Varun Sivaram - Taming the Sun: Innovations to Harness Solar Energy and Power the Planet

In 2012, I met the mayor of Los Angeles, Antonio Villaraigosa, at a reception in Washington, D.C. At the time, I was a PhD student at the University of Oxford, where I was developing new materials to generate more electricity at lower cost than existing solar panels. When I shared my research with the mayor, he wrote his cell-phone number on a card and told me to call him. I assumed that he was just being polite, so I returned to Oxford and got busy finishing my thesis. A few days later, the deputy mayor emailed asking if Id like to serve as the mayors senior advisor and, if so, could I speak with the mayor tomorrow about the role. Within a week, Id moved to Los Angeles.

I arrived underprepared but overconfident. I had never installed a single solar panel, yet Mayor Villaraigosa envisioned deploying more solar power than any other city in the country. Nevertheless, I was well versed in the latest advances made in scientific labs around the world, so I believed I could fulfill the mayors vision by using brand new solar technologies far superior to the off-the-shelf solar panels that every other city was deploying.

I would soon discover this was nave. Shortly after starting at the mayors office, I had the bright idea to hitch a ride on a city helicopter. A few times a week, the Department of Water and Power would send one to survey the precious aqueduct that makes Los Angeles an improbable oasis in the middle of a desert. Roughly along the patrol route, on the western tip of the Mojave Desert, was a recently installed solar power project that used conventional solar panels. A helicopter would be a great way to get a look at it.

As we approached the solar farm, two thousand football fields worth of solar panels stretched out as far as I could see in every direction, all of them tilting south to bask in the rays of summer. To my delight, the pilot obliged my request to fly closer to the ground. As we swooped in, I could see the details on each panel, down to the individual cells of siliconmottled blue-black wafers about as big as your handthat convert nearly 20 percent of the sunlight striking them to electricity. Connecting these repeating units togetherby first wiring cells together into panels and then panels together into a massive solar farmmakes it possible to generate ever more energy, limited only by the amount of available land.

That helicopter ride introduced me to the massive scale of solar power. I had built only fingernail-sized solar cells in my ivory tower (actually, in a laboratory in a limestone basement) at Oxford. Witnessing solar in the wild disabused me of the fiction that the city could immediately deploy newly invented cells on the scale required to realize the mayors vision; billions would be needed to carpet a square mile of desert.

Under Mayor Villaraigosa, Los Angeles would ultimately lead the country in its deployment of solar power. And we did so with tried-and-true technology. Silicon solar panels have been used for decades, and today the Chinese can mass-produce them reliably. By using those panels, we minimized the risk that deploying them would cost more than expected or that they would stop working. The mayors quest to use more solar poweran erratic source of electricity that only works when the sun is shiningwas hard enough, given the citys mandate to keep the lights on for 4 million Angelenos. So we strove to avoid taking any further risks on unproven solar technologies.

From that experience, I learned that no single perspective will suffice to realize the enormous potential of solar energy (the sun beams down more energy to the Earths surface in an hour than the world uses in a year). For instance, Ron Nicholsthe practical-minded head of the citys electricity utilityremarked to me that adding renewable energy to the electricity grid is like repairing the engine of a 747 midflight; the last thing you want to do is add another moving part by trying out a new technology. But my colleagues in academia had shown me that solar technologies far superior to todays already exist in the lab. If they could be refined and mass-produced, they could one day make it possible to harness the suns energy much more efficiently and cheaply.