to elaborate further on the passive and active froms of solar power mentioned;
Passive is like a flower using the air, water, earth, and sun in it's environment to sustain life. You can build a passive solar home in such a way to take advantage of the local environment and it requires no moving part. Things of a passive solar nature would include a solarium(the heating of it via the sun); thermal air heater; an earthship but not is additional comfort systems, so mass and glass, the amount of light(solar heat) let in the structure to increase the temperature of the walls and floor (mass of concrete, sand, and stone) and the angle of the sun in different time of the year limiting the light in the summer (to make it cooler) that enters the structure and increasing the amount that enters in the winter(to make it warmer).
Active would be like a hydroponically grown flower you require a pump to give it water and light bulb to give it light plus the addition of nutrients (yes this could be argued that this is not exactly active but I'm trying). Active solar devices;solar panels (photo volactic panels ) when the panel is exposted to sun it creates electricity; wind turbine creates eletricity via the force of the wind rotating the blades and the blades rotate a generator; heliostat as made in Germany with a sterling engine, the heliostat is an array of mirrors that focus the light energy on a central point that is the hot side of the sterling engine and that engine rotates a generator.
So solar devices use naturaly created energy to create electricity (active) or we can build in such a way to harness passive energy. There is less states of change using passive solar power but our world(western) is built for convience and there for active solar power is needed but also more expensive. Any device that has to change from one type of medium to another loses energy at every change so the passive solar devices are more efficient then active. Sorry about going off on a tangent I hope i've not confused the issue more.
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