Time for Solar Revolution 2.0
Electricity has been a key to drive growth in almost all the business sectors. Coal due to its widespread availability was/is the primary source of generating electricity across the world. With rapid industrialization, the demand of electricity was increasing continuously which led to over-exploitation of coal. While the electricity demands were being met, the emissions from coal power plants had started posing issues such as global warming, ozone layer depletion, ozone hole, etc. Additionally realizing the fact that coal was a limited resource & electricity demand of world was poised to increase by more than 5 times (Figure 1), scientist in 20th century started seeking other energy sources which were rather non-polluting. It was the result of their continuous efforts that humans could utilize energy of both sun & wind to generate electricity from solar cells & wind turbine respectively. Solar energy, due to its easy and rather free availability throughout the globe was focused upon. And not limited of geographic location, sun rises everywhere.
Figure 1: Region wise electricity demand till 2030 (Source: IEA)
During the mid-20th century, solar cells due to its best power-to-weight ratio were put into use in satellites and space rockets. However due to its high cost and being relatively less efficient (than other energy sources), its use was still limited to space applications. This is when various countries formed research facilities (NREL (USA), NEDO (Japan), Fraunhofer - ISE(Germany)) to promote the growth of solar PV. With evolvement in cell/wafer manufacturing techniques along with development in cell technology, the efficiency curve of solar cell was on rise. In late 20th century various federal government started various incentive programs (like feed-in tariff), upfront subsidy support led to steady development of solar sector.
Now with the technology establishing itself, increased demand for solar panels and futuristic growth of solar market was now visible. It was at this time that various companies around the world decided to venture into solar panels/raw materials manufacturing. While the world was on the move the situation of solar market in India has rather been quiet surprising. In the early 21st century, India only had few distributed solar installations which (almost) without any policy support, were priced at premium rates. It was on 11th January, 2010 that the Government of India, realizing the true potential of solar energy launched the Jawaharlal Nehru National Solar Mission (JNNSM) with a target of 20 GW by 2022. The prices of solar energy around this times were still hovering around INR 12~13/kWh. With the widespread use of solar energy coupled with increasing awareness the prices of solar energy had started coming down. In 2015, India upgraded its target under JNNSM to 100 GW from 20 GW showing our commitment towards renewable energy. This up-gradation was adopted by both central and state government with all of them formulating supportive policies in favour of solar markets.
It was also around 2014~15 that the solar market witnessed a shift. This shift was driven mostly by demand of quality solar modules in the market. On technology front demand for more efficient solar cell had begun which were also free from inherent defects like PID, EL defects, etc. The development and/or implementation of new generation solar cell into solar module i.e. HJT, PERC-PERT, Bifacial cell had begun. While still at laboratory level, it was clear that such implementation had potential to increase the module level efficiency. This efficiency was also boosted by major shift in the manufacturing process (es). Initially the solar modules were manufactured by laying up the cells/strings manually. Additionally there was no provision of capturing/recording in-process electroluminescence (EL) image (EL image shows any type of crack/micro-crack, open solder, etc. in the module). Realizing the need of the hour, entire manufacturing was automatized along with implementation of in-process and post lamination EL image (as shown in Figure 2) which along with increasing the module efficiency also enhanced the overall quality of PV module.
Figure 2: EL images of 72 cell mono & multi crystalline module
Manufacturers now already had reliable & established technologies for manufacturing top notch raw material for PV modules. Along with this various manufactures had already expanded (or were expanding) exponentially (mostly in China due to its favourable manufacturing policies) which led to availability of adequate raw materials around the world. Solar energy by around 2016 had started bearing fruits for the common public in India and around the worldas solar energy prices were below grid parity (as shown in Figure 3).
Figure 3: Development of solar energy prices in India
The solar market now with recent developments is again at tipping point. While the solar energy prices shall not observe any significant change (like previous years), the technology is on verge of serious transformation. In cell/ module level a series of new modules have been introduced like mono/multi PERC, Bifacial and Half-cell based modules with various possibilities within these technologies themselves. Additionally with the introduction of micro-inverters & smart junction box, smart modules are poised to have an increased market share enabling smooth plant monitoring. Now with increasing share of solar energy (& renewable energy) in country's grid, storage shall also have an important role to play. Renewable energy sources which are known to be intermittent in nature, if coupled with correct type and size of storage could power the grid even at non-generation hours. Modules now are also tested extensively under different accelerated conditions to simulate real time operations on field ensuring that they stay put even beyond their declared lifetime. With these developments, we believe that it's time for the sector to move ahead from the notion of evaluating solar system at its buying cost i.e. $/Wp. With solar plants expected to run for more than 25 years, we believe that all the solar installations (be it utility or rooftop) shall be strictly viewed from $/kWh (i.e. the cost of energy generated) over its lifetime. Additionally with the solar energy prices already below grid parity, we believe that the market now should be self-driven without the need of any policy intervention or subsidy (except in few sectors such as agriculture). We believe that instead of focusing on subsidy, the federal and state government should ensure easy disbursement of loans to end consumer (via banks and NBFCs). Such factors shall enable smooth transition of energy sector towards clean & green energy.