Energy Storage at the Distribution Level – Technologies, Costs and Applications
The proliferation of grid-level battery storage is majorly dependent on the slope of falling price trajectory which depends on the demand of batteries in a country, manufacturing capabilities and efficiencies, hold on supply chains, etc. The energy storage mission by Niti Aayog acknowledges the fact the electric vehicle (EV) adoption in India will be a significant factor to generate the demand for batteries in India, with possible opportunities for India under different scenarios. Further, recently, MNRE issued guidelines for tariff-based competitive bidding process for procurement of round-the-clock (RTC) power from grid-connected RE power projects, complemented with power from coal-based thermal power projects under Section 63 of Electricity Act, 2003. Generators shall supply dispatchable RE power combined with thermal power, in an RTC manner, keeping a minimum of 85% annual availability and also at least 85% availability during peak hours. Peak hours were four hours out of 24 hours and must be specified by the procurer beforehand in the bidding documents. Generators got the leverage to combine energy storage systems for ensuring that it achieves the required minimum annual availability of 85%. However, annually a minimum of 51% of energy shall be supplied from RE sources. This 51% shall also include the output of electricity through the storage system, provided RE sources were used to store energy in the storage system. The bidder will also have the flexibility to choose the type of storage system to be installed like battery energy storage systems, pumped storage systems, mechanical and chemical systems. As an outcome, 400 MW RE projects with RTC supply conducted by SECI resulted in a first-year tariff of INR2.90/kWh. The first-year tariff shall be escalated @3% on an annual basis, up to the 15th year of the 25-year term of the PPA. As a result, the effective tariff for the said project amounts to INR3.59/kWh. However, there has been no declaration on energy storage capacity from winning parties. If, at all, energy storage will be the part of generation assets remains a question considering series of amendments by SECI, starting from 29 January 2020 (refer to table 22). TABLE 22: Series of amendments by SECI
Request for selection: original terms
Request for selection: amended terms
Power generator to plan dispatch of electricity and inform Deleted the concerned state load dispatch center in advance Buying utilities to have the power to issue instructions to Deleted power generator to supply the electricity in a particular quantity and time It is mandated to make available the plant to the buying Deleted utility on an RTC basis The generated energy shall be dispatched through Deleted scheduling of power by the buying utility 90% availability of the contracted supply for every year
80% capacity utilization factor cumulatively in a year; 70% in each month
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