Solar fraction calculation in Solar water heater

Majdie
Topic Author

12 Dec 2020 11:43 - 14 Dec 2020 11:05 #9105 by Majdie

Solar fraction calculation in Solar water heater was created by Majdie

Greeting All:

In solar water heater module in SAM, I was trying to make the solar fraction close to 1 even though I made the size 10 times with no luck. In below snip, we can see the Aux. with solar is very small and close to zero, yet solar fraction is just 0.76. The reason that I see for solar fraction calculation it divide energy saved by Aux without solar. However, if we consider the solar fraction as energy saved divided by sum of energy saved and aux with solar, then we can be close to one.

Your advice is highly appreciated

Thanks,

Majdie.

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swh-metrics.png

Last edit: 14 Dec 2020 11:05 by pgilman.

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pgilman

14 Dec 2020 12:01 - 14 Dec 2020 12:01 #9111 by pgilman

Replied by pgilman on topic Solar fraction calculation in Solar water heater

Hi Majdie,

SAM calculates the solar water heating model's solar fraction as follows:

Solar Fraction = Q auxiliary only (kWh/year) ÷ System Energy (kWh/year)

Or using the names in the metrics table:

Solar Fraction = Aux without solar (kWh) / Annual Energy Saved (kWh)

The Annual Energy Saved is the sum of hourly or subhourly System power generated:

System power generated (kW) = Q auxiliary only (kw) - Q auxiliary (kW) - P pump (kW)

Best regards,
Paul.

Last edit: 14 Dec 2020 12:01 by pgilman.

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