Negative annual energy

Dear Paul,

I designed a molten salt power tower model, where use the 'optimize heliostat layout', then try to simulate the amount the energy that is produced from the design per year. But I just got a negative value like -3377281KWh. Could you explain that is there any reason that would cause a negative number ? 

Best regards,
Francesca

Hi Francesca,

Can you attach a copy of the .sam file that generates those negative results?

Best regards,
Paul.

Dear Paul,

Here is the file. I'm using SAM 2015.1.30.  Please help me have a look at this model. Thank you.

Best regards,
Francesca

Hi Francesca,

The Power Cycle input parameters "Estimated Gross to Net Conversion Factor" and "Rated Cycle Conversion Efficiency" are both set to 1. Changing those to a more realistic 0.9 and 0.4, respectively, results in positive annual energy.

Best regards,
Paul.