Sunpower

SUNPOWER - We Do The Math (a three minute read)

The US uses 4 trillion kilowatts/yr. 4,000,000,000,000 KW/year, or 11,000,000,000 KW/day. There are peaks & troughs from day to day, but the maximum load days are in July when we have the most sunshine, so could reap the most power. Yes, I know there are cloudy days, but solar panels still work then (just not as well) & that's generally when the wind is up (which we will discuss another day after I've done more research). 

Sunlight delivers over 5KW/square meter (thermal) on average in the American Southwest. 
11,000,000,000 ÷ 5 = 
  2,200,000,000 square meters of sunshine needed if solar cells were 100% efficient.

And, in 2026, it now outproduces coal power.

Inexpensive screen-printed solar cells are 19% efficient, (yes, there are panels with 34% efficiency & other tricks to boost efficiency even further) but those are brand new, so let's go with the off-the-shelf well-proven systems that cost 20 cents/watt, so we need 
  2,200,000,000 ÷ 19% = 
11,600,000,000 square meters, or (2,589,988 square meters per square mile)
4,479 square miles of standard solar cells.  

Let's increase coverage to compensate for the 60% efficiency of iron-air flow batteries (cheap, no heavy or exotic metals or lithium required) or the newer more efficient sodium-sulfur batteries (also no heavy or exotic metals, lithium-free) as used in German transformer stations to store some (not all) of that power for after sundown & unusual power use. And, if there's a mineral shortage (not likely considering how much sodium is under Lake Erie and how much iron is in Minnesota), gravity batteries are also proven to work at 80% efficiency. Remember, our peak power need is when the sun's up, so we won't need those batteries all the time, so that 60% figure is very conservative & leaves a big margin. And, the batteries don't need to be where the solar cells are.
4,479 square miles ÷ 60% = 
7,465 square miles.

Cover just 7% of the un-urban deserts of just one state of the union, New Mexico (109,000 rural square miles) with solar cells, elevated, so if there's water, you can grow & ranch beneath them. Solar arrays make great habitat for livestock like sheep & pollinators, too, as per this 2021 study, not to mention they're excellent in parking lots, as I saw when I worked at Intel which now has 3 million square feet of solar covered parking spaces.
109,000 X 7% =  7,630 square miles

Long distance DC power transmission loses only about 5% per thousand miles so add just a bit more, say 12%, to send some of that power as far away as Alaska or Maine. *
1.12 X 7,630 = 8,546 square miles.

Problem solved; all the electrical energy needs of the continental US plus Alaska solved using < 8 % of just one state's deserts, just like Heinlein wrote about in 1940. No need for methane-powered gas turbines that leak a greenhouse gas that's 84X as bad as CO2, extremely expensive nuclear plants, drilling for oil**, or the worst power option, coal, which Scientific American found kills a staggering number of Americans. And this helps put the brakes on our undeniable Global Roasting†.

* (Hawaii, blessed with year-round sunshine, like the US island territories & possessions, can be self-sufficient with their own sunpower screens, batteries, & geothermal: No need for trans-Pacific or trans-Caribbean power cables, although we could do it with this plan if we needed to.)

** Our highly skilled oil drillers can transition to geothermal, as shown by this English success story which not only extracts heat and electrical power but lithium for mobile batteries as well.

† Source: https://climate.copernicus.eu/surface-air-temperature-may-2026

#SolarPower #SolarCells #Solar #FlowBatteries 

Short link to here tinyurl.com/sunpowerrr (yes, three r s in a row)