Bioenergy: Fibre Fuel
Most green plants have large amounts of a stiff material called cellulose. Cellulose is one of the main ingredients in wood, and is extracted for use in papermaking. And green plants manufacture cellulose from sugars, which they make during photosynthesis.
Because the cellulose is made from sugar, it contains a lot of stored chemical energy, energy that originally came from the sun. This chemical energy can be released as heat when wood is burned.
As we know, wood has been used as a fuel far longer than any fossil fuel. In fact in some countries, wood is still the main fuel for heating and cooking. In places where wood is scarce, other forms of plant fibre are burned. Grass, peat, and even cow manure can be used as a fuel, but these materials make very smoky fires!
As long as these materials are allowed to grow back as soon as they are used, they are considered a source of renewable energy (green energy). But, if too much wood is harvested too rapidly, or in a way that damages the soil or other parts of the ecosystem, some severe environmental problems can result.
Fibre Fuel
