Sourcing Hydrogen Equipment Part 2— Hydrogen Fuel Cell Electrical Generator
In preparation for demonstrating model based solar hydrogen domestic and community system design, accessible by anyone.
Further to part 1 (Linked above), this article focuses on the fuel cell choice made for the example installation.
As warned, it comes from Alibaba which has a bewildering display of hydrogen based equipment. Even more confusing, is that many equipments there seem to be claiming to be things they are not. Giving suppliers the benefit of the doubt, I think this is mostly down to language, rather than any deliberate attempts to deceive.
The few suppliers I have experience of working with in China are honest, good folk, with nothing bad to say about rivals. If they can’t immediately supply exactly what we are looking for, they will literally re-tool to manufacture whatever we want. Hence why they don’t necessarily see the same importance in getting advertised specifications correct, they will make them correct.
All the same I’ve tried to stick with products that look like they have a cut and dried specification where possible.
Concerning Fuel Cells, they are things that require a certain amount of ancillary system support around them, for them to function in their ideal operating modes. We don’t really want to be concerned with that, if it can be helped.
The most convenient form of the fuel cell containing component of our domestic and community solar hydrogen system is a standalone fuel cell based mains electrical power supply. Think of it as like a standard diesel generator, but instead of feeding diesel to it, we feed hydrogen, and it doesn’t make a noise. It has no engine with rotating machine electrical generator, but a fuel cell driving an electrical power inverter.
To understand the thought process that has to go into selection of this unit, it is necessary to include pretty much the whole system, since the fuel cell has to not only supply the power to the microgrid, which powers everything, but also the electrolyser generating the fuel for everything, including the generator. So in a way we have to think of the generator as operating in a kind of permanent bootstrap mode- it needs to stay alive to keep itself alive.
This might seem a little precarious until we realise each of us ourselves operates in this mode, we have to obtain enough energy for ourselves to metabolise our basic adult requirement of 150 or so joules per second (150 Watts), 24/7 to keep ourselves alive.
Hence why we overcompensate, gathering more energy resources around us than we can ever need.
This is the whole point of the object, to get into a position where we have the potential to create as much hydrogen as we possibly can, much more than we need, because the more of it we create, the more we wind back down the temperature. It all comes from energy that would otherwise become heat, if nothing is done with it.
We have to think of this as building the foundations of a business. We do absolutely want to enable all possibilities of expansion, because when money and the economy changes to reflect it, rewarding it by the issue of Kardashev money, this is when we will see the financial benefits from it really take off.
This makes a big difference to how we approach the selection of components.
We have to think of two scenarios, that I would identify as pre and post Kardashev Money
Kardashev Money for Beginners (Skip this part if you already know it)
If you are reading this, I guess its because you want to understand the whys and wherefores of solar hydrogen, and why it is a physical and economic inevitability.
You might be looking to see if the technology of solar hydrogen is cost effective, and be expecting to confirm it one way or the other, by reading the breakdown of a practical solar hydrogen system, in terms of financial costs.
But if you are thinking only in terms of money and capital, omitting energy and where it comes from, it is impossible to understand.
To understand it, you have to understand the difference between mathematically positive and mathematically negative energy (Apologies for the dramatic presentation):
In essence, it is solar indexed stimulus, which has to come to preserve the energy value of money. Without issue of this, money has to progressively come to represent nothing, because issued only as debt, it can only represent extracted energy, and after it starts to be issued as solar stimulus, it will quickly move towards all money being issued as the latter, because why would anyone choose to have debt, if there is no longer any need for it?
I say a lot more about this in various stories. For anyone not “Up to speed”, below is a primer:
To know how to put some numbers on it there is this:
If you don’t understand the above, then there is probably no point in you reading further, because it is this fundamental mathematical change that is happening to the energy available to us, driven by the very real physical forces of nature, which is bringing hydrogen into view as actually a golden element, that we never really understood until now, since we are seeing the so far mostly implicit effects of solar, hydrogen, interchangeably with money that has to be used in conjunction with it, hydrogen is the activator of all the benefits we will get by being solar powered.
When you understand Kardashev Money, then you can see how a money-fuel tree works:
Hydrogen functionally replaces fossil fuels, despite all the efforts seemingly made by the fossil fuels industry throughout the decades, to “Cancel” it. It is not possible to cancel any physical element, far less the most fundamental element, and therefore the one with inrinsically the highest Joules-per-mass energy storage and delivery potential we know.
Recognising and respecting “The one” when we see it, is some very old advice many of us seem to have forgotten, but it’s pretty important, even existentially important, as we are seeing.
Pre-Kardashev Money Installation
The pre-Kardashev Money installation is the foundation system under design here.
The single electrolyser selected looks like a good value for money foundation installation, because it is expandable, rather than because it is cheap.
We work towards maximising the output from this single initial unit, based on having some form of battery backed secondary power supply hooked up to the solar array output, in order to capture the peak power which will happen every time the solar power exceeds the electrolyser capacity.
