Yes, you're right. Maryland actually has more people than Denmark. Maryland gets a lot of power from nuclear, though (Calvert Cliffs).

This Danish goal, getting rid of coal plants by 2025, may not be hard to achieve, as they can import electricity, using sub-sea HVDC, from Norway, which has plenty of hydro, or by importing it from Sweden, which has plenty of nuclear and hydro. Running all of the country on wind power is a mirage. Where does the power come from when the wind doesn't blow, which may happen from time to time ?