Never mind @phb. You didn’t get it. You can’t turn an element into something else, except by nuclear processes.
We do it all the time with no nukes - eating sugar which our body converts to fat, glycogen etc, which I believe has been discussed extensively on this forum! 
You can’t turn an element into another element with chemistry, but clearly you can turn it into “something else”, ie a compound, by combining with other elements, which is what Peter was saying.
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Clearly you didn’t get it either @gordon. Never mind. I shall refrain from nuclear physics and stick to consumer issues.
Sometimes attempted humour falls flat, even with a smiley. It was attempted humour, wasn’t it?
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What’s inside the box. A neat little diagram. It’s appeared in a number of publications around the same time.
An assumption here, the innovation is the type and form of metal hydride used as the storage medium for the hydrogen.
There are also some interesting details in the linked PV Magazine article on progress with rechargable battery cathodes that do not require lithium.
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hmmm, a 60kWh battery is 50% more than the 40kWh I read about for this unit yesterday! It must be expanding!
It does somewhat push the limits of credulity though- 60kWh + electrolyser + H2 storage all in a bar fridge???
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Talking about domestic energy storage by electrolysis of water. Air that is enriched with oxygen makes fires burn faster and hotter and enables combustion of some fuels that do not burn in normal air.
Say the sun is shining and it is in electrolysis mode a byproduct will be pure oxygen which presumably is blown off into the surrounding air. For the size of system postulated what rate will it be generating oxygen and what will that do to the risk of fire near the equipment? What happens to the metal hydride storage in a fire? What effect would this have on the safety of a domestic installation?
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I’ve read the same 60kWh in some of the more generalised reports. It appears for now the proposed commercialised unit is based on the lower 40kWh capacity.
From looking at the specifications of other metal hydride storage products there are limitations with the rate of absorption (Rate of storage of energy/hydrogen). The losses in the conversions (Efficiency) all come out as waste heat.
Some interesting questions.
The nearest comparison may be a domestic gas HW system or LPG storage installation. There are location rules for management of these hazards. A 45kg KPG cylinder may be more of a risk than a hydrogen metal hydride canister holding the equivalent of 2-3kg of hydrogen. The waste O2 would logically require to be mixed safely with free air and vented away from at risk items. (I suspect the rate of oxygen production is quite low. An electrolyser which consumes 320 W produces up to 60lph of hydrogen and just 30lph or 0.5lpm of O2)
Note:
Electrolyzers and fuel cells generate waste heat. There is also an energy transfer in the absorption of hydrogen into the metal hydride (heat energy created) and on release of hydrogen (heat energy absorbed), cooling effect. Generically clever design apparently uses the cooling effect of the desorption of hydrogen from the metal hydride to help cool a connected fuel cell. The amount of heat created will be a consequence of the power ratings of the electrolyser and fuel cell chosen.
How the thermodynamics of the storage unit are managed? One more item to look for when more details are released.
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No @PhilT. Not humour. Just a comment that you cannot change elemental hydrogen into water. Not in this universe anyway. Maybe being very specific, but I did say that I understood the intent of poster, although literally impossible.
We have been discussing hydrogen fuel cells and at different points battery chemistry. All of these function at a molecular level whether individual ions, elements or compounds.
Those contributing have a basic to reasonable level of knowledge of things scientific. We all strive to make the best use of our knowledge. At times some of us use more plain speaking to explain basic concepts.
Perhaps there has been some confusion at the subatomic level. It might be best to stay at a level the average consumer might relate to. There is a learned skill in explaining science. Dr Karl is my gold standard. We can aspire to follow.
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Fine. But when dealing with science, it is always good to stay on the side of basic principles. And that does, unfortunately, involve some specific terminology.
With science, adding oxygen to hydrogen gas through combustion makes water (hydrogen gas is the input along with air/oxygen into a fuel cell - H+ or hydron isn’t what was being discussed). You don’t need nuclear reaction (fusion or fission) to turn one compound into another like hydrogen into water.
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Oh jeez @phb, I rest my case. Terminology. Basic principles. Where do I start.
Hydrogen gas is not a compound, neither is Oxygen gas. You have two elements in a comfy arrangement in a pair in a covalent bond, sharing electrons in their outermost electron shell.
H2 and O2.
Bring them together and add enough energy to break the covalent bonds and they can rearrange into a new arrangement of H2O, which is water. The reaction is exothermic, so energy is released.
Now H2O IS a compound molecule, since it contains more than one type of element.
Neither the Hydrogen or Oxygen atoms are in any way transformed into something else, so talk of nuclear fission or fusion has nothing to do with this reaction.
So you cannot say that you have “turned Hydrogen into water”. Ever. What you can say is that a chemical reaction has occurred, that has produced a new rearrangement of atoms, and some beneficial excess energy, usually heat.
This topic began to highlight tests done on home battery systems for solar installations. It has since become far broader and beyond the original consumer focused report highlighting the state of batteries.
Until there is something to add to the original topic I am temporarily closing this for 2 weeks or if Choice updates their review. When it reopens please keep posts relevant to the topic.
For alternative discussion please start relevant topics.
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This topic was automatically opened after 13 days.
The first mistake in the Solar Quotes article about home battery systems is quite interesting and reinforces many of the comments made in this thread…
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I was looking for Solar Quotes contact details the other day to advise them of the shonky below.
I was under the impression that Solar Quotes would have been a one-man-band but their website lists some 14 staff members.
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Telsa have announced (well maybe not announced but slipped through) a price increase on their Powerwall 2 domestic battery.
This goes against the belief that like Solar PV, that the longer one waits the cheaper they will become. The additional $800 will make home batteries further uneconomic for grid connected systems,
It is also worth watching the video towards the end of what happens when one Li-ion cell is ruptured and the chain reaction/combustion (called thermal runaway) that follows. These are the same type of cells used in most electric vehicles, and rapid ignition fires have been reported in cars where batteries have ruptured.
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I have also witnessed petrol/Fossil Fuels (FF)/alcohol fires in Internal Combustion Engine (ICE) cars that developed very rapidly until the vehicles were consumed and they continue to happen multiple times a day all over the World. They probably for many reasons are not newsworthy in the same way that an alternative energy storage system is. I don’t think there is any truly safe way of storing large amounts of energy that is needed for transport or many other activities/uses. There is always risk, it is knowing the risks and as much as possible mitigating them. Coal, Nuclear, LNG, LPG, Petrol (and the other hydrocarbon products), the power stations, the refineries, the mines and pumping and wells that produce these products have done untold damage to our environment Worldwide, and some of the fires and explosions they have caused have been monumental, they aren’t in any way completely safe and I would go so far as to say they are hazardous to all. In the same way we have safe petrol/FF driven vehicles I think we have safe batteries.
What Tesla do re their pricing is not the be all and end all of battery storage, in general prices go down as tech matures and this trend has started in the renewable sector. The economics of battery storage in the pure monetary sense is not at the same level as other ways of delivering power. But considering that Fossil Fuel has a long head start it isn’t surprising that alternative ways have some way to catch up and they are not supported financially to the same degree that FF processes are. However in terms of providing a cleaner source of energy storage and usage the pure money side is not and should not be the only concern or weighing that should be given.
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