More specifically, soft energy technologies have five defining characteristics.
[2] They rely on renewable energy resources, are diverse and designed for maximum effectiveness in particular circumstances, are flexible and relatively simple to understand, are matched to end-use needs in terms of scale, and are matched to end-use needs in terms of quality.
Active residential solar technologies use special devices to collect and convert the sun's rays to useful energy and are located near the users they supply.
Passive residential solar technologies involve the natural transfer (by radiation, convection and conduction) of solar energy without the use of mechanical (active) devices.
The term soft is not meant to be vague, speculative, or ephemeral, but rather sustainable, flexible, resilient, and benign.