I notice there is no mention of the efficiency of the system - how much of the energy going into the making of H2 compared with how much is recovered. That's a telling figure for any energy storage system. Since the author left that out, I must guess the figure isn't very good.
A side issue: "around 441 kWh". Haurrrph! The adjective "around" means "don't pay attention to more than one significant digit".
I'd be curious to know how much the kWh ends up costing to a thermal power plant.
I'm sure it's a pretty expensive setup but I like the idea of community solar + storage especially for areas that might not have reliable grid power.
I also think Lithium Ion batteries have now passed deep cycle lead acid as the overall cheaper option for nightly use. Deep cycle lead acid banks can't be discharged under 50% without greatly reducing the total number of cycles and Lithium Ion batteries support several more cycles even if discharged much more deeply (~80%). This is in addition to being about 3x the density (and nearly 6x if counting the need to double deep cycle lead acid capacity).
The battery banks are 2,000 Ah each. There are 2 but 4,000 Ah of storage is needed for 2,000 Ah of capacity because its lead acid. Assuming 12 volts that's basically 24 KwH of useful battery storage.
The Tesla Powerwall packs are $3500/10KwH and 3 of them would take up far less space than all of their lead acid banks.
From the photos it looks like the 120 kWh hydrogen system also offers far better energy density than the lead acid battery banks which is interesting too. Hydrogen offers lower total efficiency than batteries because of high losses through electrolysis but you could compensate for it by throwing in extra panels.
I don't know how much maintenance is involved with the hydrogen system but that's part of what's learned through experiments like this. For a lot of people a lower maintenance system that requires additional panels might be more suitable that a room for of lead acid batteries that have to be regularly topped off and replaced every few years.
Also, I found a lead acid vs lithium ion comparison article here that has some useful data: http://www.altenergymag.com/content.php?post_type=1884
The article is from 2012 and lithium ion is now about half as expensive.
At first blush it doesn't make sense. The systems are sized at 28kW per family which is about 6X the size a net zero single family home should need. The round-trip efficiency (make H2 then convert H2 to elec) is not 100%, batteries are. H2 leaks really, really bad! Fuel cells create waste heat as a byproduct of making electricity out of H2, why the thermal hot water system, in Thailand? What about a car? With 28kW of PV you could power a luxury home off-grid and run two Teslas without fuel cells and no Hindenburg Effect to worry about.
This won't be the first home int eh world to store solar power using hydrogen. North America has a couple of them. The first that I know of was built in 2006 in New Jersey. A second was completed this year as a way to show commercialization is now possible. http://www.hydrogenhouseproject.org/the-first-consumer-hydrogen-house.html
As long as scientists keep chipping away at the problems of energy we stand a chance of surviving future warming. This is one answer among many being tried and every small discovery adds up.
Raven Bo
Very inefficient and stupid. Instead it is better to store as salt water flow battery.... Or just ionized water.
Hey Stu,
Nothing really new here.
You writing doesn't take into account 2 major flaws that would drive the cost down, improve reliability, improve the environment (big time).
The 2 major flaws will be addressed by in US technology research.
Proof has been done and prototype valuated concepts.
But still, you are on the right track for energy and all technology that can get us off hydrocarbons will be welcome.

Yeah this project seems to lack luster in energy conservation. I think 3 pane argon filled windows are a lot better than 2 pane because once the argon leaks out of the 3 pane still has a little bit better than 2 pane filled and if you only have 2 pane you got to replace them every 4-6 years i think.
And that's what I don't like a lot of this junk, PV panels are decent but once you factor in costs of battery and replacement and all the heavy metals and chemicals associated with their production you might as well get a good geothermal unit, solar hot water heater and tap into the grid for the remaining. My dad pays about $35 bucks for utils on a 5k square foot home.