Like this, the electrolyser is specified using the mean solar hours, rather than the peak solar hours, and the system is in this way designed to save some money in the pre-Kardasheve economic system by the purchase of a moderately specified battery backup, to backup the peak solar power until the electrolyser can use it.
In essence, the hydrogen backed domestic and community system runs by continuously charging hydrogen storage. This then supplies a fuel cell permanently powering the microgrid, from the stored hydrogen. Where fuel cell choice gets a little tricky, is when we start to consider that the electrical power for the electrolyser itself is ultimately powered from the hydrogen it outputs. This is to enable the whole system to be permanently isolated from mains grids after startup, and for the electrolyser to be maintained permanently in a fully working state, which is its ideal scenario. This is how to get maximum output from it.
From the information in operation manuals, electrolysers in general don’t like to be started and stopped much, there is a ramp-up sequence which they have to go through on startup, and if we were trying to just have a single electrolyser operating during sunlight hours, capturing and converting the whole peak power in real time, we would have the inevitable outcome of missing at least part of the ramp up and ramp down hours of sunlight, and most of the time the electrolyser would be idle. We would not be capturing the full capability of energy from the panels like this, and we would require a big enough electrolyser to capture the peak energy in real time delivered by the panels.
But it is important to reserve the battery-less scenario for scalability. This is what stands as the key to the scaleabilty needed for the post-Kardeshev scenario.
The energy output of one Enapter electrolyser as identified in part 1 of this series, outputing 33KWhrs of hydrogen (1kg) every 24 hours looks adequate to supply the average demand of a household. To get that full capability of hydrogen energy from the electrolyser it needs to run on more or less full power, all of the time. Full power requires 2.4KW for 24 hrs, which is 57.6KWhrs, every 24 hrs. To ensure that this can be entirely supplied from the solar array, this power is what we need to set as the minimum average power requirement from the solar array.
Adding a 20% margin to this, to account for other panel associated losses that might arise from time to time (Panel deterioration / dirt accumulation etc), so as to minimise the possibility of undersupply, thus giving us reasonable assurance of safety of supply, gives us a power requirement of 3KW from the panels.
We need to scale this using the average daily hours of sunlight, to size the solar array necessary to deliver this power.
In UK the average daily hours of sunlight is 4.9 hours.
We need to express this as a ratio of the 24 hour day cycle, and use that to scale our panels requirement.
Our panels requirement is 3KW*24/4.9 = 14.7 KW
This number probably does not divide out conveniently to an integer number of panels, so we experiment a little with known standard panel energy ratings, to see what is closest, giving us something close to what is needed, remembering we already have a margin of 20%, added earlier to account for panel deterioration etc, so we have a little leeway.
A common standar panel rating is 800 Watts per panel. 18 of these gives us 14.4 KW, about 2% less than 14.7 KW.
Using this means our safety margin drops by 2% to 18%. This looks like a good enough trade off, an 18% safety margin.
Even with up to two panels lost due to accident or failure, if all else remains working as it should, there is still be enough remaining to supply the hydrogen power needed by the microgrid, until repair can be effected. So the installation should be sustainable indefinitely with little or no loss of supply, with this 18% safety margin.
To identify the mains output fuel cell, it has been necessary to take into consideration the fundamental energy flow all the way through the solar hydrogen chain.
Now we have fully identified the essential input energy to the foundation system, and the system hydrogen driven mains supply, which will in theory operate to maintain all the hydrogen needed to supply the microgrid energy.
The fuel cell based mains power supply selected is the 10KW supply in alibaba, here:
The Specifications for it are given as “Key Attributes” as follows:
We’ve done this in a fully scaleable form, assuming no external restrictions on real estate for future panels.
Expansion of this system at a future date, as will become beneficial when money comes to be issued as solar stimulus, is now just a matter of scaling up the initial system, by adding extra electrolysers, and the extra panels required to drive these, noting that by having the funds to expand electrolyser capacity well in excess of what is required by the microgrid power requirement, the battery backup can be removed.
Until then, the battery backup is required, by the economics of the pre-Kardashev economic system.
The next part of this series will concentrate on the battery backup, again from Alibaba.
Readers should note, the offline DMN model capable of showing this system in numerical simulation is in process, in the background. What you are seeing in these Medium articles are more or less reports on the progress of turning what has been a theoretical model to date, into a practical system implementation model.
As we all know, the devil is in the detail, this is the part that takes real time and effort to sort out. I thank everyone for your patience and understanding when some of these reports are delayed by the need for more work to be spent on some parts.
The fuel cell power supply selection has turned out to involve a lot more effort than expected, since it has forced some consideration of the whole system, with all the practical intricacies, with impacts also on how the system has to address both of the two scenarios, pre and post Kardashev.
In effect, the design of the system just more than doubled in effort.
The good news is that even more work is being given to you for free!
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Update History:
12/11/2023 — Web page updated to direct to 10KW unit (rather than 5KW), and key attributes added.
25/11/2023 link to part 3 added
