World-first home hydrogen battery stores 3x the energy of a Powerwall 2

Nod

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Source: https://newatlas.com/energy/lavo-home-hydrogen-battery-storage/
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World-first home hydrogen battery stores 3x the energy of a Powerwall 2
By Loz Blain
January 22, 2021
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The Lavo home hydrogen battery is not a battery, it's an electrolysis system, hydrogen storage array and fuel cell power system rolled into one attractive cabinet
The Lavo home hydrogen battery is not a battery, it's an electrolysis system, hydrogen storage array and fuel cell power system rolled into one attractive cabinetLavo
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To get off the grid with home solar, you need to be able to generate energy when the Sun's out, and store it for when it's not. Normally, people do this with lithium battery systems – Tesla's Powerwall 2 is an example. But Australian company Lavo has built a rather spunky (if chunky) cabinet that can sit on the side of your house and store your excess energy as hydrogen.

The Lavo Green Energy Storage System measures 1,680 x 1,240 x 400 mm (66 x 49 x 15.7 inches) and weighs a meaty 324 kg (714 lb), making it very unlikely to be pocketed by a thief. You connect it to your solar inverter (it has to be a hybrid one) and the mains water (through a purification unit), and sit back as it uses excess energy to electrolyze the water, releasing oxygen and storing the hydrogen in a patented metal hydride "sponge" at a pressure of 30 bar, or 435 psi.

It stores some 40 kilowatt-hours worth of energy, three times as much as Tesla's current Powerwall 2 and enough to run an average home for two days. And when that energy is needed, it uses a fuel cell to deliver energy into the home, adding a small 5-kWh lithium buffer battery for instantaneous response. There's Wi-Fi connectivity, and a phone app for monitoring and control, and businesses with higher power needs can run several in parallel to form an "intelligent virtual power plant."
There are plenty of negatives to this technology, but it is still early days.
 

Nod

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How is it worse? Well, the safety aspect is certainly open to debate. Lavo says a leak will rise and disperse so quickly that there's little chance of a fire or explosion, and that hydrogen is "inherently no more dangerous than other conventional fuels such as gasoline or natural gas," but it's fair to say it could really get a party started in the rare event that a house fire managed to reach it.

Then there's the efficiency. Batteries store and release energy with minimal losses; for every kilowatt-hour your rooftop array generates and sticks into a battery, you'll get back more than 90 percent of it. But the process of generating hydrogen by electrolysis using a proton exchange membrane is only about 80 percent efficient, so you lose 20 percent straight away. And at the other end, you'll lose somewhere around half of what you've got stored in the process of converting the hydrogen back into energy through a fuel cell.

...

And the final joy killer is the system's maximum continuous power output of 5 kW, limited presumably by the throughput of the fuel cell. There are single split-system air-con systems out there that draw more than 7 kW, and they're not particularly extravagant ones. 5 kW of continuous power output is going to be an issue; you'll need to keep your grid connection active
 

wingnut771

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True, and petrol is also pretty explosive
In petrol's case the vapour is heavier than air so collects on the ground so more chance of a boom.

They also seem to have a new way of storing the hydrogen in recyclable metal spongy thing.
 

Tacet

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Hydrogen batteries have been around for many years. Previously they were aimed more at industrial use, though, such as telecoms. Interest in them seemed to have grown much less when lithium prices started becoming more competitive.

My main concern with them would be reliability - there's much more there to break than in a lithium battery. That's already the drawback of lithium - you have a layer of electronics between the cells and the load. The life expectancy of the lithium cells themselves is pretty high, but the life expectancy of the battery itself is usually limited by the life expectancy of the output capacitor that sees the ripple from the inverter.
 
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