OREANDA-NEWS. July 13, 2017. Gas-fired generation in the Midcontinent Independent System Operator (MISO) was 26pc lower in May than the year earlier because of lower electricity demand, higher renewables output and as power generators continue to rely more on coal-fired generation this year on rising gas prices.

Gas accounted for 21.2pc of MISO generation fuel mix in May, down from 26.7pc a year earlier, the grid operator said in a monthly report. Total electric demand in May was down by 4pc from a year earlier to about 45.5TWh because of cooler weather.

The data implies gas-fired units in May dispatched 9TWh, down by 26pc from May 2016. Generation from coal-fired power plants in May increased by 10pc from a year earlier to 20.7TWh.

Gas-fired generation has declined from the year-earlier levels in each of the previous four months amid year-over-year increase in gas prices. The average spot gas price at the Chicago Citygates in May was $3.01/mmBtu, 56pc higher than the year earlier. Gas delivered to Mich Con Citygates averaged $3.08/mmBtu in May, rising 57pc.

Average coal prices in May across the MISO footprint rose 6pc from a year earlier, according to MISO.

"The increase in fuel prices was a major factor in the increase in energy prices" in May compared to last year, MISO said.

Day-ahead and real-time locational marginal prices in May averaged at $30.25/MWh and $29.70/MWh, respectively. In May 2016 those prices averaged $22.85/MWh and $21.81/MWh, respectively.