Agrivoltaics, saving farms

[Toddsterpatriot]

If that were true you wouldn't still be chasing me around.

Pointing and laughing.

 

[ding]

Pointing and laughing.

still proving my point.

 

[Toddsterpatriot]

still proving my point.

Only if your point was your faulty understanding of physics.

 

[ding]

Only if your point was your faulty understanding of physics.

You sure are worked up.

 

[Toddsterpatriot]

What percentage of solar radiation striking solar panels is in the visible light spectrum.
The answer is 40 to 44%.

What percentage of visible light striking solar panels is converted into electricity?
The answer is 15 to 20%.

So per square meter solar panels effectively reduce the 240 W/m² striking it by:
240 W/m² x 0.44 x 0.2 = 21.12 W/m²

What is the total land surface of the planet?
The answer is 149 million square kilometers or 1.49x10^14 m²

What is the solar radiation striking the total land surface of the planet?
The answer is 240 W/m² x 1.49x10^14 m² = 3.5760x10^16 W

What is the reduction needed to make the planet net cooling?
The answer is 0.7 W/m² x 1.49x10^14 m² = 1.0430x10^14 W

How many square meters of solar panels are needed to change the planet from net warming to net cooling?
The answer is 1.0430x10^14 W / 21.12 W/m² = 4.9384x10^12 m²

What percentage of the total land surface of the planet would need to be covered by solar panels to change the planet from net warming to net cooling?

The answer is 4.9384x10^12 m² / 1.49x10^14 m²= 0.0331 or 3.31% of the total land surface of the planet.

I just bought a new LG refrigerator.

The freezer section is 21 in. X 30 in.

Every time a satellite goes over Chicago it measures my freezer at 40C cooler than my home.

How many of those freezers would it take to change the planet from net warming to net cooling?

 

[ding]

I just bought a new LG refrigerator.

The freezer section is 21 in. X 30 in.

Every time a satellite goes over Chicago it measures my freezer at 40C cooler than my home.

How many of those freezers would it take to change the planet from net warming to net cooling?

I sure did wind you up.

 

[ReinyDays]

ReinyDays

Nothing in these calculations about waste heat or fossil fuels.

What is the reduction needed to make the planet net cooling?
The answer is 0.7 W/m² x 1.49x10^14 m² = 1.0430x10^14 W

How many square meters of solar panels are needed to change the planet from net warming to net cooling?
The answer is 1.0430x10^14 W / 21.12 W/m² = 4.9384x10^12 m²

OMG!

You think solar panels somehow reducing the warming caused by solar radiation.

That's hilarious!

Moving that energy from a solar panel to my coffee maker can cool the planet.

DURR

The answer is 1.0430x10^14 W / 21.12 W/m² = 4.9384x10^12 m²

If you absorb 95% of the solar radiation hitting 4.9384x10^12 m², instead of absorbing 70%,
wouldn't you be warming the planet?

Why do you think there's exhaust gases from solar panels?

CH4 + 2O2 --> CO2 + 2H2O ...

∆E = - 55.7 kJ per gram of methane ... on average only half that energy is converted to electricity ... the other half is wasted on the heat in the exhaust products ... especially keeping water in her vapor state ... so my question is what exactly are solar panels emitting that wastes heat energy ...

Your calculations assume solar panels work at peak efficiency at night? ... where are you getting your numbers from? ... or are you just following ding-a-ling's incorrect logic? ... radiative forcing is generally considered to be 1.8 W/m^2 and Earth's surface area is closer to 5.1 X 10^14 m^2 ... but that's meaningless because solar panel convert SOLAR energy into electricity, not terrestrial longwave radiation ... your vectors are wrong ... and yes, power is a vector value, direction matters ..

Using solar power vectors ... we find that solar panels are net warmers in all circumstances ... and the last sentence in the above quoted post is SPOT-ON CORRECT: "If you absorb 95% of the solar radiation hitting 4.9384x10^12 m², instead of absorbing 70%, wouldn't you be warming the planet?" ... except you forgot to divide by two root two, irradiation follows a half-wave cosine function, so we use the appropriate RMS formula for locations along the equator, otherwise we still have to multiply by the cosine of latitude ...

This is kinda nitpicky in this discussion ... but be careful with the units you're using ... watts are a unit of power, not energy ... they are related but they are two different things ... if we're discussing temperature ... of which "warming" and "cooling" are adjectives thereof ... you want to use units of either joules or degrees Celsius/Fahrenheit ...

Here we can just multiply the wattage values by 1 second to get joules ... but you know there's always someone out there who will throw a temper tantrum over this ... and it's not a petty argument ...

 

[Toddsterpatriot]

Why do you think there's exhaust gases from solar panels?

CH4 + 2O2 --> CO2 + 2H2O ...

∆E = - 55.7 kJ per gram of methane ... on average only half that energy is converted to electricity ... the other half is wasted on the heat in the exhaust products ... especially keeping water in her vapor state ... so my question is what exactly are solar panels emitting that wastes heat energy ...

Your calculations assume solar panels work at peak efficiency at night? ... where are you getting your numbers from? ... or are you just following ding-a-ling's incorrect logic? ... radiative forcing is generally considered to be 1.8 W/m^2 and Earth's surface area is closer to 5.1 X 10^14 m^2 ... but that's meaningless because solar panel convert SOLAR energy into electricity, not terrestrial longwave radiation ... your vectors are wrong ... and yes, power is a vector value, direction matters ..

Using solar power vectors ... we find that solar panels are net warmers in all circumstances ... and the last sentence in the above quoted post is SPOT-ON CORRECT: "If you absorb 95% of the solar radiation hitting 4.9384x10^12 m², instead of absorbing 70%, wouldn't you be warming the planet?" ... except you forgot to divide by two root two, irradiation follows a half-wave cosine function, so we use the appropriate RMS formula for locations along the equator, otherwise we still have to multiply by the cosine of latitude ...

Solar panels reduce the solar radiation striking the planet!!!!!!

LOL!

 

[ReinyDays]

Solar panels reduce the solar radiation striking the planet!!!!!!

LOL!

In what way are solar panels not part of the planet? ...

My calculations are for the panel itself ... the temperature of the solar panel is warmer than the environment in all circumstances ... more panels means more global warming ... not less ... and certainly not cooling ... only a complete moron would think that ... c.f. the Urban Heat Island effect ...

Solar radiation warms the ground ... any radiation not converted to electricity also warms the ground ... not wasted ... the electricity that is generated is used to run a space heater ... to warm the bathroom ... not wasted ...

[giggle] ... I don't think we're running many 100 hp electric motors on panels ... and do they get hot ... now you're wasting heat ...