How does a solar water-heating system work?

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Active vs. passive solar water-heating systems for solar energy

Every solar water-heating system features a solar collector that faces the sun to absorb the sun’s heat energy. This collector can either heat water directly or heat a “working fluid” that’s then used to heat the water. In active solar water-heating systems, a pumping mechanism moves heated water through the building. In passive solar water-heating systems, the water moves by natural convection. In almost all cases, solar water-heating systems work in tandem with conventional gas or electric water-heating systems; the conventional systems operate as needed to ensure a reliable supply of heated water.

Other types of systems for capturing solar energy:

  • Photovoltaic systems, commonly called PV systems
  • Concentrating solar power systems, commonly called CSP systems
  • Transpired solar collectors, commonly called solar walls