hardwares that are defined as renewable by sharing one key characteristic – that through generating useable energy in the form of electricity or heat, the resource base is not depleted or significantly diminished. This is a quality not of the hardware itself, but of the energy conversion that is being performed and, in some instances, the way that this conversion through technology is organised. For biomass burning, renewal of the resource is dependent on the replenishment of the stock of wood, energy crops or wastes – a question of organisation and practice rather than of technology. Renewable energy generation hardwares also involve low levels of pollution, including carbon dioxide, but not exclusively so.