Shining a Light on Solar

Solar power is harnessed in a number of ways, including some solar-thermal solutions that concentrate sunlight directly onto water-filled vessels—to boil water, generate steam, and spin a turbine much like the fossil-fuel-based electricity technologies. There are also straight solar hot-water systems, which heat our water only for direct use—not to create electricity—and are very efficient ways to create hot-water service.

But the solar power that I most want to focus on—because it’s the real game changer—is what’s known as photovoltaics, a method of generating electric power by converting solar radiation (photo) into direct-current electricity (voltaic) using semiconductors. When people talk about solar panels, they’re talking about this technology, though the systems range in size, from one small cell (for instance, to power a single light in Zambia) to 10 panels (to power a home in California) to 400,000 panels (to power a city in Crimea).

Solar panels are often called modules because they can be customized to serve any size electricity demand. This alone makes them a remarkably disruptive technology to the electricity industry. Better yet, they don’t require fuel or produce pollution. The production of the panels may cause some pollution, as the production of any manufactured goods does, but it’s minuscule compared with the production of fossil fuels, and it can be contained in a closed production process. Plus, solar-panel components are completely recyclable—something fossil-fuel industries can’t claim about their products—and they pay back the energy put into them in the first few years of operation.

A solar panel at work is like magic in the sense Arthur C. Clarke meant when he said, “Any sufficiently advanced technology is indistinguishable from magic.” Here we have light shining on the surface of the silicon cells, creating an electric current; it’s a tiny amount, but sometimes that’s enough. For instance, there’s my wristwatch, which I’ve had for nearly a decade and have never had to wind or replace a battery. It has a tiny amount of photovoltaic silicon on its face, and that provides the power for the mechanism day in and day out. The minuscule current of electricity that this cell makes can be joined with currents from a series of silicon cells that make up a solar panel, which in turn can be strung together to form an even bigger flow of electricity.

When you hear energy experts talk about “loads,” they’re referring to electricity usage. Solar panels can be quite close to loads and sized appropriately. This is different from steam-based technologies, which tend to be far from loads and oversized, so they’re sure to meet demand. Solar power is not only clean but also local. And now it’s the most cost-effective.

Before we proceed, I should explain how we measure power and energy: “Power” is what we can directly use, like the water we pour into our mouths. “Energy” is like all the water stored up in the clouds; it has the potential to come down to us, but until and unless it does we may go thirsty. That is to say, we can have energy but not necessarily usable power. Power is measured in kilowatts, and electricity comes in kilowatt-hours because we’re measuring how long a source can provide an amount of power. Your electricity bill charges you per kilowatt-hour.

The energy potential in 20 days of sunshine falling on Earth is the same as that of all the coal, oil, and natural gas known to humans. We may find more fossil fuels at some point, but solar power is effectively infinite, unlike fossil fuels, which someday, especially at the rate we’re using them, will run out. They are governed by the reality of scarcity and become more expensive the more you use them. Sunshine as fuel renews every day. It is abundant and becomes cheaper the more you use it. I admit that there’s an assumption here—that the sun will rise and shine on us—but the day it doesn’t, we’ll have bigger issues to deal with than whether the toaster’s working!

So if you understand the significant potential of solar energy, you’re going to be excited about the reality of solar panels to tap it. They take 15 percent of sunlight’s energy and convert it into useable power. And solar panels are more affordable and more powerful each year. These 2-by-3-foot framed modules of glass and aluminum, sandwiching some slices of silicon arrayed in a 60- or 72-cell format, and the economy that will emerge as part and parcel of them have the potential to completely negate the entire grid infrastructure built around steam turbines since the end of the nineteenth century.

The grid, as it exists now, consists of large generators that convert the energy stored in fossil fuels into electricity that’s then sent over cables and wires into our homes and businesses. We’re dumb recipients down a one-way line. The growing demand for electricity, plus constraints on transmission systems and the environmental costs of fossil fuels, has resulted in many concerns about the limits to this approach among politicians and others hoping to keep the lights on. Solar technology allows individuals to become producers of power, too, and to engage in the creation of the electricity they use.

This shift has been described as enabling electricity users to become “prosumers”—producer-consumers—on a smart grid, a bit like the Internet has allowed individuals to not simply consume media content but also create and share it. It need not be a frightening transition to be more involved in energy production while we consume it. Society just needs businesses that make doing so seamless and simple—and maybe a little sexy. The economics can already make it worth our while.

I call this change from dirty-energy dependency to a portfolio of clean, distributed energy solutions the Solar Ascent because solar will be the primary source of power. This transition will be triggered by this decade’s Rooftop Revolution, in which many millions take part in the Solar Ascent by producing their own power on their own places. In other words, the longer-term evolution will be driven by mass adoption of solar panels on our rooftops in a historic burst of resistance to the powers that be.

The previous big energy revolution was the Industrial Revolution. Coal combined with the power of steam engines created new opportunities in our economy and changed the world. Replacing our agricultural society (before the steam engine, most work was fueled by eating plants with their more freshly stored sunlight) with an industrial society unleashed a boom in productivity and innovation that has lasted for centuries. The Rooftop Revolution will launch similarly world-changing outcomes if it succeeds. If it doesn’t, we’ll be stuck with the impacts of the dirty-energy sources that steam power bequeathed to us.