> The trimetallic NiFeMo electrocatalyst takes the shape of nanometer-sized flakes anchored to a fully carbon-based current collector comprising a nitrogen-doped carbon nanotube network, which in turn is grown on a carbon fiber paper support. This catalyst electrode contains solely Earth-abundant materials, and the carbon fiber support renders it effective despite a low metal content.
I don't know anything about chemistry so I'll have to take their word on the fact that the elements they use are abundant.
The two concerns for area are:
1) The cost of panels to cover the area
2) The cost of the area itself, and the availability of a ton of empty space in a convenient location
If they are using abundant materials, the first is not as much of a concern, compared to photovoltaics. Since they are producing some sort of fuel rather than directly producing electricity, transmission efficiency is not really a concern*. So maybe we could plop a bunch of these things down in some sunny middle-of-nowhere desert.
* I guess is we consider vehicles to transport fuel, which must themselves burn fuel, to in some sort of abstract sense be part of the transmission efficiency, this computation could be pretty complicated.
Carbon, Nitrogen, and Iron are cheap and easy (you’re likely within body length of a large quantity right now). 32% of the earths mass is estimated to be Iron. $1/lb or less in massive quantities.
Nickel and Molybdenum are slightly harder to find, but not by much - nickel makes up 1.8% of the earth by mass and is a reasonably common metal in everyday manufacturing. It’s currently at $3.97/lb spot price at tonne quantities. Moly is in everything from greases to steels, and while typically not used in large bulk quantities alone, is available for such [https://tradingeconomics.com/commodity/molybden] at looks like $23/lb give or take.
So all commonly available elements, albeit (nanotubes) not necessarily in the form desired just yet.
You either put it really far away (increasing transmission losses and right of way issues for the much longer lines), or you put it closer and then have to deal with expensive land or difficult environmental reviews.
It is not AS BIG of an issue as it could be - for instance 30% efficient cells vs 23% efficient cells, the lower efficiency’s cost vs space usually favors the lower efficiency, but it’s still very strong overall.
Plants generally max out the amount of solar radiation they can absorb early in the day, so are not handicapped at all by partial shade. In fact, most benefit from it in numerous ways.
Installed between rows in active farmland, solar reduces water demand by up to 50%, which is a really huge benefit. Reducing heat and evaporation stress improves crop yields. So, a farm could move from barely getting by to solidly profitable by installing solar, even before selling the power. The panels just need to be placed so as not to interfere with driving a tractor between them.
So, no, there is absolutely no shortage of land for solar installations.
Racking and wiring is one of the dominant costs in any solar installation, and a big flat desert is cheaper both to install and maintain than almost every other option by a pretty hefty margin.
Maybe the solar cost efficiency taken alone is reduced, but the system efficiency of the real estate use goes up as does the ownership value for the property owner.