Thanks to the advances of solar power technology, we can now power manufacturing processes by taking advantage of all the free energy from the sun. The price is right, and we can lower our carbon footprint and use green energy as well.
Here is how the energy from the sun can be maximized:
Location, Location, Location
In order to take advantage of the sun’s energy, it is best to set up technology were there is a lot of sun, and few cloudy days.
Also, where the land is shadowless and there is a lot of space, like the Mojave Desert in California.
Heliostats Direct the Sunlight
The company Heliogen has heliostats set up in the Mojave Desert. Heliostats differ from solar panels because they don’t absorb sunlight, but redirect it to stationary receivers for absorption.
Each one of these heliostats is 16 square feet and has mirrors that reflect a kilowatt of sunlight to the top of a five-story tower. On the top of the tower is a silicon carbide receiver that absorbs this sunlight.
The Sunlight is Hot Enough to be Converted into Power
The temperature of the sunlight from the heliostats is boosted until a little black plate receiver glows white, which means it is more than 1,800 degrees, which is a temperature that is enough to manufacture industrial products, including cement, without using the usual fossil fuels.
Using sunlight instead of fossil fuels can cut up to 10 percent of global greenhouse gas emissions.
Some Solar Arrays Could Use Improvement
Solar arrays similar to the Heliogen heliostats have been used for making electricity and have even drilled for oil. But those arrays produce up to 1,000 degrees and then peak.
This is because each of those heliostats is individually calibrated, and over time they fall out of alignment with the others, so that all of the heliostats in the arrays aren’t working as a group, diminishing performance.
How Heliogen Automated Solar Arrays Solved a Temperature Problem
With Heliogen, the solar arrays are automated so that cameras that are on top of the tower do a scan of the sky, and there is software that does an image analysis so that each individual mirror is in the optimal position, and can rotate in increments that are smaller than 1/160 of a degree.
With this kind of precision and efficiency, heat can be delivered 20 percent more cheaply than with fossil fuels.
Heliogen Helps Green Up the Manufacturing Process
Heliogen mounted a kiln on top of the tower in order to directly heat limestone, a step in the manufacture of cement, to show the application of their concept.
They hope to partner up with commercial partners with locations that Heliogen requires. Work is being done on building a receiver that can cope with temperatures above 2,700 degrees.
When looking at those kind of temperatures, synthetic hydrogen can be created. This can replace oil-based fuels.
Considering the importance of cement and steel, it is a great discovery to find a way to make it clean and green.