Perovskites could make solar energy self-reliant
The alternative to siliconbased PV cells, which is the speciality of China, has since been developed in the shape of Perovskite solar cells which have also been tried and tested. According to the work done at the National Institute of Advanced Studies, Bengaluru, the efficiency of Perovskite cells, which was about 3 per cent in 2006, has shown a marked improvement and has now been determined to be about 22 per cent, which makes it quite viable.
The Prime Minister recently inaugurated the largest photovoltaic (PV) cell based solar energy plant at Rewa in Madhya Pradesh. While inaugurating this 750 MW plant, Mr Narendra Modi stressed on the need for atmanirbharta (self-reliance). Considering that about 80 per cent of our solar power generation equipment is of Chinese origin, it was the right time and the right occasion to emphasize this aspect as only during the last year we had imported from China solar panels and other related equipment worth US$1.68 Bn.
India is lucky that sunlight is available in abundance, but the challenge lies in the procurement of solar photovoltaic cells and is one of the major constraining factors in our efforts to realise the full potential of solar energy. According to a report submitted by a Parliamentary Standing Committee, in order to achieve the target of 100 GW of solar electricity capacity by 2022, India should have had an installed capacity of 32000 MW by 2017-18. But as of 31 January 2018, the country only had a capacity of 18,455 MW.
As per the standing committee, additional capacity of over 80,000 MW had to be installed in the remaining period which appeared extremely difficult. Paradoxically and simultaneously, and notwithstanding the constraints, the price of solar energy has come down to Rs 2-2.50 per unit from Rs 7-8 per unit in 2014. A serious impediment in this entire exercise of achieving the target continues to be our poor record of indigenous manufacture of solar panels and complete dependence on the Chinese. The Chinese advantage is based on low cost of manufacturing despite the process consuming high amounts of power and being polluting.
In the absence of cheap imports, the current situation may perhaps appear to be disappointing but there are alternatives which need to be fully exploited. Firstly, the solar thermal route for harnessing solar energy has only found limited applications so far. As of now there are only six functional solar thermal plants which meet just a fraction of our total requirement. Understandably, this technology has its advantages but is somewhat more expensive than the PV cell route resulting in reluctance in accepting it. More research in this area could lead to a cut in costs and in increase in profitability.
The alternative to siliconbased PV cells, which is the speciality of China, has since been developed in the shape of Perovskite solar cells which have also been tried and tested. According to the work done at the National Institute of Advanced Studies, Bengaluru, the efficiency of Perovskite cells, which was about 3 per cent in 2006, has shown a marked improvement and has now been determined to be about 22 per cent, which makes it quite viable.
Perovskite is a crystalline form of the chemical Calcium Titanate. It may sound formidable but fortunately all the raw materials for its manufacture are available indigenously, and the process is much simpler, less polluting and less power consuming than production of silicon chips.
Perovskite is the product of Limestone, which is abundantly available in the country and Titanium Oxide obtained from sands containing Ilmenite, an ore of Titanium. Ilmenite is also available in abundance as we have reserves of several million tonnes of this ore in the sands along the shores of Andhra Pradesh, Odisha, Tamil Nadu and Kerala. The present usage of Titanium oxide is confined to the paints and pigments industry as well as in the manufacture of cosmetics and sunscreens being a good protection against UV rays.
The absence of Chinese products from now onwards needs to be considered as an opportunity for accelerated research so as to put this technology to commercial use at the earliest. Perovskite-based solar cells have performed exceedingly well in controlled conditions but the problem of degradation due to weather conditions needs to be addressed. Silicon-based PV cells are almost weather proof; the durability of Perovskite has to be brought up to that level.
The Perovskite technology has the potential of being a game changer in our quest to harness solar energy that is less polluting and offers a low cost solution. The need to allocate sufficient funds for research and for close monitoring in this area need hardly be over-emphasised.
Source : thestatesman
