Howard Electric's power is supplied by Central Electric Cooperative and Associated Electric Cooperative Inc. (AECI) in Springfield, Missouri. AECI is owned by and provides wholesale power to six regional and 51 local electric cooperative systems in Missouri, northeast Oklahoma and southeast Iowa. Its system serves more than 910,000 members.

AECI has a diversified mix of generation resources to supply reliable, economical electricity to member systems. AECI's resources include baseload generation supplied by two coal-based plants producing low-cost, around-the-clock power; intermediate generation provided by three efficient, low-emissions combined-cycle natural gas plants; and four peaking plants that provide power when demand rises to peak levels on cold winter or hot summer days. AECI also has contracted power sources, including renewable hydropower and wind energy from northwest Missouri's first utility-scale wind farms. AECI implemented its "Take Control & Save" energy efficiency program systemwide in 2008 to build upon the longtime energy efficiency efforts of member cooperatives.