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- Solar Turbines: Tree Huggers: How Many Wind Turbines Would It Take To Provide Electricity To The Dallas Fort Worth Area? (4/9/2012)
- Solar Producer: When Will America Use Nuclear Energy To Produce Needed Electricity? (7/14/2011)
- Solar Power: How Many Sq Ft Of Solar Cells Will Provide 50% Of The Average Fl Home’s Power Needs? Cost For Entire System? (4/27/2012)
- Solar Turbines: What Would Be The Cost Of The Solar Cells Needed For A 750MW Plant In A Region Where The Intensity Of The Sunl? (8/24/2011)
{ 4 comments… read them below or add one }
Electricity consumption in the world is about 1013 kWh / year. If we assume a system efficiency of 10% and the solar cells are placed so that solar radiation is 1500 kWh/m2 year on average so we would need approximately 70 000 km2 of solar cells to provide the world with electricity. It represents less than 5% of Sahara’s surface or just 12 m2/person. In a global perspective coincides also variations of solar radiation well with variations in electricity consumption. In hot climates are used as much electricity to operate cooling equipment
Just cover the moons surface with them and connect up with a really long cable.
It is just a mental excercise, it cannot be done on this planet
To be honest, it depends on where they are placed. If power lines are run from the North and South Hemispheres, the change in light as the seasons pass can be counteracted with power from the opposite Hemisphere of where it is needed. Considering the massive amounts of transmission this would take, it would be much cheaper to do my “dams” idea:
http://ca.answers.yahoo.com/question/index;_ylt=Al5IAmTyVKeM2JB4BSE_BF7AFQx.;_ylv=3?qid=20111028193518AAq0JGx
…or substitute power with some wind, tidal, hydro, geothermal atmospheric pressure and biomass energy.
I can’t tell you the amount off hand, but I can tell you that the number of solar panels required depends on where the panels are placed. The ones offered for homes here are 90% efficient – so if it were possible to capture all of the light that hit the Earth (though that would be worse than our current problem) – we’d only get 90% of the energy that comes to the Earth from the Sun converted into electricity (Way more than we use…). As to placement, there’s the tilt of the Earth, clouds, heat/cool, etc. (Solar panels operate more efficiently when colder, and more effectively when more light is hitting them.).
To conclude, you could estimate the number but it would never be exact until it was actually done.
This of course assumes that they are not placed in space.
According to the IEA (International Energy Agency) 20181TWh of electricity was produced globally in 2008.
So in theory we could divide the 20181TWh produced by the hours in the year (8765), that gives us 2.3TW as the Hourly electricity requirement.
We could quickly search for a 1 m^2 photovoltaic sell like BP 3125 and find it’s rating to be 125W (at 12V).
Dividing our electricity requirement 2.3TW / 125W (because the sun does shine on the earth 24 hours a day) gives us a requirement of 18.4 x10^9 m^2.
That is 18,400 km^2 of solar panels required (an area half way between the sizes of New Jersey and Connecticut) to be spread around the world and linked together on a global network to generate 2008 electricity generation levels (negating power loss in conversion and transmission).