At the renewable energy India expo today I had the good fortune to connect with industry professionals and researchers across the energy landscape from battery makers and critical mineral providers to solar energy professionals. During my interaction I gained valuable knowledge about intricacies of manufacturing and how even the seemingly simplest of steps like electrical connection of solar cells, through tin coated copper wires, becomes extremely sensitive given the thin wafers and volume of large scale manufacturing.
It is true that the renewable energy industry has come a long way from its very humble beginnings and it now presents a viable alternative to traditional forms of energy. This in itself is a huge achievement, something that would have been considered impossible several decades ago. But some issues remain that prevent RE from becoming dominant.
On the battery level the answer is obvious. Lithium is a scarce resource. New discoveries will be made but current projections show that there is not enough lithium to be able to satisfy demand for even automobiles let alone home storage solutions. Recycling could help but frankly the complexity of material recycling is being underestimated. New battery materials are urgently needed to address this issue. Sodium ion is a good start but can even more abundant materials be discovered? On the grid scale flow batteries look promising. But what if we could couple electrical energy storage with thermal storage? These questions must be asked by researchers and policy makers.
Solar panels are highly efficient on a weight basis. 1 square meter of silicon solar cells uses only a few 100 grams of silicon. Each being only a few 100 micrometers thick.
But all solar cells need glass encapsulation adding several Kgs of weight. Not just any glass; optical quality glass is necessary. Glass comes from sand but the kind needed to make optical grade for solar cells must be highly pure and that is an unevenly distributed resource ,somewhat scarce.
Glass is important in another renewable energy product —wind turbines. Glass fibers used in wind turbine blades must be made from highly pure sand as well because impurities can reduce the strength of fibers making them more brittle.
Sand purification is an extremely demanding process, usually requiring acid leaching to remove iron oxides that strongly adhere as a coating on silica surface, for optical grade production. Theoretically acid used is recyclable but that takes additional input and given the large quantities of sand used in making glass it is frankly a bit hard to implement.
So it's clear to see that the renewable energy industry faces some fundamental challenges especially on the materials side
If alternative purification techniques could be developed then sand would start looking more attractive as a raw material. On the processing side colloidal silica could provide new ways of making glass films as compared to melt processing methods that could be valuable in the coatings industry and perhaps one day enabling thin films of glass.
Filmmaker Michael Moore had raised the issue of raw materials for renewable energy in his documentary Planet of the humans but it was promptly censored under the pretext of copyright violation. The questions Moore raised though still linger on.
Silicon is inherently dependent upon carbon for production. Glass consumes huge amounts of fossil fuel. Plastics used in solar panels for bonding and in wind turbine blades as resin in GFRP raises questions around the sustainability of these products. Especially considering their limited lifetime.
The renewable energy industry is now mature and has 100s of players in the value chain, most working at assembly level. Yet like most other industries it follows trends and often tends to be conservative. It's hard to expect a manufacturing plant to make swift changes to its production process. The burden lies on researchers to continue to push for materials advantages. Every little improvement ,every small victory matters.
Renewable energy is such an important issue that we need to have hard scientific debates around the materials that make it work. Can we really base the future of the industry on materials that are hard to source?
The decisions that we take today are going to affect the technological landscape over the next 100 years. Let us make sure that we get it right.
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Akshat Jiwan Sharma
Strategy Consultant--Innovation/ Materials science/International relations/Telecommunications/Digital Transformation/Partnerships
Mobile/whatsapp:+919654119771
email:getellobed@gmail.com
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