OREANDA-NEWS. December 01, 2016. Power plant operators on the 15-state Midcontinent Independent System Operator (MISO) relied more on gas plants in October to meet demand even as overall electricity demand declined.

Natural gas in October accounted for 21.3pc of the MISO generation fuel mix, up from 19.6pc a year earlier, MISO said.

Total electric demand fell by 4.2pc year-over-year to 45.1TWh and was lowest since 2013 for that month amid above-normal temperatures, according to MISO data.

Natural gas captured a greater share of the regions power generation market despite a sharp increase in gas prices as power generators in the region are more reliant on gas plants amid coal plant retirements.

Gas-fired plants dispatched 9.6 TWh in October, up 4pc from the year before. Meanwhile, spot gas prices at Chicago Citygates in October averaged \\$2.89/mmBtu, up by 21pc from a year earlier.

Coal historically has been the key source fuel for power generation in that region. It represented 49.3pc of the fuel mix during October, down from 50.8pc the year earlier.

MISO had 65,152 MWs of installed coal capacity as of 1 January 2016, about 1pc lower than the year before, according to MISO.

In addition, several other coal plants were retired this year in the region which was primarily attributed to low gas prices.

US merchant generator Dynegy closed its 465MW Wood River coal-fired power plant in southern Illinois in June and unit 3 at the Baldwin plant in October. Consumers Energy this year retired 312MW of coal-fired generation in Michigan.

Gas installed capacity in MISO footprint was at 73,190 MWs on 1 January 2016, up 0.3pc from a year before.

Coal units typically provide baseload capacity and account for the largest share of generation across MISO. But gas is capturing more market share in recent years, especially after integrating the gas-dominated south region in December 2013.

MISO, the second-largest US power market behind PJM, breaks fuel-source information for its region into three distinct zones.

MISO's north zone includes Iowa, western Minnesota, Wisconsin, North and South Dakota and eastern Montana. MISO's central zone covers Michigan, eastern Wisconsin, and parts of Illinois, Indiana, Kentucky and Missouri. MISO's southern zone covers parts of Arkansas, Louisiana, Mississippi and southeast Texas.

In MISO's coal-dominated central region, gas-fired generation in October represented 12.8pc of the fuel mix, down from 14.5pc a year earlier. Coal was used to generate 64.7pc of the central zone's power in October, down from 70.4pc a year earlier. Nuclear generation rose to 17.7pc from 10pc.

In the south region gas accounted for 63.4pc of electric output in October, up from 54.8pc a year ago. Meanwhile, coal rose to 20.8pc from 17.2pc. Nuclear generation saw a sharp decline in that region, falling about 11 percentage point to 12.5pc.

The northern region, another coal-dominated zone, used coal for 48.1pc of the electric supply in October, up from from 47.2pc the year earlier. Gas-fired generation supplied 5.4pc of the electric demand, down marginally year-over year.