Those who use solar panels and really want to disconnect from the grid must be able to generate energy even without the sun, and keep what is not needed. This is usually done with a domestic lithium battery - Tesla's Powerwall 2 is one example.
Lavo's storage system is called Green Energy Storage. It measures 1.68mx 1.24mx 40cm (66 x 49 x 15,7in) and weighs a whopping 324kg (714lbs). It is very unlikely, let's put it this way, that thieves will take away this domestic hydrogen battery.
How does the hydrogen storage system work?
There is not too much to do. It connects to a solar inverter (must be a hybrid) and to the water supply (via a purifier), and stops.
The household hydrogen battery uses excess solar energy to electrolyze water, releasing oxygen and storing the hydrogen in a patented metal "sponge" hydride at a pressure of 30 bar, or 435 psi.
It conserves about 40 kilowatt hours of energy, three times more than the current Powerwall 2, the Tesla storage system: enough to run an average home for two days. It can not rain forever!
When this energy is needed, the Lavo storage system uses a fuel cell to supply power to the home, adding a small 5 kWh lithium buffer battery for an instant response. There is Wi-Fi connectivity and a phone app for monitoring and control, and companies with higher energy needs can run several in parallel. You can put a domestic hydrogen battery next to each other, and form a small "intelligent virtual power plant".
Currently, it has been said, this system conserves triple the energy compared to a Tesla Powerwall 2 storage system. However, it costs more than triple (we are about 25.000 euros). When the company distributes this domestic hydrogen battery internationally, it says, the price is expected to drop below 20.000 euros. Let's talk about the last quarter of 2022.
Advantages of the Lavo storage system compared to Tesla's Powerwall 2?
First of all, the duration: compared to a lithium storage system, the hydrogen one it could reach 30 years of life (against, perhaps, 15 years). The most important point, however, is that there would be no toxic substances to dispose of. All nice, right? Of course. I'll also show you the Lavo commercial, if your heart holds up for so much marketing. After the video, continue as we do a little reality check.
And the disadvantages?
Safety first: it is certainly the subject of debate. Lavo says an eventual leak dissipates so quickly that there is little chance of fire or explosion. He says that hydrogen is "inherently no more dangerous than other conventional fuels such as gasoline or natural gas". I read all these beautiful things, but I fear the same: in the "rare case" that a fire reaches this plant, what happens? A hot topic, or even an explosive one.
Then there is the efficiency. Batteries store and release energy with minimal losses. With a domestic lithium storage system, more than 90% will be recovered for every kilowatt hour generated by solar panels on a roof. But the process of generating hydrogen by electrolysis with a proton exchange membrane is efficient only 80% approximately. With a domestic hydrogen battery today you immediately lose 20% of the solar energy collected. In the other direction, then, to convert hydrogen back into energy you lose about half of what you have stored. A bloodbath.
In summary: it does not take more energy just to "fill it". When you recover energy, the 40 kWh hydrogen storage system is practically equivalent to a 20 kWh lithium household system.
As a final blow, the maximum continuous power of the system is 5 kW, presumably limited by the efficiency of the fuel cell. There are single split system air conditioning systems that draw more than 7 kW and are not particularly uncommon. 5 kW of continuous power will be a problem; you will need to keep the connection to the network active, there are no Saints.
We give time to time
The problems seem more numerous than the advantages, but we are at the beginning. It's not hard to imagine that sooner or later a hydrogen storage system will make sense at some point along the track.