How to Promote the Hydrogen Economy Hoax

The report on the home electrolysis station is interesting. The cost of $250,000 dollars is excessive, but I think this is the result of them anticipating sales counted on the fingers of one hand. I would expect at least one order of magnitude reduction in this if not nearer two if they became popular.

It is more interesting to look at how much electricity it needs to run one so as to provide enough hydrogen to run a car. Working on an average figure of 40 miles a day, one might consider that providing a kilogram a day sufficient. This will run a Mirai for about 60 miles, so on average it will provide more than is needed.

Commercial electrolysers require about 50 kWh to turn 9 kg of water into 1kg of hydrogen and 8kg of oxygen. There seems no good reason to suppose this system will be very different from this. So if this power comes from your solar roof, and we estimate an 8 hour day, we need the roof to supply on average about 40/8 = 6kW. A 10 kW system would do this in California, but probably not in the UK where you would require some mains power too in the winter.

Although the whole chain - from sunbeams to road miles is grossly inefficient - I don't suppose this would particularly concern a driver who is driving for nothing, once he's paid for the kit to do it. If he can pay - say - $10,000 dollars up front and never buy fuel again I suspect he'll do it.

I cannot make any sense of the claim that the hydrogen supply industry is "bumping up against the limits of the laws of thermodynamics". I expect it is a complicated way of saying hydrogen requires a lot of energy to produce. This is undisputed of course, but in terms of cost, the fact that the price of renewable electricity is falling fast, and the supply of it is substantially unlimited, there seems to be very little to bump up against, and we can supply what we need without tangling with any laws of thermodynamics. Generally, these laws don't stop you from doing much. They simply tell you the minimum amount of energy you will need to do it.

 

If we can't figure out how to install charging stations, how will we figure out how to install hydrogen filling stations?

By the way, in the UK, they are installing charging plugs at every street light pole, at a very low cost.



I am installing a 10.1kW solar PV system on my house that will supply an average of about 35kWh / day. It will pay for itself in just over 5 years, and that is almost SIX TIMES more energy than the hydrogen system you are talking about. A battery storage system for the house will cost a fraction, or the battery in the car can be used for this - along with millions of other EV's. This can vastly improve the entire grid.

 

You can't put in charging stations easily because to do so at an adequate level would melt the grid! Hydrogen charging units take nothing by comparison and you need fewer.

I can assure you that they are NOT installing charging plugs at every lamp post. I live there and have seen none. They may have done it with a few dozen in London but nowhere else. Why bother? The demand is miniscule. Most local councils have far more pressing matters on their minds!

If you are installing a solar roof, then you are well placed to use hydrogen or batteries. But you don't need me to remind you that you cannot store enough energy from it during the day if you are using your car. You have to store it separately and that means a battery as big as the car's. If you have two EVs, then you'll need TWO batteries as big as the cars' to store enough to charge them from it at night. Good luck with it anyway.

 

BEV's use at most ONE THIRD the energy that fuel cell electric cars do - so how can you say that BEV's would harm the grid, but FCEV's would not?

They CAN install charging plugs at each light pole, for a relatively tiny cost. So, BEV's are easy to do. And there are FAR more BEV's than FCEV's, so BEV's will grow quickly, and FCEV's are dead on arrival.

Making hydrogen at home would take at least THREE TIMES more energy than charging an BEV. And home batteries cost far less.

 

Because - in a filling station - BEVs have to be supplied with energy at high power rates from the grid which it cannot stand without huge enhancements. Hydrogen for filling stations can be made in refineries or electrolysis plants co-located with wind or solar farms and transported to the filling station

They CAN install charging plugs at each light pole, for a relatively tiny cost. So, BEV's are easy to do. And there are FAR more BEV's than FCEV's, so BEV's will grow quickly, and FCEV's are dead on arrival.

 

Ok, so:

Close enough.

Between the higher purchase price and refueling, eventually dollars will hit them with a clue by four.

Bob Wilson

 

Because BEVs have to be fed with huge amounts of power at filling stations so ALL the energy comes via the grid. Hydrogen will be produced at refineries (initially) and then at electrolysis plants co-located with wind or solar farms and transported to filling stations by road tanker. The energy doesn't travel via the grid, but by road.

But they won't. There is no demand for them so why should they bother. Also they are unlikely to supply much power as lamp-post supplies are generally low current.

