Definitions - v

The proportion of sunlight energy that a photovoltaic cell converts to electrical energy.

The process where worms feed slowly on decomposing materials (e.g. vegetable scraps) in a controlled environment to produce nutrient-rich soil.

A wind generator design where the rotating shaft is perpendicular to the ground, and the cups or blades rotate parallel to the ground.

A wind turbine with the axis or main shaft mounted vertically, or perpendicular to the earth's surface. This type of turbine does not need to be turned to face the wind - the wind always blows across it. Types include Savonius and Darrius.

The evolution of a new species from a group separated from the original species by a geographic barrier.

Rain which fall in the sky but evaporates before it reaches the ground.

Resources extracted from nature in their raw form, such as timber or metal ore.

Virgin paper is paper that contains no recycled content and is made directly from the pulp of trees or, alternatively, cotton.

The proportion of sunlight energy that a photovoltaic cell converts to electrical energy.

The voltage lost along a length of wire or a conductor due to the internal resistance of that conductor. The voltage drop is calculated using Ohms Law.