Solar Photo-voltaic Modules, better known as PV modules have revolutionized the Renewable Energy industry like none other. Despite the worldwide financial meltdown, waning of government aid programs and stiff resistance from the fossil fuel industry monarchs, the world is adding more solar photo-voltaic than ever before. More-over, its not a developed world fad anymore, as developing nations such as India and China are all set to outdo their developed world peers in terms of both total installed solar photo-voltaic capacity as well as yearly capacity addition of solar PV.
To put this into perspective, let’s see this phenomenon in numbers. At the turn of the millennium, the world was adding less than a GW (Gigawatt – 1000 Megawatt) of solar PV annually and the net capacity of solar PV installed worldwide stood at just a couple of GWs. Fast-forward to 2015, the world added more than 50 GW of solar PV in 2015 itself and the total installed solar PV capacity soared to 227 GW worldwide! Geographically too, the world saw some major changes as China took over as the new No. 1 in terms of both “Net solar PV capacity installed” at 43.5 GW and “Annual solar PV capacity added” at 15.2 GW. In contrast, the erstwhile global leader – Germany’s total solar capacity stood at 39 GW while it added only 1.52 GW in 2015. Coming back to the global landscape, no matter which way you look or whosoever leads, the global solar PV growth story is intact, much to the cheer of environmentalists, climate change warriors and clean energy enthusiasts. But amidst all this unprecedented growth, very few have noticed an impending danger – Disposal of Solar Photo-Voltaic waste. All the Gigawatts being added at such a frenetic pace will pose a massive waste management challenge when all these solar PV modules come to the end of their commercially viable life of 25 to 30 years.
Surprisingly, in terms of annual solar capacity addition, Germany not only lost the numero-uno position worldwide to China but also within Europe to UK as the island nation added 3.5 GW in 2015! Meanwhile, India raced past Germany as well on this metric of “annual solar capacity addition” in the global arena as the developing nation added 2 GW in 2015 and jumped to the No. 5 spot, thereby marking some major shifts in the global Solar PV growth story.
Even we, at Longman Suntech Energy, grew at a stupendous 7800% as we introduced the innovative financial solution – rooftop solar PPA – to our customer base in the southern part of India !!!
Thankfully, somebody is thinking. Europe has just put in place the world’s first PV recycling infrastructure in place in the form of PVCycle. The economics of recycling solar photo-voltaic currently supports free pick-up of used PV modules from the installation sites and thus save all the currently installed modules from reaching large land fills. While this may sound as good news, a closer look into the economics reveal something even better – solar PV recycling could not only become a norm all over the world but in the very near future, installers or manufacturers could even earn a few bucks on recycling !!!
How will this play out? A closer look at the dismantling process of a PV module will reveal the key to this question. Upon dismantling a PV module, the two major components that we get a Glass and Aluminum, both of which can be recycled using existing technologies for profit. Plastic, the most significant constituent needs to be recycled at a cost that can be reimbursed by the sale of the end-product and rendering it recycling a revenue neutral process. Last but not the least, its the recycling of Silicon that’s crucial.
Currently available recycling technologies produce silicon cells with efficiency comparable to newly produced silicon cells. What technology we choose depends on how much of silicon we manage to salvage intact upon dismantling of solar PV modules. Intact silicon cells thus salvaged can be processed into new solar cells using standard cell production processes such as texturization, passivation, anti-reflective cost deposition, emitter formation etc. Dismantling processes such as that developed by Frisson research group in early 2000s enable salvage of 80% of silicon cells intact, whereby module components are dismantled using thermal removing. Further improvement to this technique such as that developed by Klugmann-Radzimeska has not only improved the success rate of salvaging silicon cells intact during dismantling process but also increased the efficiency of the process with lower energy consumption and reduced overall process time.
Current outcomes from such processes give us a very encouraging picture. Module level efficiency of PV modules assembled using such recycled silicon cells have been recorded as 15% to 16.4% in case of mono-crystalline solar cells and 12.7% to 15.9% in case of poly-crystalline solar cells. In comparison, these efficiency figures for a PV module assembled using newly produced solar cells stand at 18% to 20% for mono-crystalline and 15% to 17% for ploy-crystalline. Despite this slight loss of efficiency, what is going to tilt the scales in the favor of recycling is lower energy consumption of recycling process as compared to production of silicon cells. Latest recorded energy consumption figures show that it requires only 186 units of energy to assemble a PV module fitted with recycled silicon cells as compared to 400 units of energy required to assemble a PV module fitted with newly produced silicon cells and generating the same amount of electricity as its recycled counter part.