It ain't necessarily so. The growth rate of plug-ins is around 25% a year. This is due to at best a half dozen or so models. Exclude those and there is almost no growth. The Mirai seems to be growing consistently at six times that (150% a year) and already outsells two-thirds of the plug-ins listed in the EVblog. Given that they are expensive and can be sold only in California because you can't get hydrogen anywhere else, that is a fantastic growth rate. Less expensive models are imminent, and we can expect growth to accelerate even more when they arrive.

I have explained time and time again that the amount of electricity used is not of great importance if you do not have to pay for it. (The sun makes no charge for shining.)

Home batteries are generally far too small to supply a car. The Tesla Powerwall can store (at best) 13.5kWh A Tesla Car Battery requires 85kWh to charge. If you intend to store power in a battery during the day to fully recharge your car at night you will need an 85kWh battery which Tesla will sell you for $12,000. You'll have to install it yourself I imagine - it is designed for a car, not as a buffer store - and do the necessary adaptation to it to work as required. In fact you'll need a bit more because round-trip efficiency is only 90% at best (You get - at best - only 90% of the energy you put into the battery back out again)

But why decide now? You are installing a solar roof and are happy using it for your BEV which is fine. If hydrogen ever becomes more popular as I suspect it will, you can always switch over to making your own hydrogen if you decide to change. It isn't - as far as you or I are concerned - a competition. Both of us can choose what suits us best at any time and change our minds if we want to. If something changed dramatically to make BEV's better I'd happily buy one.

At this point in time it seems to me to be unlikely, but I'm not going to care much if I'm wrong.

 

I don't really understand the point you're making, but a filling station can be expected to last maybe 10 years, so its construction cost is $300,000 dollars a year which makes it quite viable. I imagine if one is building a filling station, it would include conventional pumps as well as hydrogen ones, so the cost doesn't ALL have to be borne by the hydrogen customers.

If he borrows the $3 million from a bank, he will pay perhaps 2% on it in interest, $60,000 a year or $165 a day. This doesn't seem unmanageable for a filling station with a shop included as seems to be the case in the pics.

 

Huh? We are talking about Level 2 charging stations.

 

You have to pay for the solar PV system to supply hydrogen, and if you need 3X as much energy, then the system will cost 3X as much, and take 3X as much space.

 

I don't know anything about 'Levels' but I am assuming Tesla's 'Superchargers' which are claimed to charge at 125kW. You will note that the bigger and better the batteries are, the more charging at this level is required to recharge in a reasonable time. As I've pointed out elsewhere, to provide the same level of service as is now provided by a single petrol or diesel pump would require eight of these, taking a total of one MegaWatt. If you charge at a lower rate - say half the 125kW, you need 16 such points to do what a single petrol or diesel pump does. The 16 would still take a total of one megaWatt though.

It is possible to express the energy delivering capabilities of a petrol or diesel pump as a power level I can put a MegWatt hour of energy into a car in two minutes, which corresponds to a power level of 30 MegaWatts. If this were done, electrically in the same time assuming a perfect one MegaWatt hour car battery that could accept a full charge in two minutes I would need to do it at 30 MegaWatts. That's 30,000 volts at 1,000 Amps and you would not want to be within twenty or thirty feet of that unless you wanted to risk a very painful death!

The relatively small capacity of current batteries has diverted attention from the problems still to come in charging a really fast capacious battery quickly.

You say you are installing a 10kW system which is more than adequate to provide enough hydrogen to run one or even two cars that do the average mileage of 40 miles a day. Basically, you need 50kWh of energy to provide a kg of hydrogen which will run a Mirai for 60 miles. In bright sunlight, your roof will produce a kg of hydrogen in 5 hours. It will probably produce more than you need.

As you have BEVs, I imagine you'll stick with them. Will you store energy from your roof during the day to charge your cars in the evening?

 

Charging stations are classified in three groups: Level 1, Level 2, and Level 3. Simply put, L1 is 120V, L2 is 240V, and L3 is 440-480V DC.

Charging at home, or parked for a period of time only requires L2 charging. Cars are parked most of the time, anyway.

L3 charging is only needed when you are on a long trip.

50kWh is enough to drive an EV about 200 miles. And you don't have to put it directly into the car - you put it into the grid, to offset the electricity you use.

It is quite possible to use the hundreds or thousands or millions of EV's that are plugged in at any given time, to buffer the grid. Put them all together, and we could have an enormous capacity of grid storage.

And there are other very simple ways to have grid storage. One is pumped hydro, and very similarly, a startup in the UK called Gravitricity uses 30 ton weights in a deep shaft into the ground to store excess energy, and then generate electricity when needed.

