Democratic Underground - To those who say Solar cannot provide enough of our energy needs

I've read it here on DU in the past that solar power and wind power is all well and good, but it can *never* totally replace fossil fuels. The thinking usually goes like this: cars need some kind of fuel and so do factories and to heat buildings. That sounded like a challenge to me so: 1) Electric Vehicles, and 2) concentrate sunlight to make heat for factory processes and to warm our living spaces.

melt rocks with sunlight

How about a 6' parabolic mirror that melts steel and even melts rock with only the power of the sun. The temperature at the focal point: 3500 degrees C; no known material can withstand that heat.

http://www.youtube.com/watch?v=z0_nuvPKIi8

If it gets so hot that it can melt any known material, why not put concentrated solar to work taking the place of fossil fuels in some industrial uses:

making cement

Cement is made by heating limestone (calcium carbonate), with small quantities of other materials (such as clay) to 1450 °C in a kiln, in a process known as calcination, whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form calcium oxide, or quicklime, which is then blended with the other materials that have been included in the mix . The resulting hard substance, called 'clinker', is then ground with a small amount of gypsum into a powder to make 'Ordinary Portland Cement', the most commonly used type of cement (often referred to as OPC).
Portland cement is a basic ingredient of concrete, mortar and most non-speciality grout.

http://en.wikipedia.org/wiki/Cement#Portland_cement

drying

http://www.process-heating.com/Articles/Drying_Files/8b00827d50368010VgnVCM100000f932a8c0____

Example: Coffee
A relatively new method of drying coffee is solar drying. Solar coffeee dryers are more economically sound than mechanical coffee dryers because they don't rely on fossil fuels or electricity. They are also more efficient than the patio drying technique because their hotter drying temperatures dry coffee beans at a faster rate. While solar coffee dryers have great potential for saving energy, they are not widely used today. For more information about solar coffee drying systems, visit EcoVentures International or the MesoAmerican Development Institute.

http://www.coffeeresearch.org/agriculture/drying.htm

make biofuels

A U.S. startup has developed a process that uses concentrated solar heat to vaporize biomass into synthetic fuels, a system the company says is cleaner and more efficient and can produce twice as much fuel per ton of biomass as existing systems. In the process, a network of solar mirrors direct sunlight at a mounted gasifying unit, heating ceramic tubes to 1,200 to 1,300 degrees C. Any biomass, such as wood and crop waste, that is passed through the tubes becomes vaporized and is converted into synthetic gas, the company says. At such extreme temperatures, the process leaves behind little tar residue, which the developers say can be expensive to get rid of and can kill the catalysts that reform the product into liquid fuel later in the process. And unlike other gasification processes — in which the heating comes from the burning of 30 to 35 percent of the biomass — this system requires no biomass to heat the unit, said Alan Weimer, a chemical engineering professor at the University of Colorado, Boulder, who is working with Colorado-based Sundrop Fuels to commercialize the process.

http://e360.yale.edu/content/digest.msp?id=2315

Maybe a 6' mirror is too small. So, just make a bigger parabolic mirror. How much would it cost to make a 40' parabolic mirror? One of the links I reviewed stated an annual gas bill of $1 million for a processing plant that used gas heat to dry the product. How many mirrors can you buy for $1 million? Need more heat? Imagine a line of 40' solar concentrators from one end of the building to the other.

The parabola shape can be adjusted to tailor the focal point to be as far or as near the mirror as desired and a molten salt can be heated by this process, the heated salt can then be pumped through the machinery to provide the industrial processes that heretofore would require burning natural gas.

What part of *free energy* don't these geniuses understand?

To those who say Solar cannot provide enough of our energy needs [View All]