One of the nasty secrets of solar power is that the magic depends on some really nasty, toxic materials. PV power is clean and carbon free, but to date the implementation has used dangerous materials that ultimately will need to be recycled and rendered safe. Similarly, methods for solar generation of hydrogen involve nasty (and rare, expensive) materials.
But new materials and processes are on the way, which will detoxify the manufacture and decommissioning of PV units, and hydrogen separation.
This fall, another new technique was reported for creating photo reactive semiconductors, without nasty materials [1]. The new technique creates “quantum rods” which effectively catalyze the reaction to split water to generate hydrogen.
(Long ago, when I was struggling through beginning chemistry, I remember the teacher telling us that “with the right catalyst, anything is possible.”)
I don’t follow the details of the procedures, but the basic point is that its pretty simple, and uses no heavy metals or other extremely toxic materials. The technique manipulates the material to create nano structures that are very efficient at separating hydrogen.
This material could be the basis for efficient solar powered generation of hydrogen for clean power generation.
Cool!
Another alternative are improved “flow batteries”, which are integrated units that harvest solar energy and use it to charge a liquid electrolyte [2]. The charge can then be discharged later.
An integrated flow battery can operate as a solar cell, as a battery, and with the solar charging the battery to store energy for later.
The implementation is complicated to say the least. The game is to balance the costs and properties of the chargers, electrolytes, membranes, and connectors; aiming to get the most energy with the least cost. When it works right, it is pretty much just what you need for 24 hour power supply from the sun.
Unfortunately, this one isn’t quite so non-toxic as we might like (as far as I can tell). In future developments, it will be good to devise lower cost, lower toxicity components for this cool design.
- Dechao Chen, Huayang Zhang, Yunguo Li, Yingping Pang, Zongyou Yin, Hongqi Sun, Lai-Chang Zhang, Shaobin Wang, Martin Saunders, Emily Barker, and Guohua Jia, Spontaneous Formation of Noble- and Heavy-Metal-Free Alloyed Semiconductor Quantum Rods for Efficient Photocatalysis. Advanced Materials, 30 (39):1803351, 2018/09/01 2018. https://doi.org/10.1002/adma.201803351
- Prachi Patel, New Device Marries Solar Cells With Flow Batteries, in IEEE Spectrum – Energywise. 2018. https://spectrum.ieee.org/energywise/green-tech/solar/new-device-marries-solar-cells-with-flow-batteries
PS. Some great names for a band:
“Quantum Rods”
“Photocatalysis”
“Flow Batteries”
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