this a 220 watt bstc* 5~30% gain solar panel, that is right 220 watt bstc*5~30+ gain panel, built in America by Americans , these panels are built with full bifacial G1 158.75x158.75mm  mono perc cells they are not that cut cell crap, with clear back sheet these panels can produce 5%- 30%  increased output in optimized conditions, they are tested full power and have full warranty, these 12 volt solar panels are ready for all your needs, they can be used for commercial or residential settings, they are 58.7 inch x 26.625 inch 24 pounds, perfect for that small place, they can be connected in series for 24 volt and 48 volt systems, these are not flimsy panels no they are hardy with 3.2mm tempered glass fronts, the 5 buss bar mono crystalline cells make these panels perfect for low light areas, 40mm  heavy duty frames that can be used in a bolt down or clamp system, this panel has the same diodes as all manufactures,  this panel has A transferable 25 yr. limited output warranty, a copy will be sent with every panel, we are proud to be assembling  panels in America, this panel is made with American and imported materials as all American solar panels are, we have been in business for 20 years and are happy to bring these new products to market, we did a flash test of just the back of this panel and it was 127 watt wow, we will supply a copy of the front and back test sheet with each panel, where is your panels test sheet

we made 100 of these before we could get them to market one buyer bought them all this panel is limited  

 Electrical Data
Maximum Power Output:
 220 Watts ~282.0 watts
Max Operating Voltage (Vmpp):
 20.98Volts 
Max Operating Current (Imp):
10.58Amps - 13.75 amps
Open Circuit Voltage (Voc):              
25.20Volts

Short Circuit Current (Isc):
10.98 Amps - 13.75 amps
Module Efficiency:
 19.2% -24.96%

Temperature coefficient of Voc: -0.31% °C
Temperature coefficient of power: -0.29% °C
Temperature coefficient of Isc current: ±0.05% °C
NOCT (nominal operating cell temperature): 45 ° C (± ° C

*The efficiency of BSCs is usually determined by means of independent efficiency measurements of the front and rear sides under one sun. Sometimes also, the BSC is characterized using its equivalent efficiency defined as the efficiency of a monofacial cell able to render the same power per unit area as the bifacial cell at the same test conditions. Alternatively, the equivalent efficiency has been defined as the sum of the front and rear side efficiencies weighted by the relative amounts of irradiance on both sides.

Another related parameter is the Bifaciality Factor, defined as the ratio of the front and rear efficiencies when illuminated and measured independently.

${\displaystyle {\text{Bifaciality factor }}(\%)=\left[{\frac {\eta _{\text{front}}}{\eta _{\text{rear}}}}\right]\times 100}$

Also specific to BSCs is the Separation Rate , that intends to measure the Bifacial Illumination Effect predicted by McIntosh et al. in 1997 by which, the electrical output of BSCs operating under bifacial illumination would not necessarily equal the sum of the front-only and rear-only electrical output, i.e. it is not merely a linear combination of the monofacial characteristics:

${\displaystyle {\text{Separation rate }}(\%)=\left[{\frac {X_{\text{front+rear}}}{X_{\text{front}}+X_{\text{rear}}}}\right]\times 100}$

Typically X represents one of the cell characteristic parameters such as the short circuit current J_sc, the peak power P_max or the efficiency η. Furthermore, to characterize BSC operation under simultaneous front and rear irradiation, the irradiance gain, g, defined as:

${\displaystyle g={\frac {G_{f}+G_{r}}{G_{f}}}}$ so that ${\displaystyle x={\frac {G_{r}}{G_{f}}}=g-1}$

and a bifacial 1.x Efficiency can be defined as the efficiency obtained under a simultaneous irradiance of a certain amount on the front face and x times this amount on the rear side of the BSC. Then the actual gain of a BSC with respect to a monofacial one can be expressed through the Gain-Efficiency Product, which is the product of the irradiance gain g and the bifacial 1.x Efficiency.

references