Sunlight has become the fastest-growing and mature energy source with global investments exceeding two trillion dollars in the past ten years. It now makes the cheapest electricity beating coal, natural gas, and petroleum crude by wide margins.
But current solar technology has a few limitations that restrict its potential to replace fossil fuels. For example, current solar technology cannot generate the high temperatures required for melting steel or making cement.
This prevents solar’s industrial use. But there is good news. Multiple solar research startups have reported breakthroughs in generating higher temperatures and other areas. Research in three critical areas has the potential to make solar the dominant energy source in less than a decade.
First, industry application. Existing technology is simple. Lenses and mirrors focus sun rays to produce heat. Much like the way we burn paper using hand lens and sunlight. We call this Concentrating Solar Power (CSP) technique.
The problem is the best CSP equipment could generate less than 1000°C of temperature – suitable for heating or making electricity but at least 400°C short for any industrial use. Cement or steel making happens in the temperature range of 1400-1600°C. This compels most industries to use the energy derived from fossil fuels. Now a few startups are reporting significant advances in this area.
Bill Gates backs the most promising one. It could achieve temperature much above 1600°C in field trials. The firm used computer programmes to align large numbers of mirrors to produce a laser-like sharp light beam, hot enough to melt steel. The startup hopes to generate much higher temperatures than this. It plans to use the heat to produce hydrogen from water at the industrial scale.
This will allow the use of solar energy not only for industrial processing but also for transport. Large vehicles like ships, planes, and trucks can use hydrogen as a fuel.