This report analyzes the economic implications of the Goods and Services Tax (GST) on solar energy storage manufacturers in India. The study examines the impact of a proposed reduction in GST from 28% to 5% on battery production costs, prices, and demand. It explores how this change would affect the demand for batteries, electric vehicles (as complementary goods), and petrol vehicles (as substitute goods). The report also assesses whether the proposed GST reduction would support the government's goal of 100% electric vehicle usage by 2030, considering potential price and demand shifts. The analysis uses economic principles like supply and demand curves to illustrate the effects of tax changes on market dynamics, emphasizing the relationships between complementary and substitute goods and their impact on consumer and producer surplus.