10% and 40%. So by the time you get to the end user you've lost between 30 and 60% of the energy compared to only about 6% of the energy with a lithium-ion battery assuming it's been charged up from renewable energy sources which of course is not always the case today. Anyway we've now arrived at the end user point where the driver either has a battery powered car or a hydrogen fuel cell powered car. So how do the respective onboard systems compare in terms of efficiency? Well the hydrogen fuel cell works a bit like electrolysis in reverse. So you've got an anode and a cathode just like in electrolysis and the hydrogen is sent to the anode where a catalyst which is usually a thin coat of platinum reacts with the hydrogen and splits off its protons and electrons both of which then want to move towards the cathode on the other side of the fuel cell to react with oxygen. But a clever membrane sits between the two electrodes which only allows the protons to go directly from one side to the other. The electrons are diverted out and around an external circuit on their way to the cathode and it's this movement that causes an electric current that drives the motors that turns the wheels of the vehicle. One of the many advantages that both fuel cell and battery powered electric motors have over internal combustion engines is that they operate at an efficiency of about 90 to 95 percent compared to the absolutely dreadful 20 to 30 percent of gasoline and diesel engines which use most of their energy getting super hot. And of course both battery and hydrogen fuel vehicles have zero emissions at the point of use, the byproduct of hydrogen fuel cells being pure water. So if you take everything into account and add up all the inefficiencies at every stage of the overall processes of producing power from hydrogen fuel cells and lithium-ion batteries, you end up with a figure of about 35 percent for hydrogen fuel cells compared to 75 percent for lithium-ion batteries. And if you really want to blow your mind with the in-depth science of hydrogen as a fuel source then I can highly recommend you click on this link up here to go and have a look at the superb explanation from the folks at the Real Engineering YouTube channel. Anyway the net result of all this is that at the moment the cost per mile for hydrogen fuel cell vehicles is about eight times higher than the cost per mile of a battery powered vehicle. The biggest problem that hydrogen fuel cells may well face though is the same one that Betamax faced against VHS back in the 80s. The infrastructure for battery powered electric vehicles is already pretty well established and rapidly becoming almost as ubiquitous as traditional fossil fuel filling stations. On top of that charging times are being reduced very rapidly with high powered chargers to the point where in some cases 100 miles of range can already be added in only 10 minutes. And then of course you've got master marketing geniuses like Elon Musk, the owner of Tesla motor cars, who's already made battery powered electric vehicles into a very desirable commodity and who's publicly declared hydrogen fuel cell technology to be very silly indeed. Despite this Japan is throwing its weight behind hydrogen technology with a target of 40,000 fuel cell electric vehicles or FCEVs on their roads by the end of 2020, rising to 800,000 by 2030. And that means Japanese car makers are having to respond to the challenge. Toyota's main offering is the Mirai, a decent looking family hatchback with about 300 miles of range, a top speed of 111 miles an hour and a 0-60 time of just under 10 seconds. But my goodness it's expensive. Starting price is currently £65,000 in the UK. Alternatively you can lease one for about £750 a month. Now in reality Toyota only really expect to sell this model into the fleet market at the moment in the hope of growing the refueling infrastructure and number of vehicles to a point where economies of scale kick in to make the price more attainable to the average private vehicle owner. Honda has the clarity. It is pretty ugly but nevertheless a contender in this fledgling FCEV market. It's got a better range than the Mirai at just over 400 miles. It'll hit 60 miles an hour in about nine seconds and carry on to about 100 miles an hour where permitted. The price tag for the Clarity starts at about £53,000. Cheaper than the Mirai but still a bit eye-watering. And then there's Hyundai, although of course they're actually South Korean not Japanese. Hyundai have also ventured into hydrogen power with this very smart looking Nexo model, the best looking of the current crop in my opinion. This option gives you the best range of the three cars at about 500 miles, a 0-60 time of about nine seconds or so and a top speed of 111 miles an hour. Still right up there at the pricey end of the market though at £55,000 in the UK. The real limitation that hydrogen fuel cells are facing at the moment though is refueling. Here's the zap map that we looked at in the last program showing all the battery EV charging stations and here's all the currently available hydrogen refueling locations in the UK. So just at the moment it's no contest. Where hydrogen power really does appear to have a bright future though is in the heavier industries and in the fleet markets. For example the provision of fuel cells for fleet vehicles like buses, coaches and delivery lorries and vans, all of which start and finish at a single depot and which can therefore all be refueled at the same place, which vastly reduces the infrastructure costs. The same goes for maritime power. This is a ferry up in Orkney that Robert Llewellyn went to look at in 2017, entirely powered by hydrogen, which is a by-product of the amount of electricity their wind and wave power produces, which is way more than the island can use. You can click on the link at the top of the screen to see the fully charged program that Robert made looking at the way Orkney and other islands are utilizing the free energy that wind and wave provide for them up there. Germany this week launched the world's first hydrogen powered train which can travel up to a thousand kilometers or 620 miles at speeds of up to 90 miles an hour on a single tank of hydrogen. And even air travel may also be a viable candidate for a switch from the current kerosene to hydrogen fuel cells, this four-seater plane uses lithium-ion batteries for extra power at takeoff but then it's entirely powered by hydrogen fuel cells and it's got a range of 900 miles at about 124 miles an hour. And even the mighty Boeing are testing hydrogen fuel cells as a potential source of power for future models, so watch this space folks. Ultimately though for us car driving road users it'll most likely be the level of market penetration rather than any comparative technical superiority that determines the winner in this battle for consumer EV power domination. That's it for now though, please do subscribe to the channel if you enjoy watching the programs, it's completely free to do that but it does raise the profile of the channel on the YouTube search algorithm thingy bobs. And don't forget to hit the notification bell to get news of whenever a new program comes out and you can do that by clicking on the link over here somewhere that's just appearing. As always thanks very much for watching, have a great week and remember to just have a think! See you next time!