The DSCR model does not limit the debt fraction of total installed cost. For systems with a lot of revenue, the model results in a debt fraction > 100% and negative equity, which causes an IRR = NaN.

Fix by adding an input to set an upper limit on allowable debt fraction when using the DSCR model?

To replicate, open the CSP generic model, single owner model. On the revenue page, switch to 'Specify PPA Price' and change the PPA price to 0.18.