Chennai: Nearly 660MW of solar power projects in Tamil Nadu are likely to be commissioned before March 31 this year, supplementing existing capacity but at a steep `7.01 per unit for 25 years.TN enjoys early mover ad vantage in the renewable energy sector, especially with wind plants, but solar has been slow to take off. Though MoUs have been signed for 1400MW, many big and small solar power projects like the one launched by the Adani group were hit by heavy rains, thereby delaying work. Only 70MW is ready in the Adani project out of the total projected 648MW.echnically , projects which are commissioned after March 31 should not get `7.01 per unit, but Tamil Nadu Electricity Regulatory Commission (TNERC) is said to be working on a viable plan for those which have already signed MoUs with Tangedco and were hit by adverse weather conditions. Opposition parties are opposing extension of the tariff beyond March 31 as across all states, solar power tariff has been consistently failing and is now below Rs 5 per unit..Two solar power companies which signed memorandum of understandings with the state government during the global investors meet in September last year have commissioned 280MW. “Su nEdison has commissioned 150MW of solar power projects and Welspun has commissioned 130MW. Beyond these two, all others are smaller companies,” said a senior Tangedco official.