General biomass information

Direct seeding experiment on weeded , fenced site . A woodland mix of ash , oak , cherry , hazel , hawthorn , field maple , dogwood ,  blackthorn , spindle , guilder rose , wayfaring tree plus areas of sycamore and sweet chestnut . Third growing season after direct sowing at a rate of 100,000 viable seed per hectare . Rapid early growth and mixtures of tree heights and spacing . Location: Watton Farm , Hampshire , England .This section contains general background information about biomass and woodfuel.

When we talk about biomass for energy, what exactly are we talking about?

What is the point of using biomass for energy, rather than other fuels and energy sources?  And how can we be sure we do it in a way that is sustainable and actually gives saving in greenhouse gases compared to the alternatives?