Spot prices of power have risen recently on the back of higher demand from the states and power producers, constrained by fuel paucity, selling less at the Indian Energy Exchange (IEX). The average power price on May 11 at IEX was Rs 5.5 a unit, 57% higher than the same day last year. According to sources, states such as Gujarat, Bihar, Maharashtra and West Bengal have significantly increased their purchases from the exchange amid declining \u2018sell bids\u2019 by private power plants. For a 15-minute trading block, spot prices surged to as high as Rs 8.1 per unit on May 11 \u2014 about 53% more than the highest rate in May last year. The volume of power traded in the first half of May, 2018 at IEX is 2,244 million units (MU), 13% higher than the same period last fiscal. The average power price at IEX in the the same period has been Rs 4.1 a unit, about 37% higher year-on-year. As per the latest data available, electricity procured by Bihar (324 MU) and Gujarat (1,275 MU) from power exchanges in March 2018 were annually 263% and 80% higher. Similarly, with 365 MU and 429 MU, West Bengal and Maharashtra had increased their March spot market power purchases by 16% and 9%, respectively. Sources in Bihar\u2019s energy department told FE that the state has ramped up spot power procurement as has been receiving about 35% lesser power from their actual allocation of 3,500 MW from the units of NTPC and NHPC. At the same time, Bihar\u2019s peak demand in May has already touched 4,700 MW, 15% higher than last year. A 500 MW unit in NTPC\u2019s Farakka power plant is undergoing planned maintenance, which sources said, might have affected supply to Bihar and West Bengal. Gujarat has raised its procurement from IEX after the imported coal-based power plants of Adani and Essar Power stopped about 2,500 MW supply to the state after these plants were denied to raise tariff to compensate for higher prices of imported coal by the Supreme Court in April last year. Simultaneously, the peak power demand in the state has also increased to 16,000 MW. The power prices in the exchange are also rising due to the disparity between the buy and sell bids. Power generators are not able to offer enough electricity on account of coal supply shortage. Among the power plants with exposure to the merchant market, as on May 13, CESC\u2019s Dhariwal plant had coal stock for five days, JP Power\u2019s Bina plant had stck for four days, while Adani\u2019s Tirora plant had coal to last for three days only.