Energy is... ? - it's not an easy answer. Energy comes in all different forms, types and sizes.

click image for clarification of types of energy

Energy is a word we use in many ways.  We say we have lots of energy when we feel fit and strong.  We say we are saving energy when we turn lights off.  We say our cars are energy-efficient when they have engines that use less fuel.  There are connections between all these things and with many more, as we will discover when we look around the pages on this website. Energy comes to Planet Earth from the sun and we say that energy is ‘conserved’ when it changes from one form into another.  Solar energy in the form of light and heat fuels the photosynthesis process that enables plants to grow; to take in carbon dioxide and give off oxygen; to provide food for us.  In ages long past it was the decay of plants that formed fossil fuels like coal and oil.  Now we are learning to grow plants to produce ethanol and bio-diesel as fuel for our cars.  It is heat energy that creates the winds that circle the Earth and we use the energy in those winds to drive turbines to create electricity, and to drive windmills that bring water from underground for plants and farm animals.  There are many more stories about this in these pages. Energy can also be wasted when we do not act wisely.  For our own future we must find ways to preserve the energy that Nature gives us.