At the Max-Planck Institute for Terrestrial Microbiology in Margurg, Germany, a research group under the leadership of Professor Tobias Erb is working towards artificial photosynthesis…

Surely natural photosynthesis is good enough, right? Not for human challenges, because the key enzyme that incorporates CO2 into biological molecules, i.e. “fixes” CO2, is too slow!

The enzyme RUBISCO takes CO2 from the atmosphere, and a form of hydrogen from the splitting of water with sunlight, and generates glucose, which is the building block for most other biological molecules in plants. RUBISCO “fixes” around 8 CO2 molecules per second; but Tobias Erb’s group has engineered a version that is ten times as fast! They are also working on building the chains of other enzymes that work after RUBISCO in lant metabolism, producing countless molecules that are extremely useful to us humans: from materials, through fuels, to medicines. Could we soon have artificial metabolic pathways that turn sunlight and CO2 into economically valuable materials other than wood? Quite possibly! One can’t help but be enthsiastic when watching Prof. Erb talk about his research here: https://www.youtube.com/watch?v=CPFscyYRS10

A recent paper from him and his group looks into accelerating another key enzyme in the photosynthesis chain:

_________________________________________________

Can we really create the necessary electricity storage buffer for the world with batteries? Here’s something that will surely make you think again…

The energy storage problem rears its imploring head in many circumstances, and here’s another one. A very recent report presents scenarios for storing electricity in batteries vor various amounts of time to even out some of the natural variations in regenerative electricity generation. Even for a relatively modest storage period of 28 days, the batteries that we would need globally — at current practicable battery technology and chemistry — would massively exceed the amounts of many of the key respective metals that are in Earth’s reserves — yes, even Lithium. Interestingly, even graphite (for battery anodes) would, in this scenario, only be satisfied to 10% by Earth’s reserves… Surely this speaks for the need for technology diversity in energy storage solutions…

From 2024 report available at: https://tupa.gtk.fi/julkaisu/bulletin/bt_416.pdf

_________________________________________________

How much water would a country need, in order to make its primary energy in the form of hydrogen?

I just picked this one up via Linkedin, so I thought I’d have a go at it with the example of Spain given in the question:

Bottom line – well, actually the top line 🙂 with the assumptions made below, the amount of water needed in Spain for the necessary hydrogen per year would be 2.6% of current agricultural use of water in Spain per year. Note, this is based SOLELY on the assumptions and information below: it is not necessarily realistic, but gives some kind of idea…

Here’s a back-of-an-envelope calculation that I’ve just done, assuming the following:

1. We very crudely equate current primary energy consumption in Spain directly 1:1 with equivalent energy from hydrogen. This definitely isn’t 100% accurate, because, for example, hydrogen-fired steel-making uses less MWh per tonne of steel than coal-fired steel making. However, it gives us a reference point from which to refine the calculation.

2. Current annual primary energy consumption in Spain is around 1,600 Terawatts per year (see https://ourworldindata.org/energy/country/spain).

3. The electrolysis reaction is H₂O -> H₂ plus 0.5 O₂

4. Molar masses (molecular „weights“) are H₂O = 18 g/mol ; H₂ = 2 g/mol which means, in terms of mass (weight), we need nine tonnes of water to make one tonne of hydrogen gas.

5. Hydrogen has a gravimetric energy density of 131 MJ/kg (averaged between HHV and LHV, because we don’t know whether we can recuperate the energy of water vapour formation); this is equal to 36 kWh/kg hydrogen gas.

The calculation:

1,600 TWh per year is 1.6 x 10EXP12 kWh per year

Divided by 36 kWh/kg hydrogen gas energy content => 4.4 x10EXP10 kg hydrogen

This equals 44 million tonnes of necessary hydrogen gas.

To make that via electrolysis, the theoretical minimum mass of water is 9 x 44 million tonnes, which = 400 million tonnes of necessary water.

How much are 400 million tonnes of water? – i.e. 400 million cubic meters.

From Statista, I get a value of 15,500 million cubic meters of water used currently in agriculture in Spain per year (see https://www.statista.com/statistics/1218844/irrigation-water-used-agricultural-sector-spain/) . So, 40 divided by 15,500 gives us a relation to current agricultural usage of water, and it equals 2.6%.

Bottom line: with the assumptions made above, the amount of water needed in Spain for the necessary hydrogen per year would be 2.6% of current agricultural use of water in Spain per year.

______________________________________

On the impacts of mineral and ore mining…

2024, January: United Nations predicts serious environmental and social impacts of raw material mining up to 2060…

And see also report in Sustainability & Environment Network 2024.