> how many watts per square meter are available in sunlight times the
cosine of the angle of incidence times PV area times various efficiencies
approaching zero watts.

Alas, you don't even need the fancy math.  Just "watts per square meter in
sunlight" would be enough.
This fallacy isn't unique to non-english speakers, or poorly written
marketing speak.  People just misinterpret phrases like "the sun is a
limitless source of free energy."  Check out the "solar" projects on
kickstarter or indiegogo...

_____

The device shown would approach its claims if PV was double the width.
Meets or exceeds them at 3 x the width.
So a 2x wide device with PV edge to edge is OK.

Note that there are about 4 hours of full sun equivalent on average in most
places overall annually.
Above 6 rarely in mid summer in some places. (7.4 in Kabul)
About 1.x /day in NYNY.
Well under 1 hour/day in midwinter in Amsterdam.
______

PV power out:

1,000 Watts/m^2 x Area x Encapsulation loss x packing density x cell
efficiency

"Losses" are actually 1-loss fraction)

Insolation in peak sun is 1 Watt per 10 cm^2

EL about 0.9 if trying well. (0.98+ with super high$ effort)
Add external glass =3D about 0.8 (or lower)
PD =3D 0.9 good 0.8 fair effort , lower if spread out, > 0.9 is hard
Z =3D 17.5% is typically good mono Si.
23% is best available.

MUST have direct sun on panel to get anywhere near max output.
Even on brightest day with indirect light - 20%would be exceptional, 10% if
good bright sky and local reflective surfaces, 5-10% if trees etc but panel
angles skwardish.

Indoor artificial BRIGHT lighting << 1%.



           Russell McMahon
           Applied Technology ltd
           Auckland, New Zealand.
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