 

Thanks for the information on levels. I was concentrating on the filling/charging facilities at motorway service stations. These are the UK's fast roads intended for long distances where motorists WOULD wish to refill /recharge. Typically you might have 30 or more pumps in use simultaneously at these stations. I assumed a similar throughput of electrically charged vehicles would be needed, on the basis that it takes eight times as long (40 minutes) to charge a BEV as it does to fill a tank (5 minutes) This assumes Level three charging at 120 kW rate. i.e. to supply the same number of BEVs as ICEs per hour, you would need eight times as many charging points as pumps.

I know proposals have been made for using cars' batteries for grid storage, but I am not sure how well this would work in practice. The more you use a car battery, the more you hasten its death - they are designed to work for so-many charge /discharge cycles, so allowing your car to be used would imply some cost. How many people would accept this? Perhaps they'd be paid something for it? AndI'm not sure if I'd be very pleased if I'd plugged the car in to prepare for a long trip to find that it was not fully charged because it had been used for supporting the grid.

Pumped storage schemes are not cheap. I've visited one built inside a mountain and its scale is impressive. But such schemes rely on Geography. You can't build them everywhere. In my opinion, the most elegant form of energy store utilises pumped heat using a heat engine running an isentropic cycle. These are scaleable, can be built anywhere, and are dirt cheap. This is because most of the system IS dirt - or gravel anyway, held in two insulated tanks - a hot tank and a cold tank. The working fluid is Argon. Energy from the grid is used to heat the gravel in the hot tank and cool the gravel in the cold one. To return the energy, these temperature differences are used to run the heat engine. It has rather better round-trip efficiency than pumped storage and can be easily co-located with cities where the demand is, so reducing transmission losses. You can see a video explaining it here:



The company developing it went bust, but the idea is sound (although the thermodynamics is hard to follow) Their pilot plant, however, is being completed by the University of Newcastle who will - I imagine - soon be publishing papers on its performance. If it meets its design spec. I imagine they will be rolled out across the country in due course. They are much cheaper than battery farms and last indefinitely with regular maintenance.

I would be suspicious of Robert Llewelyn - the man in your video - by the way. He is totally unqualified, technically, being an actor rather than an engineer. He is a well known 'battery head' and seems to be making a living out of promoting BEVs. No reason why he shouldn't, but be aware that he IS a bit biased and avoids mentioning any problems.

 

Robert Llewellyn is reporting facts. Gravitricity will be much lower cost than any other storage system I can think of. And Tesla is showing how much income grid storage can generate. They will pay for themselves in a short period of time.

I find it bizarre that you are criticizing something that you know so little about.

 

As he usually does, he leaves out any of the figures (even rough ones are sufficient to give an idea of whether it's a good idea or not)

The energy involved in raising or lowering weights is easy to calculate It is given by m.g.h where m is the mass, g is the acceleration due to gravity (10 m/sec/sec) and h is the height.

Lifting a 1kg weight by 1 metre needs 10 Joules
Lifting a 30,000 kg weight through (say) a 500 metre shaft needs 500 x 30,000 x 10 Joules or 150 million Joules.

This is a lot of Joules, but a Joule isn't very big. Its a Watt for 1 second. So to convert the Joules to kWhs we need to divide 150 million by 3600 x 1000 = 3.6 million which comes out to ... er... 41kWh This is the theoretical maximum amount of energy this enormous and cumbersome lunacy will store. (Its what you get from your solar roof in 4 hours!) But we are not finished yet! Let's consider what happens to old mine shafts. They fill up with water, particularly if they are deep, so you have to pump them dry. So if you have water leaking in at a rate of - say - one and a quarter cubics metres an hour, you are going to have to lift 30 tonnes of water from the bottom to the top. This will take 41 kWh! (neglecting losses)

And if you start looking at frictional losses in the gearboxes, motors and inverters the round trip efficiency goes through the floor. Periodically, you are going to have to replace the cables too - they don't last forever - and they are not cheap. Plus you have guide rails etc. all sitting in a damp underground environment rusting merrily away so the maintenance costs are going to be mind-boggling.

Nothing Mr Llewellyn said was a lie of course. As you say, he spoke perfect truth, but left out the detail that makes this whole scheme a ridiculous one!

I'm sorry you find my disbelief bizarre, but a simple calculation (which I did in my head in seconds) and a bit of common sense is all you need to dismiss it as nonsense. As I have pointed out, it is Mr Llewellyn who is yapping about something he clearly knows nothing whatever about.

The isentropic pilot plant can store about 6MWh and return it at 1.5MW for four hours and is housed in a small industrial building! I doubt he even knows about it.