Solar savings fraction

In discussing solar energy , the solar savings fraction or solar fraction (f) is the amount of energy provided by the solar technology divided by the total energy required.

The solar savings fraction is thus for solar energy use, to 1.0 for all energy provided by solar. The solar savings is one of the most important factors in the world, the operation and the climate. As an example, the same solar-thermal water heating system installed in a single-family house in Arizona might have f = 0.75 (75%), while in a much colder and cloudier climate, like Pittsburgh, PA, might only have a solar fraction of f = 0.3 (30%) or so. Great care is thus needed in designing such systems, and in evaluating their economics.

To increase the solar savings fraction, the energy conservation measures should be used in the solar energy collection system. Doing so reduces the need for hot water or space heating, for example, and typically provides the best economic return on the total investment, including the solar energy system.

See also

  • Active solar
  • Passive solar
    • Passive solar building design
  • Solar power
  • Renewable energy
  • Autonomous building
  • Architectural engineering


  • Walter T. Grondzik; Alison G. Kwok (6 October 2014). Mechanical and Electrical Equipment for Buildings . John Wiley & Sons . p. 301. ISBN  978-1-118-61590-4 .

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