Here are the specs on Schott solar panels:

Rated Power at STC (Standard Test Conditions)
This will be the "advertised" wattage of the panel you're looking at (e.g. 180 watt or 205 watt).
Rated Power Tolerance (%)
ASE 250 - +/-2%
ASE 260 - +/-2%
ASE 270 - +/-2%
ASE 280 - +/-4%
ASE 290 - +/-4%
ASE 300 - +/-4%
ASE 310 - +/-4%
Rated Power Per Sq. Ft. (Watts)
ASE 250 - 9.6
ASE 260 - 10.0
ASE 270 - 10.3
ASE 280 - 10.7
ASE 290 - 11.1
ASE 300 - 11.5
ASE 310 - 11.9
Module Efficiency (%)
ASE 250 - 10.3
ASE 260 - 10.7
ASE 270 - 11.1
ASE 280 - 11.5
ASE 290 - 11.9
ASE 300 - 12.4
ASE 310 - 12.8
Materials Warranty (Years)
1
Power Warranty (Years)
20
Cell Type
Ribbon
Maximum Power Temperature Coefficient (% per °C)
-0.47