Researchers studied energy usage in growing willow for biomass in Poland. They compared two methods: traditional coppicing and a newer method called Eko-Salix. They wanted to see which method was more efficient. The research found that the energy gained from the willow was much higher than the energy needed to grow and harvest it. In fact, the energy gain was between several to over twenty times higher than the energy input. So, both methods are great for setting up these willow plantations.