Correct. Many coal-fired plants are constructed at the mine site and the coal is belt conveyed to the plant as it is mined by shovels. The power is transmitted to the grid and its ultimate user. It's much cheaper to transport the power via lines, than it is the coal.
Additionally, coal has about 12.5K btu/lb, where dry wood has about 8K btu/lb. So transportation costs per btu are 1.5 X that of coal. Coal can easily be pulverized into dust which is the most efficient way to burn it. Wood is a bit more difficult to "size" for efficient burning.
It's a different proposition if you are already in the wood processing business - paper, sawmill, plywood, etc. Wood waste - bark, sawdust, trimmings - has to be disposed of anyway, so burning to produce steam has a benefit. The steam heat can be used in the production of electricity, or to dry green lumber. Before pollution laws were strengthened in the 60s and 70s, most sawmills burned their wood waste in "TeePee" burners, rather than trying to generate steam.
Cogeneration of electricity has come back in vogue. Seneca Sawmills in Eugene, OR spent millions($30m) putting in new cogeneration plants that burn their own wood waste. They make steam to power their kilns and produce electricity that they sell back to the grid. This was mandated by Oregon State law. There were also major tax incentives both state and federal to help their return on investment.