Life expectancy of a poplar is 40 years. You have heard that poplars do not give you the BTUs that other woods do. That is correct, hybrid poplars will give you about .6 of the energy you can get from hard woods, such as hickory but this shortcoming is offset by the amount of wood these trees generate. I have been using poplars for many years to heat my house. I don't only use that, I also run two kerosene heaters, and the oil burner is set at just below 68 degrees just in case.
History repeats itself.