0.5%-2% gross power generation of coal power plant is consumed by vertical spindle pulverizer (VSP), and it is essential to select a VSP with better operational performance. Simulated studies of lab-scale mills, which show the similar breakage mechanism with VSP, and industrial sampling on VSPs are conducted to compare energy efficiencies of E and MPS type VSPs (with the grinding media of balls and tread rollers, respectively). The classical energy-size reduction model is modified with the addition of particle size in the exponential form to compare the grinding energy efficiency (product fineness for the certain specific energy) of two lab-scale mills. Also, differences in structure and operational parameters of lab-scale mills" are considered. For the industrial sampling tests of two VSPs, recorded data and size distribution of sampled materials are preliminarily compared. Product t(10) is selected as the bridge to connect the specific grinding energy and size distribution of products. The modified breakage model is combined with the King's equation to compare the energy efficiency on the premise of feed in the same fineness. Comprehensive comparison of the results obtained from both lab-scale and industrial-scale VSPs suggests that the MPS type VSP shows the higher grinding energy efficiency and lower total energy consumption. (C) 2017 Elsevier Ltd. All rights reserved.