What worked in favour of the developers was the fall in module prices, which are down ~17% for from $0.30 per watt at the time of their bidding to around $0.25 per watt at present, that translates into a benefit of nearly Rs.3.4 million per MW. But Crisil feels the arithmetic did not countenance a sharp depreciation in the rupee to more than Rs.73 per dollar, which has wiped off the gains from lower module prices. That, in turn, will compress the debt servicing cushion available for these projects. What is complicating the picture is the levy of safeguard duty on imported solar modules of 15-25% for two years, with effect from July 30, 2018. A weak rupee and safeguard duty would spike up project costs by ~20%. In such a situation, viable tariff for future projects will have to be higher by 30 paise per unit,” feels Manish Gupta, director, Crisil Ratings.