The journey from Rs.17.91/kWh to Rs. 2.97/kWh

It all started at Rs. 17.91/kWh. This was the tariff of solar PV set by the Central Electricity Regulatory Commission(CERC) for the year 2010-11, and the PPA tariff for the 78 projects(98 MW) selected under the Rooftop and other Small Solar Power Plants(RPSSGP) scheme. This was one of the very rare schemes where there was no reverse bidding. Soon after, the JNNSM reverse bidding started, and prices started tumbling. In the first reverse bidding for 150 MW of projects under the Batch 1 of Phase 1 of the JNNSM in December 2010, the lowest bid was Rs.10.95/kWh and the average bid was Rs. 12.16/kWh. In the subsequent bidding(Batch 2 of Phase 1) in December 2011, the lowest bid dropped to Rs. 7.49/kWh, which many thought would make the project unviable(the project got commissioned on time). The lowest bids kept dropping till it touched a new low of Rs. 2.97/kWh(first year) or Rs. 3.29/kWh(levelised) in Rewa last week(more here).
What has been the journey like? According to the MNRE, there have been 44 reverse bid auctions in India since 2010 under various schemes(JNNSM and states, excluding Rewa), and under various mechanisms(bunding, VGF, tariffs with escalation/without escalation, etc). The numbers are quite fascinating and the price drop has been influenced various factors, but the cost of the installation has been the most important factor. Scale of the projects and cost of capital have also helped.
The downward journey of the tariff can be accessed here. The table will be regularly updated.