dpinney
commented
9 years ago @drdanley retest with https://www.omf.coop/model/drdanley@verizon.net/drd%20ky%20pvwatts%20test and/or another pvwatts model.
Note that you'll need to re-run the model at least once.
ORIGINAL FEEDBACK https://www.dropbox.com/s/hn3nchmroq4erk4/GOSED%20Notes%2027%20Jan%2015%20drd.docx?dl=0
TODO
PVWatts is a copyrighted name, and it is one word: PVWatts©. Also need to give some credit to NREL along with some sort of hyperlink.Start Date / Run time – should default to Jan 1st and 8760 hours.Start date is not really valid with a year, since we are using TMY data which is a blend of various years and is intended to be representative, rather than an exact year.We need to leave it since the chart library we use requires a year. Also it's handy if the user wants more than 8760 hours.Need a field to specify “tilt”, which should be editable when the user chooses “Fixed”, “one axis” or “azimuth” tracking. Note that there are two different types of one axis trackers – east-west axis (where tilt is meaningless), and north-south axis (where tilt is usually zero in modern grid-tied systems, but could be up to 90 degrees). I don’t know how PVWatts does these calculations, so it may be best to just not offer tilt editing for “one axis” tracking.NOCT, Ref Cell Temperature, Diffuse Fraction, Rating Condition Irradiance: I don’t think that any of these should be user variables.Max Power Temperature Coefficient default to 0.45. It should be stated that this is for modules, and the datasheet value is typically specified as “% per degree C (or degree K)”. Note that this is 0.45%, which is decimal (fraction?) form is 0.0045.I would really like to see an “Inverter AC Size” field so that we can use this program to look at the effects of clipping. Also add line to charts.Added. Defaults to same size as system.This brings up the subject of percent as a number (0-100%) or percent as a fraction. “Derate” is in % while this number and others are in fractions. Need to decide on one or the other and be consistent.Min Required Irradiance for Operation – Inverter datasheets will typically specify a minimum voltage for startup and for MPPT operation. I don’t think this is a value that users could easily get, so I think it should be eliminated as a variable.Tracker rotation limit (degrees), wind stow speed (m/s). I personally think this is too detailed for the purpose of this screening tool, especially the wind stow speed. But if you must use it the first value (rotation limit) needs to be specified as degrees from horizontal (I think – check the code?).Eh, I'll leave it for now. Advanced option. Fixed the rot limit label.FROM SOLARFINANCIAL FEEDBACK
Bounds checking with regexes.Nameplate lines on output.Fix irradiance to global, put it on a separate chart.Charts should start at 0. Except for temperature.FINAL
Update production.