Contains the full lesson along with a supporting toolkit, including teachers’ notes.
Over recent years there has been growing public awareness of the need to rationalise our use of fossil fuels and where possible to replace them with sustainable alternatives. A variety of crops can be used directly or indirectly as sources of fuel.
The Basic Principle
Plants need light; this is their ultimate source of energy. The living cells of a plant require a steady supply of energy but light is not available all the time and some cells never receive light (e.g. in the roots). Besides, very few of the thousands of biochemical reactions in plant cells can be 'powered' directly by light.
In the leaves of plants a process calledphotosynthesis takes place; in effect light energy is used to combine carbon dioxide and water to form glucose. Much of the glucose is distributed to other parts of the plant to power the complex life processes. What is not required immediately may be stored as starch. As plants grow new 'building materials' are required to form more roots, stems, leaves and fruit/seeds. These are composed of carbohydrates (such as cellulose), proteins and lipids (fats or oils). Over 90% of the dry mass of a plant is derived from the carbon dioxide it takes from the air.
If plant material is broken down (e.g., by digestion or combustion) the chemical energy 'stored' in the cellulose, oils etc. is released and may be used for heating or electricity generation.
Through research, (food and agriculture) and knowledge transfer (advisory and education) Teagasc delivers six programmes: