U.S. Energy Information Administration logo
Skip to sub-navigation
This page has no sub-navigation. Skip to page content.

Today in Energy More Today in Energy

Posted May 20, 2026

Coal remains competitive for power generation in the central United States ›

Daily MISO Michigan Hub spark spread and dark spread (Jan 2023-Apr 2025)

Data source: U.S. Energy Information Administration, based on data from S&P Global Market Intelligence
Note: The specifics of the calculation methodology are detailed in our 2017 Today in Energy article, with minor adjustments to heat rates and heat contents used. The heat rate used for the dark spread was 10,579 British thermal units per kilowatthour (Btu/kWh) while the heat rate for the spark spread was 8,365 Btu/kWh.

In the first four months of 2026, electricity, natural gas, and coal prices suggested continued favorable economics for coal generation in MISO. The dark spread of coal, the difference between the fuel costs for coal-fired generation and the wholesale electricity price, in the Midcontinent Independent System Operator (MISO) region outpaced a similar measure of revenue relative to fuel costs for natural gas-fired generators known as the spark spread.

More ›

Previously in Today in Energy

Energy Education