I’ve always heard there was about 1000 watts/square meter of potential solar power at noon on the equater and between 600-800 in the U.S.
This link tends to agree.
http://hypertextbook.com/facts/1998/ManicaPiputbundit.shtml
600 W/M2 is 60W ft2, then average that for a 24 hour cycle, and also from North to South in the CONUS, over all the seasons and account for “average” daytime cloud cover.
The nunber I used, 7 W/ft2, is from an engineering textbook.
Solar proponents like to use Phoenix AZ at noon in July for a benchmark but in Troy NY at 10AM in November the number is a bit different.
Perhaps at noon but you need the average value combined with energy storage to compare to power sources.
Unless you we only going to use the power at noon at the equator.
The World Meteorological Organization defines “sunshine” as direct irradiance from the sun measured on the ground of at about 120 watts per square meter. In the case of scattered clouds (cumulus, stratocumulus), the steepness of the transition is high and the irradiance measured from the cloudy sky with a pyrheliometer is generally lower than 80 Watts per square meter.
That means that under the best of circumstances (no clouds and using the entire light spectrum with no loss - an impossibility) a square-meter collector will only power two 60-watt bulbs during noon time.
You can’t make a dollar out of fifteen cents (without government assistance).