Defaults come from NLR TMY weather (coldest hour, hottest modeled cell). Code calculations (NEC 690.7) use the ASHRAE extreme annual minimum, which is usually colder — enter it above. β is the CEC-measured coefficient; NEC 690.7 calculations use the datasheet value.
Microinverter tables are not shown for panels under 200 W.
SolarEdge and other optimizer-based systems size strings by the optimizer rules — use the manufacturer’s designer. Reference inverters: most named in SoCal permits since Oct 2024.
Expected production in Southern California
NLR PVWatts v8 · Cali-Graf calculation
City
kWh / kW / yr
kWh / panel / yr
kWh / system / yr
Sun, kWh/m²/day
Los Angeles
1,676
302
9,050
6.08
Palmdale
1,835
330
9,909
6.69
Chula Vista
1,696
305
9,158
6.11
Huntington Beach
1,643
296
8,872
5.89
Riverside
1,696
305
9,158
6.21
Santa Clarita
1,724
310
9,310
6.28
Estimate for comparison, not a quote: shading, roof orientation and local losses change real output. Roof mount, 20° tilt, south, 14% system losses.
Questions & answers
How efficient is the Merlin Solar Technologies RFP-F036W180S?
Calculated from the panel area (1.09 m²): about 16.5% for the 180 W class. 180 W over 1.09 m² equals about 165 W per square meter.
How much energy does one panel produce in Los Angeles or Palmdale?
PVWatts v8 with typical-year weather gives about 302 kWh per year per 180 W panel in Los Angeles and about 330 kWh in Palmdale (20° roof, facing south, 14% system losses).
How much power does it lose on a hot roof?
With γ = −0.317 %/°C, at a 77 °C cell temperature (hottest modeled hour in Palmdale) output is about 16.4% below the STC rating.
Sources
California Energy Commission — Solar Equipment Lists, PV Module List (snapshot Oct 7, 2026).
RETC — PV Module Index report.
NLR (formerly NREL) — PVWatts v8, NSRDB PSM v3 typical-year weather for Los Angeles, Palmdale, Chula Vista, Huntington Beach, Riverside, Santa Clarita.
Cali-Graf calculations — formulas and inputs are shown next to each calculated value (efficiency from area, temperature-corrected voltages, string sizing, energy estimates).
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