In 1995 ELSAM/MIDTKRAFT equipped the 150MW(e) pulverised coal-fired Studstrup power station, unit 1, for a technology demonstration cofiring of coal and straw. The conversion consisted of establishing a straw pre-processing plant and modifying the burner system. After plant commissioning in January 1996, a 2-year demonstration program was initiated. The objective of the program was to evaluate the influence of cofiring on boiler plant performance, combustion chemistry, heat surface deposits and corrosion, residue quality, emissions, and selective catalytic reduction (SCR) systems. This paper presents the plant conversion and results from the demonstration period. (C) 2000 Elsevier Science Ltd. All rights reserved.