- Rooftop Revolution
- Danny Kennedy
- 1105字
- 2021-03-30 03:46:36
Electricity 101
We already get our energy from the sun—we just do it in the most laughably inefficient way imaginable. In short, fossil fuels—that is, coal, oil, and natural gas—are the sun’s energy, stored in the form of 200-million-year-old plants and extracted today by dangerous, costly, environment-destroying methods.
Solar power, by contrast, comes directly from the source. There are no mines and no rigs—a solar panel just sits in the sun, takes in sunlight, and turns that light into electricity right at the point of use. There’s no costly and unsightly transportation, no danger of explosion or mine collapse, no mountaintop removal, no Fukushima or Deepwater Horizon, and no spilling or killing required. Just clean, cheap energy.
You don’t have to be an energy expert to see how strong the case for solar power is. I’ve spent my adult life fighting on the front lines of the Rooftop Revolution, working around, with, and often in spite of the energy industry, yet I have no formal training as an electrical engineer. So I can tell you, in layperson’s terms, what you need to know before joining this fight.
How did electricity become ubiquitous and affordable for most Americans?
The machines that make the electricity became standardized, and the businesses that delivered them scaled. The machine most commonly used to make electricity in the United States and elsewhere is the steam turbine, developed by a British engineer in the 1880s, which extracts thermal energy from pressurized steam. That pressurized steam is created by boiling water, which is heated by burning various forms of fossil fuels. We get those fossil fuels in a variety of ways: open pit mines, shaft mines, drilling rigs on land and sea, and “fracking”—or geologic fracturing—which is the propagation of fractures in a rock layer by pumping high-pressure liquid down a hole to release natural gas locked in the sediments and fissures.
All of these aforementioned fuels store energy in chemical bonds; the energy is released when they’re burned. The energy got there hundreds of millions of years ago, when these fuels were plants, through the process of photosynthesis: the sun put that energy there. Most of the world’s coal, for instance, comes from the fossilized remains of dinosaur-era plants, hence the term fossil fuel.
See what I mean about a “laughably inefficient way” to get power from the sun?
Coal is mined from holes in the ground—often from shafts but increasingly, due to the use of machinery, from open pits. Humans have been extracting coal from shaft mines for nearly a millennium—and it’s a hugely dangerous enterprise, as you often hear about in the news. Every year thousands die in mine disasters, especially in China, as that country slakes its thirst for low-cost coal. Aside from the human costs, mining has well-known environmental repercussions, such as water pollution, mountain-top removal, and forest clear cutting.
Sucking oil and gas—fossil fuels in liquid or gaseous form—from beneath the ground is a similarly invasive process. While the hole in the ground isn’t usually as large as the holes caused by mines, the cumulative impact of a drilling field can be quite extensive. I spent a year documenting one such project in Papua New Guinea for an academic thesis in human geography, and it took me the better part of two months just to walk around the drill sites that fed one pipeline in the mountains near Lake Kutubu, the second-largest high-altitude lake in the world. I saw firsthand the spills, helicopter accidents, invasive logging, and other ecological effects that made this “best in breed” oil project pretty high impact. Offshore rigs are similarly dangerous, as we recently saw in BP’s devastating oil spill in the Gulf of Mexico.
Gas drilling is a little different. It requires a large industrial infrastructure nearby to liquefy or pressurize the gas for transport in some form. A new gas project off Australia’s northwest coast has so far cost $40 billion just to get up and running. In the United States and elsewhere, getting to natural gas increasingly requires fracking, which is quite controversial because the liquids used are frequently toxic and because the volumes of fluids injected underground are causing groundwater contamination and even earthquakes. We all know that mining and drilling are pretty ugly, but we rarely make the connection between this ugliness and that little light that comes on every time we open the fridge.
Perhaps the biggest problem that we inadvertently exacerbate when we use electricity is climate change (or global warming, as it’s also called): when fossil fuels release the energy locked in chemical-based bonds from plants that once captured carbon dioxide, they also release some of that carbon dioxide into the atmosphere. The way we currently create and process energy releases much of this carbon dioxide pollution. Many books have been written about the subject of climate change, and this is not one of them. Every relevant, reputable scientist in the field has shown that the way we currently create and process energy is a cause of climate change. If we don’t slow the steady rise of global warming, our planet will be beset by more drought, more floods, more hunger, more disease, and more-extreme weather as time progresses. Even if we could clean up all the pollution or accept all the other impacts of the fossil-fuel-extraction industry, we can’t afford to accept the worsening of climate change that burning these fuels causes.
Then there are nukes. A nuclear power plant uses radiation from uranium, instead of fossil fuels, to boil water and create the steam for its steam turbines. The problems with nukes are many, from uranium mining to nuclear waste, which can kill many things living nearby for generations—think of the Chernobyl and Fukushima nuclear disasters—and because of these risks, new nuclear plants are virtually uninsurable (that is, expensive)!
It’s worth noting that turbines can be powered by forces other than steam, the most common being hydroelectric turbines, which capture and transmit the kinetic energy of falling water. Similarly, wind turbines use the power of naturally occurring wind to create energy, which is also sneakily due to the sun’s heating parts of the atmosphere, changing pressure, and causing wind. Like solar, wind is a wonderfully clean and renewable energy source.